gh-15512: Sync upstream Firefox to version 156.0.1 (gh-15515)

gh-15513: URL bar and sidebar should have transparency when available (gh-15514)
gh-15438: Fix library compact mode offset (gh-15504)
2026-09-25 13:38:18 +00:00 · 2026-09-22 15:45:14 +02:00 · 2026-09-22 14:08:20 +02:00 · 2026-09-21 20:00:10 +02:00 · 2026-09-21 16:52:29 +02:00 · 2026-09-21 16:51:05 +02:00
263 changed files with 17019 additions and 4899 deletions
@@ -23,7 +23,6 @@ jobs:
      fail-fast: false
      matrix:
        arch: [x86_64, aarch64]
    runs-on: ${{ matrix.arch == 'x86_64' && 'macos-15-intel' || 'macos-26' }}
    steps:
@@ -27,7 +27,6 @@ jobs:
      fail-fast: false
      matrix:
        arch: [x86_64, aarch64]
    runs-on: ${{ inputs.release-branch == 'release' && 'windows-latest' || 'windows-latest' }}
    steps:
@@ -1 +1 @@
-1.94.1
+1.95.0
@@ -34,8 +34,8 @@ Zen is a firefox-based browser with the aim of pushing your productivity to a ne
 ### Firefox Versions
- [`Release`](https://zen-browser.app/download) - Is currently built using Firefox version `155.0.1`!
+- [`Release`](https://zen-browser.app/download) - Is currently built using Firefox version `156.0.1`!
- [`Twilight`](https://zen-browser.app/download?twilight) - Is currently built using Firefox version `RC 155.0.1`!
+- [`Twilight`](https://zen-browser.app/download?twilight) - Is currently built using Firefox version `RC 156.0.1`!
 ### Contributing
@@ -1 +1 @@
-b6d45eac914fd4886c9b6e5f1447f613771228ff
+782b15a7c771795a323e9403340c029e7c8d7629
@@ -147,9 +147,9 @@ function SignAndPackage($name) {
    $env:ZEN_SETUP_EXE_PATH="$PWD\windsign-temp\windows-x64-obj-$name\browser\installer\windows\instgen\setup.exe"
    if ($name -eq "arm64") {
-        $env:WIN32_REDIST_DIR="$PWD\win-cross\vs2026\VC\Redist\MSVC\14.50.35710\arm64\Microsoft.VC145.CRT"
+        $env:WIN32_REDIST_DIR="$PWD\win-cross\vs2026\VC\Redist\MSVC\14.51.36231\arm64\Microsoft.VC145.CRT"
    } else {
-        $env:WIN32_REDIST_DIR="$PWD\win-cross\vs2026\VC\Redist\MSVC\14.50.35710\x64\Microsoft.VC145.CRT"
+        $env:WIN32_REDIST_DIR="$PWD\win-cross\vs2026\VC\Redist\MSVC\14.51.36231\x64\Microsoft.VC145.CRT"
    }
    $env:MAR="..\\build\\windows\\mar.exe"
@@ -53,7 +53,10 @@ fi
 if test "$ZEN_RELEASE"; then
  ac_add_options --enable-clang-plugin
-  ac_add_options --enable-bootstrap=-sccache
+  
  if ! test "$ZEN_DISABLE_BOOTSTRAP"; then
    ac_add_options --enable-bootstrap=-sccache
  fi
  ac_add_options --enable-optimize
@@ -69,16 +72,11 @@ if test "$ZEN_RELEASE"; then
  ac_add_options --disable-geckodriver
  ac_add_options --disable-rust-tests
-  if ! test "$ZEN_DISABLE_LTO"; then
+  if test "$ZEN_DISABLE_LTO"; then
-    # only enable full LTO when ZEN_RELEASE_BRANCH is 'release'
+    ac_add_options --disable-lto
-    if test "$ZEN_RELEASE_BRANCH" = "release"; then
+  else
-      # TODO: make it "full" once we have the resources to build it
+    export MOZ_LTO=cross,thin
-      export MOZ_LTO=cross,full
+    ac_add_options --enable-lto=cross,thin
      ac_add_options --enable-lto=cross,full
    else
      export MOZ_LTO=cross,thin
      ac_add_options --enable-lto=cross,thin
    fi
  fi
  mk_add_options MOZILLA_OFFICIAL=1
@@ -9,6 +9,9 @@ if test "$ZEN_RELEASE"; then
        # Enable Profile Guided Optimization
        if ! test "$ZEN_GA_DISABLE_PGO"; then
            export MOZ_LTO=cross,full
            ac_add_options --enable-lto=cross,full
            if test "$ZEN_GA_GENERATE_PROFILE"; then
                mk_add_options "export MOZ_AUTOMATION_PACKAGE_GENERATED_SOURCES=0"
                ac_add_options --enable-profile-generate=cross
@@ -15,9 +15,9 @@ if test "$ZEN_CROSS_COMPILING"; then
  CROSS_COMPILE=1
  if test "$SURFER_COMPAT" = "aarch64"; then
-    export WIN32_REDIST_DIR="$WINSYSROOT/VC/Redist/MSVC/14.50.35710/arm64/Microsoft.VC145.CRT"
+    export WIN32_REDIST_DIR="$WINSYSROOT/VC/Redist/MSVC/14.51.36231/arm64/Microsoft.VC145.CRT"
  else
-    export WIN32_REDIST_DIR="$WINSYSROOT/VC/Redist/MSVC/14.50.35710/x64/Microsoft.VC145.CRT"
+    export WIN32_REDIST_DIR="$WINSYSROOT/VC/Redist/MSVC/14.51.36231/x64/Microsoft.VC145.CRT"
  fi
 fi
@@ -45,6 +45,9 @@ if test "$ZEN_CROSS_COMPILING"; then
      ac_add_options --enable-profile-use=cross
      ac_add_options --with-pgo-profile-path=$(echo ~)/artifact/merged.profdata
      ac_add_options --with-pgo-jarlog=$(echo ~)/artifact/en-US.log
      export MOZ_LTO=cross,full
      ac_add_options --enable-lto=cross,full
    fi
  fi
 fi
@@ -26,3 +26,5 @@ files:
    translation: browser/browser/zen-space-routing.ftl
  - source: en-US/browser/browser/zen-command-palette.ftl
    translation: browser/browser/zen-command-palette.ftl
  - source: en-US/browser/browser/zen-share.ftl
    translation: browser/browser/zen-share.ftl
@@ -68,6 +68,10 @@ zen-settings-workspaces-sync =
    .label = Sync your sidebar across devices
    .description = Keep your workspaces, pinned tabs and folders in sync on all your devices through your Mozilla account.
 zen-settings-normal-tabs-sync =
    .label = Include unpinned tabs
    .description = Also sync the regular tabs of each space, not just your pinned tabs and folders.
 zen-settings-workspaces-sync-unpinned-tabs =
    .label = Sync only pinned tabs in workspaces
@@ -5,6 +5,8 @@
 zen-action-toggle-compact-mode = Toggle Compact Mode
 zen-action-open-theme-picker = Open Theme Picker
 zen-action-new-split-view = New Split View
 zen-action-unsplit-view = Expand current view
 zen-action-new-space = New Space
 zen-action-new-folder = New Folder
 zen-action-copy-current-url = Copy Current URL
 zen-action-settings = Settings
@@ -18,6 +20,9 @@ zen-action-new-boost = New Boost
 zen-action-next-space = Next Space
 zen-action-previous-space = Previous Space
 zen-action-close-tab = Close Tab
 zen-action-reopen-closed-tab = Reopen Closed Tab
 zen-action-duplicate-tab = Duplicate Current Tab
 zen-action-reset-pinned-tab = Reset Pinned Tab
 zen-action-reload-tab = Reload Tab
 zen-action-reload-tab-without-cache = Reload Tab Without Cache
 zen-action-next-tab = Next Tab
@@ -34,3 +39,4 @@ zen-action-switch-to-dark-mode = Switch to Dark Mode
 zen-action-print = Print
 zen-action-focus-on = Focus on
 zen-action-extension = Extension
 zen-action-open = Open
@@ -0,0 +1,112 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 zen-library-button =
    .label = Library
    .tooltiptext = Library
 library-footer-close-button =
    .tooltiptext = Close library
 library-footer-donate-button =
    .tooltiptext = Donate to Zen
 library-history-section-title = History
 library-downloads-section-title = Downloads
 library-boosts-section-title = Boosts
 library-media-section-title = Media
 library-spaces-section-title = Spaces
 library-filter-button = Filter
 library-filter-done = Done
 library-history-filter-title = Filter History…
 library-history-filter-when = When was it visited?
 library-filter-today = Today
 library-filter-week = This Week
 library-filter-month = This Month
 library-history-filter-sort = Sort by
 library-history-sort-date = By Date
 library-history-sort-site = By Site
 library-history-sort-most-visited = By Most Visited
 library-history-sort-last-visited = By Last Visited
 library-history-site-other = Other
 library-history-search-placeholder =
    .placeholder = Search History…
 library-history-empty = No history found
 library-media-empty = No media found
 library-media-search-placeholder =
    .placeholder = Search Media…
 library-media-loading = Looking for media…
 library-media-opt-in-title = Your Media in the Library
 library-media-opt-in-body = Quickly grab screenshots, images and videos from your computer by showing them in the Zen Library.
 library-media-opt-in-button = Show Media
 library-media-opt-in-note = Media never leaves your computer and is not viewable by anyone but you.
 library-media-filter-title = Filter Media…
 library-media-filter-folders = Where to look
 library-media-open-in = Open in { $app }
 library-media-close =
    .title = Close
 library-media-previous =
    .title = Previous
 library-media-next =
    .title = Next
 library-media-more =
    .title = More options
 library-media-menu-open =
    .label = Open
 library-media-menu-copy =
    .label = Copy
 library-history-forget-button =
    .title = Remove from history
 library-history-reopen-button =
    .title = Reopen page
 library-downloads-empty = No downloads found
 library-downloads-more-button =
    .title = More options
 library-downloads-menu-open =
    .label = Open { $name }
 library-downloads-menu-copy =
    .label = Copy { $name }
 library-downloads-menu-hide =
    .label = Hide from Zen
 library-downloads-menu-trash =
    .label = Move to Trash
 library-downloads-opening-in = { PLATFORM() ->
    [macos] Opening in Finder…
    [windows] Opening in File Explorer…
   *[other] Opening in file manager…
 }
 library-downloads-cancel-button =
    .title = Cancel download
 library-downloads-filter-title = Filter Downloads…
 library-downloads-filter-type = File type
 library-downloads-filter-when = When was it downloaded?
 library-downloads-type-images = Images
 library-downloads-type-video = Video
 library-downloads-type-audio = Audio
 library-downloads-type-documents = Documents
 library-downloads-type-archives = Archives
 library-downloads-type-apps = Apps
 library-downloads-retry-button =
    .title = Retry download
 library-spaces-theme-button =
    .title = Change theme
 library-spaces-move-button =
    .title = Drag to reorder
 library-spaces-actions-button =
    .tooltiptext = More options
 library-spaces-icon-button =
    .title = Change icon
 library-spaces-name-button =
    .title = Rename space
 library-boosts-search-placeholder =
    .placeholder = Search Boosts…
 library-boosts-empty = No boosts yet
 library-boosts-toggle =
    .aria-label = Enable boost
 library-boosts-menu-edit =
    .label = Edit Boost
@@ -0,0 +1,43 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 zen-share-space =
    .label = Share Space…
 zen-share-folder =
    .label = Share Folder…
 zen-share-split-view =
    .label = Share Split View…
 zen-share-link-copied-toast = Share link copied!
 zen-share-link-expires-description = Anyone with the link can open it until { $date }
 zen-share-link-permanent-description = Anyone with the link can open it
 zen-share-error-toast = Couldn't create a share link
 zen-share-error-auth-description = The share server rejected your key
 zen-share-error-too-large-description = This share is too big to upload
 zen-share-error-rate-limited-description = You're sharing too fast, try again in a minute
 zen-share-error-network-description = Couldn't reach the share server
 zen-share-error-empty-description = There's nothing shareable here
 zen-share-error-server-description = The share server returned an error
 zen-share-overlay-loading = Loading shared tabs…
 zen-share-overlay-from-space = A Space from { $name }
 zen-share-overlay-from-folder = A Folder from { $name }
 zen-share-overlay-shared-with-you = Shared with you
 zen-share-overlay-add-space = Add Space to Zen
 zen-share-overlay-add-folder = Add Folder to Zen
 zen-share-imported-toast = Added to your browser!
 zen-share-import-error-toast = Couldn't import this share
 zen-share-import-error-dead-description = The link has expired or doesn't exist
 zen-share-import-error-invalid-description = The shared data is invalid
 zen-share-confirm-title = Share link
 zen-share-confirm-dialog =
    .buttonlabelaccept = Share
 zen-share-confirm-description = Zen uploads a copy of these tabs to the share server and copies a link anyone can open. The link expires after 30 days.
 zen-share-confirm-anonymous = Sharing is anonymous unless you add a name.
 zen-share-confirm-name-input =
    .placeholder = Your name (optional)
 zen-share-confirm-dont-ask =
    .label = Don't ask me again
@@ -24,6 +24,11 @@ zen-welcome-default-search-description = Choose your default search engine. You
 zen-welcome-essentials-title = Choose the apps you use most.
 zen-welcome-essentials-description = Select your favorite apps to keep them handy in your sidebar.
 zen-welcome-block-ads-title = Block ads and trackers?
 zen-welcome-block-ads-description = { -brand-short-name } can install uBlock Origin for you, so pages load cleaner and faster. You can remove it any time.
 zen-welcome-block-ads-yes = <strong>YES</strong>, block ads for me.
 zen-welcome-block-ads-no = <strong>NO</strong>, show me everything.
 zen-welcome-workspace-colors-title = Your space, your colors.
 zen-welcome-workspace-colors-description = Personalize your browser by giving each space its own unique color identity.
@@ -0,0 +1,15 @@
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 - name: zen.library.enabled
  value: "@IS_TWILIGHT@"
 - name: zen.library.last-tab
  value: "history"
 - name: zen.library.media.enabled
  value: false
 - name: zen.library.media.folders
  value: "downloads,documents,pictures"
@@ -2,5 +2,18 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
- name: zen.share.enabled
+- name: zen.share.base-url
  value: "https://share.zen-browser.app"
 - name: zen.share.secret-key
  value: ""
 - name: zen.share.display-name
  value: ""
 # Allow zen.share.display-name to be synced across devices.
 - name: services.sync.prefs.sync.zen.share.display-name
  value: true
 - name: zen.share.dont-ask-before-sharing
  value: false
@@ -8,3 +8,9 @@
 - name: zen.spaces-sync.debug
  value: false
 - name: zen.spaces-sync.normal-tabs
  value: false
 - name: services.sync.prefs.sync.zen.spaces-sync.normal-tabs
  value: true
@@ -20,6 +20,7 @@
 - name: zen.theme.acrylic-elements
  value: "@IS_TWILIGHT@"
 - name: zen.theme.disable-lightweight
  value: true
@@ -1,8 +1,8 @@
 diff --git a/.stylelintignore b/.stylelintignore
-index 185490999507b8a5032977237af50f5e61c71df1..77c1635d90c6480af4ebd3c6e3ec49780eaca571 100644
+index 185490999507b8a5032977237af50f5e61c71df1..4b1b1dc76d316f38f60c90e6cbd74d9569800d04 100644
 --- a/.stylelintignore
 +++ b/.stylelintignore
-@@ -106,3 +106,19 @@ build/pgo/blueprint/**/*.css
+@@ -106,3 +106,20 @@ build/pgo/blueprint/**/*.css
 # under our control or we don't want to modify at this point:
 testing/web-platform/mozilla/
 testing/web-platform/tests/
@@ -20,5 +20,6 @@ index 185490999507b8a5032977237af50f5e61c71df1..77c1635d90c6480af4ebd3c6e3ec4978
 +zen/split-view/zen-split-view.css
 +zen/spaces/zen-workspaces.css
 +zen/common/styles/zen-toolbar.css
 +zen/common/styles/zen-single-components.css
 +
 +*.inc
@@ -1,5 +1,5 @@
 diff --git a/browser/base/content/navigator-toolbox.inc.xhtml b/browser/base/content/navigator-toolbox.inc.xhtml
-index dd2f391096968564086911c532f696dc7ffb8ae1..c968e5f0ebb5f0151fb124bafe10d8d5361e060f 100644
+index a76bb7aae7636c07989a4acb35281777d3103505..d35aa0457307e95ad00464861fcee2827325193e 100644
 --- a/browser/base/content/navigator-toolbox.inc.xhtml
 +++ b/browser/base/content/navigator-toolbox.inc.xhtml
@@ -2,7 +2,7 @@
@@ -26,7 +26,7 @@ index dd2f391096968564086911c532f696dc7ffb8ae1..c968e5f0ebb5f0151fb124bafe10d8d5
   <toolbar id="TabsToolbar"
            class="browser-toolbar browser-titlebar"
            fullscreentoolbar="true"
-@@ -54,6 +58,8 @@
+@@ -56,6 +60,8 @@
           <html:sidebar-pins-promo id="drag-to-pin-promo-card"></html:sidebar-pins-promo>
           <arrowscrollbox id="pinned-tabs-container" orient="horizontal" clicktoscroll=""></arrowscrollbox>
           <splitter orient="vertical" id="vertical-pinned-tabs-splitter" resizebefore="sibling" resizeafter="none" hidden="true"/>
@@ -35,7 +35,7 @@ index dd2f391096968564086911c532f696dc7ffb8ae1..c968e5f0ebb5f0151fb124bafe10d8d5
           <hbox class="tab-drop-indicator" hidden="true"/>
           <arrowscrollbox id="tabbrowser-arrowscrollbox" orient="horizontal" flex="1" clicktoscroll="" scrolledtostart="" scrolledtoend="">
             <tab is="tabbrowser-tab" class="tabbrowser-tab" selected="" visuallyselected="" fadein=""/>
-@@ -73,6 +79,7 @@
+@@ -75,6 +81,7 @@
                               tooltip="dynamic-shortcut-tooltip"
                               data-l10n-id="tabs-toolbar-new-tab"/>
           <html:span id="tabbrowser-tab-a11y-desc" hidden="true"/>
@@ -43,7 +43,7 @@ index dd2f391096968564086911c532f696dc7ffb8ae1..c968e5f0ebb5f0151fb124bafe10d8d5
         </tabs>
         <toolbarbutton id="new-tab-button"
-@@ -99,9 +106,10 @@
+@@ -102,9 +109,10 @@
     <toolbarbutton class="content-analysis-indicator toolbarbutton-1 content-analysis-indicator-icon"/>
@@ -54,4 +54,12 @@ index dd2f391096968564086911c532f696dc7ffb8ae1..c968e5f0ebb5f0151fb124bafe10d8d5
 +</hbox>
   <toolbar id="nav-bar"
-            class="browser-toolbar chromeclass-location"
+            class="browser-toolbar"
@@ -180,7 +188,6 @@
         <toolbartabstop/>
         <html:moz-urlbar id="urlbar"
               class="urlbar"
 -              popover="manual"
               pageproxystate="invalid"
               unifiedsearchbutton-available=""
               sap-name="urlbar">
@@ -21,3 +21,5 @@
 #include ../../../zen/boosts/jar.inc.mn
 #include ../../../zen/live-folders/jar.inc.mn
 #include ../../../zen/space-routing/jar.inc.mn
 #include ../../../zen/share/jar.inc.mn
 #include ../../../zen/library/jar.inc.mn
@@ -16,6 +16,7 @@
  <command id="cmd_zenSplitViewUnsplit" />
  <command id="cmd_zenSplitViewLinkInNewTab" />
  <command id="cmd_zenSplitViewContextMenu" />
  <command id="cmd_zenCtxShareSplitView" />
  <command id="cmd_zenNewEmptySplit" />
  <!-- Workspace commands -->
@@ -40,6 +41,7 @@
  <command id="cmd_contextZenRemoveFromEssentials" />
  <command id="cmd_zenCtxDeleteWorkspace" />
  <command id="cmd_zenCtxShareWorkspace" />
  <command id="cmd_zenUnloadWorkspace" />
  <command id="cmd_zenUnloadAllOtherWorkspace" />
  <command id="cmd_zenOpenSpaceRoutingSettings" />
@@ -70,4 +72,6 @@
  <command id="cmd_zenNewLiveFolder" />
  <command id="cmd_zenDuplicateTab" />
  <command id="cmd_zenToggleLibrary" />
 </commandset>
@@ -12,4 +12,6 @@
 <link rel="localization" href="browser/zen-boosts.ftl"/>
 <link rel="localization" href="browser/zen-live-folders.ftl"/>
 <link rel="localization" href="browser/zen-space-routing.ftl"/>
 <link rel="localization" href="browser/zen-share.ftl"/>
 <link rel="localization" href="browser/zen-library.ftl"/>
 </linkset>
@@ -32,6 +32,7 @@
  <menuitem id="context_zenUnloadAllOtherWorkspace" data-l10n-id="zen-workspaces-panel-unload-others" command="cmd_zenUnloadAllOtherWorkspace"/>
  <menuseparator/>
  <menuitem data-l10n-id="zen-panel-ui-workspaces-create" command="cmd_zenOpenWorkspaceCreation"/>
  <menuitem id="context_zenShareWorkspace" data-l10n-id="zen-share-space" command="cmd_zenCtxShareWorkspace"/>
  <menuitem id="context_zenDeleteWorkspace" data-l10n-id="zen-workspaces-panel-context-delete" command="cmd_zenCtxDeleteWorkspace"/>
  <menuseparator/>
  <menuitem id="context_zenSpaceRoutingSettings" data-l10n-id="zen-space-routing-settings" command="cmd_zenOpenSpaceRoutingSettings"/>
@@ -55,6 +56,7 @@
    <menupopup />
  </menu>
  <menuitem id="context_zenFolderToSpace" data-l10n-id="zen-folders-panel-convert-folder-to-space" />
  <menuitem id="context_zenShareFolder" data-l10n-id="zen-share-folder"/>
  <menuseparator />
  <menuitem id="context_zenFolderUnpack" data-l10n-id="zen-folders-panel-unpack-folder"/>
  <menuitem id="context_zenFolderDelete" data-l10n-id="zen-folders-panel-delete-folder"/>
@@ -1,5 +1,5 @@
 diff --git a/browser/components/customizableui/CustomizableUI.sys.mjs b/browser/components/customizableui/CustomizableUI.sys.mjs
-index 6d1885a54815d10b3a4e79f7e5acd61ab3abb159..3d6e092e7ed126cdee8c32229df2cfa13303d3a3 100644
+index 875f8b03d979353ef44a57c15ef1ae09d33ab730..3d6e092e7ed126cdee8c32229df2cfa13303d3a3 100644
 --- a/browser/components/customizableui/CustomizableUI.sys.mjs
 +++ b/browser/components/customizableui/CustomizableUI.sys.mjs
@@ -13,6 +13,7 @@ ChromeUtils.defineESModuleGetters(lazy, {
@@ -19,7 +19,7 @@ index 6d1885a54815d10b3a4e79f7e5acd61ab3abb159..3d6e092e7ed126cdee8c32229df2cfa1
       },
       false
     );
-@@ -362,27 +363,23 @@ var CustomizableUIInternal = {
+@@ -362,20 +363,15 @@ var CustomizableUIInternal = {
       "back-button",
       "forward-button",
       "stop-reload-button",
@@ -41,27 +41,29 @@ index 6d1885a54815d10b3a4e79f7e5acd61ab3abb159..3d6e092e7ed126cdee8c32229df2cfa1
     this.registerArea(
       CustomizableUI.AREA_NAVBAR,
       {
-         type: CustomizableUI.TYPE_TOOLBAR,
+@@ -383,9 +379,6 @@ var CustomizableUIInternal = {
         overflowable: true,
         defaultPlacements: navbarPlacements,
-        verticalTabsDefaultPlacements: ["alltabs-button", "ai-window-toggle"],
+         verticalTabsDefaultPlacements: [
-+        verticalTabsDefaultPlacements: [
+-          "alltabs-button",
-+        ],
+-          "smartwindow-group-tabs-button",
 -          "ai-window-toggle",
         ],
         defaultCollapsed: false,
       },
-       true
+@@ -410,11 +403,6 @@ var CustomizableUIInternal = {
@@ -406,10 +403,6 @@ var CustomizableUIInternal = {
         type: CustomizableUI.TYPE_TOOLBAR,
         defaultPlacements: [
           "tabbrowser-tabs",
 -          "new-tab-button",
 -          "spring",
 -          "alltabs-button",
 -          "smartwindow-group-tabs-button",
 -          "ai-window-toggle",
         ],
         verticalTabsDefaultPlacements: [],
         defaultCollapsed: null,
-@@ -502,6 +495,7 @@ var CustomizableUIInternal = {
+@@ -507,6 +495,7 @@ var CustomizableUIInternal = {
       CustomizableUI.AREA_NAVBAR,
       CustomizableUI.AREA_BOOKMARKS,
       CustomizableUI.AREA_TABSTRIP,
@@ -69,7 +71,7 @@ index 6d1885a54815d10b3a4e79f7e5acd61ab3abb159..3d6e092e7ed126cdee8c32229df2cfa1
     ]);
     if (AppConstants.platform != "macosx") {
       toolbars.add(CustomizableUI.AREA_MENUBAR);
-@@ -1334,6 +1328,9 @@ var CustomizableUIInternal = {
+@@ -1339,6 +1328,9 @@ var CustomizableUIInternal = {
         placements = gPlacements.get(area);
       }
@@ -79,7 +81,7 @@ index 6d1885a54815d10b3a4e79f7e5acd61ab3abb159..3d6e092e7ed126cdee8c32229df2cfa1
       // For toolbars that need it, mark as dirty.
       let defaultPlacements = areaProperties.get("defaultPlacements");
       if (
-@@ -1842,7 +1839,6 @@ var CustomizableUIInternal = {
+@@ -1847,7 +1839,6 @@ var CustomizableUIInternal = {
         lazy.log.info(
           "Widget " + aWidgetId + " not found, unable to remove from " + aArea
         );
@@ -87,7 +89,7 @@ index 6d1885a54815d10b3a4e79f7e5acd61ab3abb159..3d6e092e7ed126cdee8c32229df2cfa1
       }
       this.notifyDOMChange(widgetNode, null, container, true, () => {
-@@ -1852,7 +1848,7 @@ var CustomizableUIInternal = {
+@@ -1857,7 +1848,7 @@ var CustomizableUIInternal = {
         // We also need to remove the panel context menu if it's there:
         this.ensureButtonContextMenu(widgetNode);
         if (gPalette.has(aWidgetId) || this.isSpecialWidget(aWidgetId)) {
@@ -96,7 +98,7 @@ index 6d1885a54815d10b3a4e79f7e5acd61ab3abb159..3d6e092e7ed126cdee8c32229df2cfa1
         } else {
           window.gNavToolbox.palette.appendChild(widgetNode);
         }
-@@ -2020,16 +2016,16 @@ var CustomizableUIInternal = {
+@@ -2025,16 +2016,16 @@ var CustomizableUIInternal = {
         elem.setAttribute("skipintoolbarset", "true");
       }
     }
@@ -116,7 +118,7 @@ index 6d1885a54815d10b3a4e79f7e5acd61ab3abb159..3d6e092e7ed126cdee8c32229df2cfa1
     // Handle initial state of vertical tabs.
     if (isVerticalTabs) {
       // Show the vertical tabs toolbar
-@@ -2271,6 +2267,10 @@ var CustomizableUIInternal = {
+@@ -2276,6 +2267,10 @@ var CustomizableUIInternal = {
    *   The identifier string of the area that aNode is being inserted into.
    */
   insertWidgetBefore(aNode, aNextNode, aContainer, aAreaId) {
@@ -127,7 +129,7 @@ index 6d1885a54815d10b3a4e79f7e5acd61ab3abb159..3d6e092e7ed126cdee8c32229df2cfa1
     this.notifyDOMChange(aNode, aNextNode, aContainer, false, () => {
       this.setLocationAttributes(aNode, aAreaId);
       aContainer.insertBefore(aNode, aNextNode);
-@@ -4647,7 +4647,7 @@ var CustomizableUIInternal = {
+@@ -4652,7 +4647,7 @@ var CustomizableUIInternal = {
    * For all registered areas, builds those areas to reflect the current
    * placement state of all widgets.
    */
@@ -136,7 +138,7 @@ index 6d1885a54815d10b3a4e79f7e5acd61ab3abb159..3d6e092e7ed126cdee8c32229df2cfa1
     for (let [areaId, areaNodes] of gBuildAreas) {
       let placements = gPlacements.get(areaId);
       let isFirstChangedToolbar = true;
-@@ -4658,7 +4658,7 @@ var CustomizableUIInternal = {
+@@ -4663,7 +4658,7 @@ var CustomizableUIInternal = {
         if (area.get("type") == CustomizableUI.TYPE_TOOLBAR) {
           let defaultCollapsed = area.get("defaultCollapsed");
           let win = areaNode.documentGlobal;
@@ -145,7 +147,7 @@ index 6d1885a54815d10b3a4e79f7e5acd61ab3abb159..3d6e092e7ed126cdee8c32229df2cfa1
             win.setToolbarVisibility(
               areaNode,
               typeof defaultCollapsed == "string"
-@@ -5971,6 +5971,7 @@ export var CustomizableUI = {
+@@ -5976,6 +5971,7 @@ export var CustomizableUI = {
   unregisterArea(aName, aDestroyPlacements) {
     CustomizableUIInternal.unregisterArea(aName, aDestroyPlacements);
   },
@@ -153,7 +155,7 @@ index 6d1885a54815d10b3a4e79f7e5acd61ab3abb159..3d6e092e7ed126cdee8c32229df2cfa1
   /**
    * Add a widget to an area.
    * If the area to which you try to add is not known to CustomizableUI,
-@@ -7946,7 +7947,9 @@ class OverflowableToolbar {
+@@ -7951,7 +7947,9 @@ class OverflowableToolbar {
         );
         if (webExtList && CustomizableUI.isWebExtensionWidget(child.id)) {
@@ -163,7 +165,7 @@ index 6d1885a54815d10b3a4e79f7e5acd61ab3abb159..3d6e092e7ed126cdee8c32229df2cfa1
           webExtList.insertBefore(child, webExtList.firstElementChild);
         } else {
           child.setAttribute("cui-anchorid", this.#defaultListButton.id);
-@@ -7995,6 +7998,7 @@ class OverflowableToolbar {
+@@ -8000,6 +7998,7 @@ class OverflowableToolbar {
       return aElement.getBoundingClientRect().width;
     }
@@ -171,7 +173,7 @@ index 6d1885a54815d10b3a4e79f7e5acd61ab3abb159..3d6e092e7ed126cdee8c32229df2cfa1
     function sumChildrenInlineSize(aParent, aExceptChild = null) {
       let sum = 0;
       for (let child of aParent.children) {
-@@ -8006,7 +8010,10 @@ class OverflowableToolbar {
+@@ -8011,7 +8010,10 @@ class OverflowableToolbar {
         ) {
           continue;
         }
@@ -183,7 +185,7 @@ index 6d1885a54815d10b3a4e79f7e5acd61ab3abb159..3d6e092e7ed126cdee8c32229df2cfa1
         if (child != aExceptChild) {
           sum += getInlineSize(child);
         }
-@@ -8030,11 +8037,11 @@ class OverflowableToolbar {
+@@ -8035,11 +8037,11 @@ class OverflowableToolbar {
         parseFloat(style.paddingLeft) -
         parseFloat(style.paddingRight) -
         toolbarChildrenWidth;
@@ -197,7 +199,7 @@ index 6d1885a54815d10b3a4e79f7e5acd61ab3abb159..3d6e092e7ed126cdee8c32229df2cfa1
     });
     lazy.log.debug(
-@@ -8049,7 +8056,39 @@ class OverflowableToolbar {
+@@ -8054,7 +8056,39 @@ class OverflowableToolbar {
       Math.max(targetWidth, targetChildrenWidth)
     );
     totalAvailWidth = Math.ceil(totalAvailWidth);
@@ -238,7 +240,7 @@ index 6d1885a54815d10b3a4e79f7e5acd61ab3abb159..3d6e092e7ed126cdee8c32229df2cfa1
     return { isOverflowing, targetContentWidth, totalAvailWidth };
   }
-@@ -8110,7 +8149,11 @@ class OverflowableToolbar {
+@@ -8115,7 +8149,11 @@ class OverflowableToolbar {
             return;
           }
         }
@@ -251,7 +253,7 @@ index 6d1885a54815d10b3a4e79f7e5acd61ab3abb159..3d6e092e7ed126cdee8c32229df2cfa1
           lazy.log.debug(
             `Need ${minSize} but width is ${totalAvailWidth} so bailing`
           );
-@@ -8143,7 +8186,7 @@ class OverflowableToolbar {
+@@ -8148,7 +8186,7 @@ class OverflowableToolbar {
         }
       }
       if (!inserted) {
@@ -260,7 +262,7 @@ index 6d1885a54815d10b3a4e79f7e5acd61ab3abb159..3d6e092e7ed126cdee8c32229df2cfa1
       }
       child.removeAttribute("cui-anchorid");
       child.removeAttribute("overflowedItem");
-@@ -8269,6 +8312,9 @@ class OverflowableToolbar {
+@@ -8274,6 +8312,9 @@ class OverflowableToolbar {
    *   if no such list exists.
    */
   get #webExtList() {
@@ -270,7 +272,7 @@ index 6d1885a54815d10b3a4e79f7e5acd61ab3abb159..3d6e092e7ed126cdee8c32229df2cfa1
     if (!this.#webExtListRef) {
       let targetID = this.#toolbar.getAttribute("addon-webext-overflowtarget");
       if (!targetID) {
-@@ -8280,6 +8326,9 @@ class OverflowableToolbar {
+@@ -8285,6 +8326,9 @@ class OverflowableToolbar {
       let win = this.#toolbar.documentGlobal;
       let { panel } = win.gUnifiedExtensions;
       this.#webExtListRef = panel.querySelector(`#${targetID}`);
@@ -280,7 +282,7 @@ index 6d1885a54815d10b3a4e79f7e5acd61ab3abb159..3d6e092e7ed126cdee8c32229df2cfa1
     }
     return this.#webExtListRef;
   }
-@@ -8488,7 +8537,7 @@ class OverflowableToolbar {
+@@ -8493,7 +8537,7 @@ class OverflowableToolbar {
         break;
       }
       case "mousedown": {
@@ -1,16 +1,17 @@
 diff --git a/browser/components/preferences/config/account-sync.mjs b/browser/components/preferences/config/account-sync.mjs
-index b01fd4bb163ad53139fcbd8e79e12ef994d1fa13..dd60be4fe268618d6596cd5cfac3342975bd241a 100644
+index b01fd4bb163ad53139fcbd8e79e12ef994d1fa13..7e3c2f6852b77192b4505bb3d5a7b58586da6548 100644
 --- a/browser/components/preferences/config/account-sync.mjs
 +++ b/browser/components/preferences/config/account-sync.mjs
-@@ -46,6 +46,7 @@ Preferences.addAll([
+@@ -46,6 +46,8 @@ Preferences.addAll([
   { id: "services.sync.engine.creditcards", type: "bool" },
   { id: "services.sync.engine.addons", type: "bool" },
   { id: "services.sync.engine.prefs", type: "bool" },
 +  { id: "services.sync.engine.spaces", type: "bool" },
 +  { id: "zen.spaces-sync.normal-tabs", type: "bool" },
 ]);
 /**
-@@ -557,6 +558,7 @@ const SYNC_ENGINE_SETTINGS = [
+@@ -557,6 +559,7 @@ const SYNC_ENGINE_SETTINGS = [
     type: "payments",
   },
   { id: "syncAddons", pref: "services.sync.engine.addons", type: "addons" },
@@ -18,7 +19,7 @@ index b01fd4bb163ad53139fcbd8e79e12ef994d1fa13..dd60be4fe268618d6596cd5cfac33429
   { id: "syncSettings", pref: "services.sync.engine.prefs", type: "settings" },
 ];
-@@ -564,6 +566,12 @@ SYNC_ENGINE_SETTINGS.forEach(({ id, pref }) => {
+@@ -564,6 +567,18 @@ SYNC_ENGINE_SETTINGS.forEach(({ id, pref }) => {
   Preferences.addSetting({ id, pref });
 });
@@ -27,11 +28,17 @@ index b01fd4bb163ad53139fcbd8e79e12ef994d1fa13..dd60be4fe268618d6596cd5cfac33429
 +  id: "zenSyncWorkspaces",
 +  pref: "services.sync.engine.spaces",
 +});
 +Preferences.addSetting({
 +  id: "zenSyncNormalTabs",
 +  pref: "zen.spaces-sync.normal-tabs",
 +  deps: ["zenSyncWorkspaces"],
 +  visible: deps => !!deps.zenSyncWorkspaces.value,
 +});
 +
 Preferences.addSetting({
   id: "syncEngines",
   deps: SYNC_ENGINE_SETTINGS.map(({ id }) => id),
-@@ -995,6 +1003,20 @@ SettingGroupManager.registerGroups({
+@@ -995,6 +1010,27 @@ SettingGroupManager.registerGroups({
             id: "syncEnginesList",
             control: "sync-engines-list",
           },
@@ -46,6 +53,13 @@ index b01fd4bb163ad53139fcbd8e79e12ef994d1fa13..dd60be4fe268618d6596cd5cfac33429
 +                controlAttrs: {
 +                  inputlayout: "inline-end",
 +                },
 +                items: [
 +                  {
 +                    id: "zenSyncNormalTabs",
 +                    l10nId: "zen-settings-normal-tabs-sync",
 +                    control: "moz-checkbox",
 +                  },
 +                ],
 +              },
 +            ],
 +          },
@@ -1,8 +1,8 @@
 diff --git a/browser/components/preferences/main.js b/browser/components/preferences/main.js
-index 88675d1bcbf000b10d85a9c0980bc6069d88052c..ed3a1e809eb0fcccc5a957be7affb77be8978e32 100644
+index 5a56d348146c1c37c088ced60327fffebcf8fac0..abd65594d365fbc0a74af3953c71f410301898ad 100644
 --- a/browser/components/preferences/main.js
 +++ b/browser/components/preferences/main.js
-@@ -528,6 +528,11 @@ function createStartupConfig(hidden = false) {
+@@ -529,6 +529,11 @@ function createStartupConfig(hidden = false) {
           },
         ],
       },
@@ -14,7 +14,7 @@ index 88675d1bcbf000b10d85a9c0980bc6069d88052c..ed3a1e809eb0fcccc5a957be7affb77b
       {
         id: "windowsLaunchOnLogin",
         l10nId: "windows-launch-on-login",
-@@ -575,7 +580,7 @@ function createStartupConfig(hidden = false) {
+@@ -576,7 +581,7 @@ function createStartupConfig(hidden = false) {
 SettingGroupManager.registerGroups({
   defaultBrowser: createDefaultBrowserConfig(),
   startup: createStartupConfig(
@@ -23,7 +23,7 @@ index 88675d1bcbf000b10d85a9c0980bc6069d88052c..ed3a1e809eb0fcccc5a957be7affb77b
   ),
 });
-@@ -628,7 +633,7 @@ function getBundleForLocales(newLocales) {
+@@ -636,7 +641,7 @@ function getBundleForLocales(newLocales) {
     ])
   );
   return new Localization(
@@ -38,9 +38,16 @@ var gZenMarketplaceManager = {
    this.__hasInitializedEvents = true;
    await this._buildModsList();
    Services.prefs.addObserver(gZenMods.updatePref, this);
    window.addEventListener(
      "unload",
      () => {
        Services.prefs.removeObserver(gZenMods.updatePref, this);
      },
      { once: true }
    );
    await this._buildModsList();
    const checkForUpdateClick = (event) => {
      if (event.target === checkForUpdates) {
@@ -69,7 +76,6 @@ var gZenMarketplaceManager = {
    });
    window.addEventListener("unload", () => {
      Services.prefs.removeObserver(gZenMods.updatePref, this);
      this.__hasInitializedEvents = false;
      document.removeEventListener("ZenModsMarketplace:CheckForUpdatesFinished", this);
@@ -735,7 +741,6 @@ var gZenWorkspacesSettings = {
    Services.prefs.addObserver("zen.glance.enabled", tabsUnloaderPrefListener); // We can use the same listener for both prefs
    Services.prefs.addObserver("zen.workspaces.separate-essentials", tabsUnloaderPrefListener);
    Services.prefs.addObserver("zen.glance.activation-method", tabsUnloaderPrefListener);
    Services.prefs.addObserver("zen.window-sync.sync-only-pinned-tabs", tabsUnloaderPrefListener);
    Services.prefs.addObserver(
      "zen.tabs.ctrl-tab.ignore-essential-tabs",
@@ -744,7 +749,6 @@ var gZenWorkspacesSettings = {
    Services.prefs.addObserver("browser.ctrlTab.sortByRecentlyUsed", toggleZenCycleByAttrWarning);
    window.addEventListener("unload", () => {
      Services.prefs.removeObserver("zen.glance.enabled", tabsUnloaderPrefListener);
      Services.prefs.removeObserver("zen.glance.activation-method", tabsUnloaderPrefListener);
      Services.prefs.removeObserver("zen.workspaces.separate-essentials", tabsUnloaderPrefListener);
      Services.prefs.removeObserver(
        "zen.window-sync.sync-only-pinned-tabs",
@@ -1,16 +1,16 @@
 diff --git a/browser/components/sessionstore/SessionFile.sys.mjs b/browser/components/sessionstore/SessionFile.sys.mjs
-index 5580838acd72bf0e1189d367984859529d89f5b4..e5fa6076a9cc6ada016ccc4e129cad455010a522 100644
+index 370e5c105c3d9bee05c2d9d7b63d0ee45b8331e1..1c37c19794ebe863a25f780e9a74d63526b929d7 100644
 --- a/browser/components/sessionstore/SessionFile.sys.mjs
 +++ b/browser/components/sessionstore/SessionFile.sys.mjs
-@@ -22,6 +22,7 @@ ChromeUtils.defineESModuleGetters(lazy, {
+@@ -25,6 +25,7 @@ const lazy = XPCOMUtils.declareLazy({
-   RunState: "resource:///modules/sessionstore/RunState.sys.mjs",
+     "moz-src:///browser/components/sessionstore/SessionStore.sys.mjs",
-   SessionStore: "resource:///modules/sessionstore/SessionStore.sys.mjs",
+   SessionWriter:
-   SessionWriter: "resource:///modules/sessionstore/SessionWriter.sys.mjs",
+     "moz-src:///browser/components/sessionstore/SessionWriter.sys.mjs",
 +  ZenSessionStore: "resource:///modules/zen/ZenSessionManager.sys.mjs",
 });
 const PREF_UPGRADE_BACKUP = "browser.sessionstore.upgradeBackup.latestBuildID";
-@@ -381,7 +382,7 @@ var SessionFileInternal = {
+@@ -384,7 +385,7 @@ var SessionFileInternal = {
     this._readOrigin = result.origin;
     result.noFilesFound = noFilesFound;
@@ -1,11 +1,11 @@
 diff --git a/browser/components/sessionstore/SessionSaver.sys.mjs b/browser/components/sessionstore/SessionSaver.sys.mjs
-index 9141793550f7c7ff6aa63d4c85bf571b4499e2d0..6906fd9be7ae6ca4316133e0d6552b797c54a7ec 100644
+index 1f26bc5fdb83f55bdf0b9b7d01fafe1cd37f77f4..5916f741d0fa04c392dcdd10f843e595fe5e058c 100644
 --- a/browser/components/sessionstore/SessionSaver.sys.mjs
 +++ b/browser/components/sessionstore/SessionSaver.sys.mjs
-@@ -20,6 +20,7 @@ ChromeUtils.defineESModuleGetters(lazy, {
+@@ -20,6 +20,7 @@ const lazy = XPCOMUtils.declareLazy({
-   SessionFile: "resource:///modules/sessionstore/SessionFile.sys.mjs",
+     "moz-src:///browser/components/sessionstore/SessionStore.sys.mjs",
-   SessionStore: "resource:///modules/sessionstore/SessionStore.sys.mjs",
+   sessionStoreLogger:
-   sessionStoreLogger: "resource:///modules/sessionstore/SessionLogger.sys.mjs",
+     "moz-src:///browser/components/sessionstore/SessionLogger.sys.mjs",
 +  ZenSessionStore: "resource:///modules/zen/ZenSessionManager.sys.mjs",
 });
@@ -1,16 +1,16 @@
 diff --git a/browser/components/sessionstore/SessionStartup.sys.mjs b/browser/components/sessionstore/SessionStartup.sys.mjs
-index 86600ffb5178599ab23270a964064ca657a3283f..70d7b5c7d69d3700475d663b595052264c67d351 100644
+index 919d4536c5462603346684bbe26794ae9279b517..5a8fae0708e4a9a82c5e85f8a473ebaeafebe71f 100644
 --- a/browser/components/sessionstore/SessionStartup.sys.mjs
 +++ b/browser/components/sessionstore/SessionStartup.sys.mjs
-@@ -40,6 +40,7 @@ ChromeUtils.defineESModuleGetters(lazy, {
+@@ -41,6 +41,7 @@ const lazy = XPCOMUtils.declareLazy({
-   StartupPerformance:
+     "moz-src:///browser/components/sessionstore/StartupPerformance.sys.mjs",
-     "resource:///modules/sessionstore/StartupPerformance.sys.mjs",
+   sessionStoreLogger:
-   sessionStoreLogger: "resource:///modules/sessionstore/SessionLogger.sys.mjs",
+     "moz-src:///browser/components/sessionstore/SessionLogger.sys.mjs",
 +  ZenSessionStore: "resource:///modules/zen/ZenSessionManager.sys.mjs",
 });
 const STATE_RUNNING_STR = "running";
-@@ -85,7 +86,7 @@ export var SessionStartup = {
+@@ -86,7 +87,7 @@ export var SessionStartup = {
     }
     // do not need to initialize anything in auto-started private browsing sessions
@@ -19,7 +19,7 @@ index 86600ffb5178599ab23270a964064ca657a3283f..70d7b5c7d69d3700475d663b59505226
       this._initialized = true;
       gOnceInitializedDeferred.resolve();
       return;
-@@ -179,6 +180,8 @@ export var SessionStartup = {
+@@ -180,6 +181,8 @@ export var SessionStartup = {
       this._initialState = parsed;
     }
@@ -28,7 +28,7 @@ index 86600ffb5178599ab23270a964064ca657a3283f..70d7b5c7d69d3700475d663b59505226
     if (this._initialState == null) {
       // No valid session found.
       this._sessionType = this.NO_SESSION;
-@@ -276,6 +279,8 @@ export var SessionStartup = {
+@@ -277,6 +280,8 @@ export var SessionStartup = {
         `Previous shutdown ok? ${this._previousSessionCrashed}, reason: ${previousSessionCrashedReason}`
       );
@@ -37,7 +37,7 @@ index 86600ffb5178599ab23270a964064ca657a3283f..70d7b5c7d69d3700475d663b59505226
       Services.obs.addObserver(this, "sessionstore-windows-restored", true);
       if (this.sessionType == this.NO_SESSION) {
-@@ -336,12 +341,7 @@ export var SessionStartup = {
+@@ -337,12 +342,7 @@ export var SessionStartup = {
   isAutomaticRestoreEnabled() {
     if (this._resumeSessionEnabled === null) {
       this._resumeSessionEnabled =
@@ -51,7 +51,7 @@ index 86600ffb5178599ab23270a964064ca657a3283f..70d7b5c7d69d3700475d663b59505226
     }
     return this._resumeSessionEnabled;
-@@ -354,8 +354,7 @@ export var SessionStartup = {
+@@ -355,8 +355,7 @@ export var SessionStartup = {
    */
   willRestore() {
     return (
@@ -1,8 +1,8 @@
 diff --git a/browser/components/sessionstore/SessionStore.sys.mjs b/browser/components/sessionstore/SessionStore.sys.mjs
-index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2ab6e6c967 100644
+index 52fc803050cd257d6de52b1e4a92f3211cbaba88..a9841832ddce540dc0f9b14c29e5eadac7510935 100644
 --- a/browser/components/sessionstore/SessionStore.sys.mjs
 +++ b/browser/components/sessionstore/SessionStore.sys.mjs
-@@ -129,6 +129,11 @@ const TAB_EVENTS = [
+@@ -111,6 +111,11 @@ const TAB_EVENTS = [
   "TabSplitViewActivate",
   "SplitViewRemoved",
   "SplitViewCreated",
@@ -14,16 +14,39 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
 ];
 const XUL_NS = "http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul";
-@@ -201,6 +206,8 @@ ChromeUtils.defineESModuleGetters(lazy, {
+@@ -185,6 +190,8 @@ const lazy = XPCOMUtils.declareLazy({
-   TabStateCache: "resource:///modules/sessionstore/TabStateCache.sys.mjs",
+   TabStateFlusher:
-   TabStateFlusher: "resource:///modules/sessionstore/TabStateFlusher.sys.mjs",
+     "moz-src:///browser/components/sessionstore/TabStateFlusher.sys.mjs",
   setTimeout: "resource://gre/modules/Timer.sys.mjs",
 +  ZenSessionStore: "resource:///modules/zen/ZenSessionManager.sys.mjs",
 +  ZenWindowSync: "resource:///modules/zen/ZenWindowSync.sys.mjs",
- });
+   blankURI: () => Services.io.newURI("about:blank"),
   gRestoreWindowsToVirtualDesktop: {
     pref: "browser.sessionstore.restore_windows_to_virtual_desktop",
@@ -348,6 +355,22 @@ class _SessionStore {
     return this.#shouldRestoreLastSession;
   }
- ChromeUtils.defineLazyGetter(lazy, "blankURI", () => {
+  get _windows() {
-@@ -1317,10 +1324,7 @@ var SessionStoreInternal = {
+    return this.#windows;
 +  }
 +
 +  get _browserWindows() {
 +    return this.#browserWindows;
 +  }
 +
 +  set _deferredInitialState(aState) {
 +    this.#deferredInitialState = aState;
 +  }
 +
 +  initializeWindow(aWindow, aInitialState) {
 +    this.#initializeWindow(aWindow, aInitialState);
 +  }
 +
   // whether we will potentially be restoring the session
   // more than once without Firefox restarting in between
   #restoreWithoutRestart = false;
@@ -515,10 +538,7 @@ class _SessionStore {
    */
   get willAutoRestore() {
     return (
@@ -33,9 +56,9 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
 -          BROWSER_STARTUP_RESUME_SESSION)
 +      true
     );
-   },
+   }
-@@ -2008,6 +2012,11 @@ var SessionStoreInternal = {
+@@ -1215,6 +1235,11 @@ class _SessionStore {
       case "TabPinned":
       case "TabUnpinned":
       case "SwapDocShells":
@@ -44,47 +67,47 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
 +      case "TabMove":
 +      case "TabGroupMoved":
 +      case "ZenWorkspaceDataChanged":
-         this.saveStateDelayed(win);
+         this.#saveStateDelayed(win);
         break;
       case "TabGroupCreate":
-@@ -2117,6 +2126,10 @@ var SessionStoreInternal = {
+@@ -1341,6 +1366,10 @@ class _SessionStore {
-       this._windows[aWindow.__SSi].isTaskbarTab = true;
+       this.#windows[aWindow.__SSi].isTaskbarTab = true;
     }
 +    if (aWindow.document.documentElement.hasAttribute("zen-unsynced-window")) {
-+      this._windows[aWindow.__SSi].isZenUnsynced = true;
+      this.#windows[aWindow.__SSi].isZenUnsynced = true;
 +    }
 +
     if (lazy.AIWindow.isAIWindowActiveAndEnabled(aWindow)) {
-       this._windows[aWindow.__SSi].isAIWindow = true;
+       this.#windows[aWindow.__SSi].isAIWindow = true;
     }
-@@ -2153,7 +2166,7 @@ var SessionStoreInternal = {
+@@ -1377,7 +1406,7 @@ class _SessionStore {
-     let isTaskbarTab = this._windows[aWindow.__SSi].isTaskbarTab;
+     let isTaskbarTab = this.#windows[aWindow.__SSi].isTaskbarTab;
     // A regular window is not a private window, taskbar tab window, or popup window
     let isRegularWindow =
 -      !isPrivateWindow && !isTaskbarTab && aWindow.toolbar.visible;
-+      !isPrivateWindow && !isTaskbarTab && aWindow.toolbar.visible && !this._windows[aWindow.__SSi].isZenUnsynced;
+      !isPrivateWindow && !isTaskbarTab && aWindow.toolbar.visible && !this.#windows[aWindow.__SSi].isZenUnsynced;
     // perform additional initialization when the first window is loading
     if (lazy.RunState.isStopped) {
-@@ -2165,7 +2178,7 @@ var SessionStoreInternal = {
+@@ -1389,7 +1418,7 @@ class _SessionStore {
         // to disk to NOW() to enforce a full interval before the next write.
         lazy.SessionSaver.updateLastSaveTime();
 -        if (isPrivateWindow || isTaskbarTab) {
 +        if (isPrivateWindow || isTaskbarTab || aWindow.document.documentElement.hasAttribute("zen-unsynced-window")) {
-           this._log.debug(
+           this.#log.debug(
             "initializeWindow, the window is private or a web app. Saving SessionStartup.state for possibly restoring later"
           );
-@@ -2209,6 +2222,7 @@ var SessionStoreInternal = {
+@@ -1433,6 +1462,7 @@ class _SessionStore {
           null,
           "sessionstore-one-or-no-tab-restored"
         );
 +        lazy.ZenSessionStore.onNewEmptySession(aWindow);
-         this._deferredAllWindowsRestored.resolve();
+         this.#deferredAllWindowsRestored.resolve();
       }
-       // this window was opened by _openWindowWithState
+       // this window was opened by #openWindowWithState
-@@ -2258,7 +2272,6 @@ var SessionStoreInternal = {
+@@ -1482,7 +1512,6 @@ class _SessionStore {
       if (closedWindowState) {
         let newWindowState;
         if (
@@ -92,25 +115,25 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
           !lazy.SessionStartup.willRestore()
         ) {
           // We want to split the window up into pinned tabs and unpinned tabs.
-@@ -2294,6 +2307,7 @@ var SessionStoreInternal = {
+@@ -1518,6 +1547,7 @@ class _SessionStore {
         }
         if (newWindowState) {
 +          lazy.ZenSessionStore.onRestoringClosedWindow(newWindowState);
           // Ensure that the window state isn't hidden
-           this._restoreCount = 1;
+           this.#restoreCount = 1;
           let state = { windows: [newWindowState] };
-@@ -2330,6 +2344,9 @@ var SessionStoreInternal = {
+@@ -1554,6 +1584,9 @@ class _SessionStore {
       });
-       this._shouldRestoreLastSession = false;
+       this.#shouldRestoreLastSession = false;
     }
 +    else if (!aInitialState && isRegularWindow) {
 +      lazy.ZenSessionStore.restoreNewWindow(aWindow, this);
 +    }
-     if (this._restoreLastWindow && aWindow.toolbar.visible) {
+     if (this.#restoreLastWindow && aWindow.toolbar.visible) {
       // always reset (if not a popup window)
-@@ -2480,7 +2497,7 @@ var SessionStoreInternal = {
+@@ -1704,7 +1737,7 @@ class _SessionStore {
     var tabbrowser = aWindow.gBrowser;
@@ -119,56 +142,56 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
     TAB_EVENTS.forEach(function (aEvent) {
       tabbrowser.tabContainer.removeEventListener(aEvent, this, true);
-@@ -2531,7 +2548,7 @@ var SessionStoreInternal = {
+@@ -1755,7 +1788,7 @@ class _SessionStore {
       let isLastRegularWindow =
-         Object.values(this._windows).filter(
+         Object.values(this.#windows).filter(
 -          wData => !wData.isPrivate && !wData.isTaskbarTab
 +          wData => !wData.isPrivate && !wData.isTaskbarTab && !wData.isZenUnsynced
         ).length == 1;
-       this._log.debug(
+       this.#log.debug(
         `onClose, closing window isLastRegularWindow? ${isLastRegularWindow}`
-@@ -2588,8 +2605,8 @@ var SessionStoreInternal = {
+@@ -1812,8 +1845,8 @@ class _SessionStore {
       // 2) Flush the window.
       // 3) When the flush is complete, revisit our decision to store the window
-       //    in _closedWindows, and add/remove as necessary.
+       //    in #closedWindows, and add/remove as necessary.
 -      if (!winData.isPrivate && !winData.isTaskbarTab) {
-        this.maybeSaveClosedWindow(winData, isLastWindow);
+-        this.#maybeSaveClosedWindow(winData, isLastWindow);
 +      if (!winData.isPrivate && !winData.isTaskbarTab && !winData.isZenUnsynced) {
-+        this.maybeSaveClosedWindow(winData, isLastWindow, isLastRegularWindow);
+        this.#maybeSaveClosedWindow(winData, isLastWindow, isLastRegularWindow);
       }
       completionPromise = lazy.TabStateFlusher.flushWindow(aWindow).then(() => {
-@@ -2609,8 +2626,9 @@ var SessionStoreInternal = {
+@@ -1833,8 +1866,9 @@ class _SessionStore {
         // Save non-private windows if they have at
         // least one saveable tab or are the last window.
 -        if (!winData.isPrivate && !winData.isTaskbarTab) {
-          this.maybeSaveClosedWindow(winData, isLastWindow);
+-          this.#maybeSaveClosedWindow(winData, isLastWindow);
 +        lazy.ZenWindowSync.on_WindowCloseAndBrowserFlushed(browsers);
 +        if (!winData.isPrivate && !winData.isTaskbarTab && !winData.isZenUnsynced) {
-+          this.maybeSaveClosedWindow(winData, isLastWindow, isLastRegularWindow);
+          this.#maybeSaveClosedWindow(winData, isLastWindow, isLastRegularWindow);
           if (!isLastWindow && winData.closedId > -1) {
-             this._addClosedAction(
+             this.#addClosedAction(
-@@ -2686,7 +2704,7 @@ var SessionStoreInternal = {
+@@ -1910,7 +1944,7 @@ class _SessionStore {
    *        to call this method again asynchronously (for example, after
    *        a window flush).
    */
-  maybeSaveClosedWindow(winData, isLastWindow) {
+-  #maybeSaveClosedWindow(winData, isLastWindow) {
-+  maybeSaveClosedWindow(winData, isLastWindow, isLastRegularWindow = false) {
+  #maybeSaveClosedWindow(winData, isLastWindow, isLastRegularWindow = false) {
     // Make sure SessionStore is still running, and make sure that we
     // haven't chosen to forget this window.
     if (
-@@ -2703,6 +2721,7 @@ var SessionStoreInternal = {
+@@ -1927,6 +1961,7 @@ class _SessionStore {
-       // _closedWindows from a previous call to this function.
+       // #closedWindows from a previous call to this function.
-       let winIndex = this._closedWindows.indexOf(winData);
+       let winIndex = this.#closedWindows.indexOf(winData);
       let alreadyStored = winIndex != -1;
 +      lazy.ZenSessionStore.maybeSaveClosedWindow(winData, isLastRegularWindow);
       // If sidebar command is truthy, i.e. sidebar is open, store sidebar settings
       let shouldStore = hasSaveableTabs || isLastWindow;
-@@ -3525,7 +3544,7 @@ var SessionStoreInternal = {
+@@ -2744,7 +2779,7 @@ class _SessionStore {
     if (!isPrivateWindow && tabState.isPrivate) {
       return;
     }
@@ -177,10 +200,14 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
       return;
     }
-@@ -4264,6 +4283,12 @@ var SessionStoreInternal = {
+@@ -3511,7 +3546,15 @@ class _SessionStore {
         1,
         Math.min(tabState.index, tabState.entries.length)
       );
-       tabState.pinned = false;
+-      tabState.pinned = false;
 +      tabState.pinned =
 +        newTab.group?.isZenFolder === true &&
 +        Services.prefs.getBoolPref("zen.folders.owned-tabs-in-folder");
 +      tabState.zenEssential = false;
 +      tabState.zenSyncId = null;
 +      tabState.zenIsGlance = false;
@@ -190,7 +217,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
       if (inBackground === false) {
         aWindow.gBrowser.selectedTab = newTab;
-@@ -4697,6 +4722,8 @@ var SessionStoreInternal = {
+@@ -4036,6 +4079,8 @@ class _SessionStore {
       // Append the tab if we're opening into a different window,
       tabIndex: aSource == aTargetWindow ? pos : Infinity,
       pinned: state.pinned,
@@ -199,7 +226,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
       userContextId: state.userContextId,
       skipLoad: true,
       preferredRemoteType,
-@@ -5194,9 +5221,10 @@ var SessionStoreInternal = {
+@@ -4608,9 +4653,10 @@ class _SessionStore {
       if (activePageData.title && activePageData.title != activePageData.url) {
         win.gBrowser.setInitialTabTitle(tab, activePageData.title, {
           isContentTitle: true,
@@ -211,7 +238,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
       }
     }
-@@ -5561,7 +5589,7 @@ var SessionStoreInternal = {
+@@ -4982,7 +5028,7 @@ class _SessionStore {
     for (let i = tabbrowser.pinnedTabCount; i < tabbrowser.tabs.length; i++) {
       let tab = tabbrowser.tabs[i];
@@ -220,30 +247,30 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
         removableTabs.push(tab);
       }
     }
-@@ -5674,7 +5702,7 @@ var SessionStoreInternal = {
+@@ -5095,7 +5141,7 @@ class _SessionStore {
     // collect the data for all windows
-     for (ix in this._windows) {
+     for (ix in this.#windows) {
-      if (this._windows[ix]._restoring || this._windows[ix].isTaskbarTab) {
+-      if (this.#windows[ix]._restoring || this.#windows[ix].isTaskbarTab) {
-+      if (this._windows[ix]._restoring || this._windows[ix].isTaskbarTab && !this._windows[ix].isZenUnsynced) {
+      if (this.#windows[ix]._restoring || this.#windows[ix].isTaskbarTab && !this.#windows[ix].isZenUnsynced) {
-         // window data is still in _statesToRestore
+         // window data is still in #statesToRestore
         continue;
       }
-@@ -5818,11 +5846,12 @@ var SessionStoreInternal = {
+@@ -5239,11 +5285,12 @@ class _SessionStore {
     }
     let tabbrowser = aWindow.gBrowser;
 -    let tabs = tabbrowser.tabs;
 +    let tabs = aWindow.gZenWorkspaces.allStoredTabs;
     /** @type {WindowStateData} */
-     let winData = this._windows[aWindow.__SSi];
+     let winData = this.#windows[aWindow.__SSi];
     let tabsData = (winData.tabs = []);
 +    winData.splitViewData = aWindow.gZenViewSplitter?.storeDataForSessionStore();
     // update the internal state data for this window
     for (let tab of tabs) {
       if (tab == aWindow.FirefoxViewHandler.tab) {
-@@ -5833,6 +5862,9 @@ var SessionStoreInternal = {
+@@ -5254,6 +5301,9 @@ class _SessionStore {
       tabsData.push(tabData);
     }
@@ -253,7 +280,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
     // update tab group state for this window
     winData.groups = [];
     for (let tabGroup of aWindow.gBrowser.tabGroups) {
-@@ -5849,7 +5881,7 @@ var SessionStoreInternal = {
+@@ -5270,7 +5320,7 @@ class _SessionStore {
     // a window is closed, point to the first item in the tab strip instead (it will never be the Firefox View tab,
     // since it's only inserted into the tab strip after it's selected).
     if (aWindow.FirefoxViewHandler.tab?.selected) {
@@ -262,7 +289,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
       winData.title = tabbrowser.tabs[0].label;
     }
     winData.selected = selectedIndex;
-@@ -6051,8 +6083,8 @@ var SessionStoreInternal = {
+@@ -5472,8 +5522,8 @@ class _SessionStore {
     // selectTab represents.
     let selectTab = 0;
     if (overwriteTabs) {
@@ -273,7 +300,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
       selectTab = Math.min(selectTab, winData.tabs.length);
     }
-@@ -6074,6 +6106,7 @@ var SessionStoreInternal = {
+@@ -5495,6 +5545,7 @@ class _SessionStore {
     if (overwriteTabs) {
       for (let i = tabbrowser.browsers.length - 1; i >= 0; i--) {
         if (!tabbrowser.tabs[i].selected) {
@@ -281,7 +308,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
           tabbrowser.removeTab(tabbrowser.tabs[i]);
         }
       }
-@@ -6108,6 +6141,12 @@ var SessionStoreInternal = {
+@@ -5529,6 +5580,12 @@ class _SessionStore {
         savedTabGroup => !openTabGroupIdsInWindow.has(savedTabGroup.id)
       );
     }
@@ -294,7 +321,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
     // Move the originally open tabs to the end.
     if (initialTabs) {
-@@ -6674,6 +6713,25 @@ var SessionStoreInternal = {
+@@ -6098,6 +6155,25 @@ class _SessionStore {
     // Most of tabData has been restored, now continue with restoring
     // attributes that may trigger external events.
@@ -320,17 +347,25 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
     if (tabData.pinned) {
       tabbrowser.pinTab(tab);
-@@ -6859,6 +6917,9 @@ var SessionStoreInternal = {
+@@ -6272,6 +6348,9 @@ class _SessionStore {
         aWindow.gURLBar.readOnly = false;
       }
     }
 +    if (aWinData.isZenUnsynced) {
-+      this._windows[aWindow.__SSi].isZenUnsynced = true;
+      this.#windows[aWindow.__SSi].isZenUnsynced = true;
 +    }
     let promiseParts = Promise.withResolvers();
-     aWindow.setTimeout(() => {
+     const wasMinimized = aWindow.windowState == aWindow.STATE_MINIMIZED;
-@@ -7654,7 +7715,7 @@ var SessionStoreInternal = {
+@@ -6774,6 +6853,7 @@ class _SessionStore {
    */
   #isCmdLineEmpty(aWindow, aState) {
     var pinnedOnly =
 +      !Services.prefs.getBoolPref("zen.workspaces.continue-where-left-off") &&
       aState.windows &&
       aState.windows.every(win => win.tabs.every(tab => tab.pinned));
@@ -7116,7 +7196,7 @@ class _SessionStore {
       let groupsToSave = new Map();
       for (let tIndex = 0; tIndex < window.tabs.length; ) {
@@ -339,7 +374,7 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
           // Adjust window.selected
           if (tIndex + 1 < window.selected) {
             window.selected -= 1;
-@@ -7669,7 +7730,7 @@ var SessionStoreInternal = {
+@@ -7131,7 +7211,7 @@ class _SessionStore {
           );
           // We don't want to increment tIndex here.
           continue;
@@ -348,15 +383,15 @@ index 536e06eec9f35bad3b8366733b23b5a8697df9c8..631a16bc7518108641993836f0c52e2a
           // Convert any open groups into saved groups.
           let groupStateToSave = window.groups.find(
             groupState => groupState.id == window.tabs[tIndex].groupId
-@@ -8233,7 +8294,6 @@ var SessionStoreInternal = {
+@@ -7691,7 +7771,6 @@ class _SessionStore {
     timer.initWithCallback(
-       function () {
+       () => {
         if (beats <= 0) {
-          this._log.debug(`looseTimer of ${delay} timed out`);
+-          this.#log.debug(`looseTimer of ${delay} timed out`);
           Glean.sessionRestore.shutdownFlushAllOutcomes.timed_out.add(1);
           deferred.resolve();
         }
-@@ -8711,6 +8771,7 @@ var SessionStoreInternal = {
+@@ -8174,6 +8253,7 @@ class _SessionStore {
     if (
       !savedTabGroupState.tabs.length ||
       this.getSavedTabGroup(savedTabGroupState.id)
@@ -1,16 +1,16 @@
 diff --git a/browser/components/sessionstore/TabState.sys.mjs b/browser/components/sessionstore/TabState.sys.mjs
-index a33deeb5b587d6a950960a1a4781176e4e730ad7..e96cfb9a5ffbe4feccdffa8b6d18ececb48d4c52 100644
+index bb7bd8c7ca88f776188fce64e0c85beb5ceb27a5..bdec77ba26172fe1b41369b1d45d5a6f9d52ae25 100644
 --- a/browser/components/sessionstore/TabState.sys.mjs
 +++ b/browser/components/sessionstore/TabState.sys.mjs
-@@ -8,6 +8,7 @@ ChromeUtils.defineESModuleGetters(lazy, {
+@@ -10,6 +10,7 @@ const lazy = XPCOMUtils.declareLazy({
-   PrivacyFilter: "resource://gre/modules/sessionstore/PrivacyFilter.sys.mjs",
+     "moz-src:///browser/components/sessionstore/TabAttributes.sys.mjs",
-   TabAttributes: "resource:///modules/sessionstore/TabAttributes.sys.mjs",
+   TabStateCache:
-   TabStateCache: "resource:///modules/sessionstore/TabStateCache.sys.mjs",
+     "moz-src:///browser/components/sessionstore/TabStateCache.sys.mjs",
 +  UrlbarShared: "chrome://browser/content/urlbar/UrlbarShared.mjs",
-   sessionStoreLogger: "resource:///modules/sessionstore/SessionLogger.sys.mjs",
+   sessionStoreLogger:
     "moz-src:///browser/components/sessionstore/SessionLogger.sys.mjs",
 });
- 
+@@ -106,10 +107,28 @@ class _TabState {
@@ -103,10 +104,28 @@ class _TabState {
       }
     }
@@ -39,3 +39,14 @@ index a33deeb5b587d6a950960a1a4781176e4e730ad7..e96cfb9a5ffbe4feccdffa8b6d18ecec
     tabData.userContextId = tab.userContextId || 0;
@@ -135,6 +154,10 @@ class _TabState {
       tabData.image = tabbrowser.getIcon(tab);
     }
 +    if (tab.zenStaticIcon) {
 +      tabData.image = tab.zenStaticIcon;
 +    }
 +
     // If there is a userTypedValue set, then either the user has typed something
     // in the URL bar, or a new tab was opened with a URI to load.
     // If so, we also track whether we were still in the process of loading something.
@@ -1,8 +1,8 @@
 diff --git a/browser/components/tabbrowser/content/drag-and-drop.js b/browser/components/tabbrowser/content/drag-and-drop.js
-index 70b37f93c4e8ff4ad9a2452681e468d23914c1b5..dbf2d9c83dafbe0e0b4e6caf3835edc8edf9bcf4 100644
+index f9623f82499e516050d523068e70ebaa4fe9a66a..95bcc078a86b4ec4b35f5916b7e4a5e305afba9e 100644
 --- a/browser/components/tabbrowser/content/drag-and-drop.js
 +++ b/browser/components/tabbrowser/content/drag-and-drop.js
-@@ -35,6 +35,9 @@
+@@ -42,6 +42,9 @@
    * @returns {MozTabbrowserTab|vbox}
    */
   const elementToMove = element => {
@@ -12,7 +12,7 @@ index 70b37f93c4e8ff4ad9a2452681e468d23914c1b5..dbf2d9c83dafbe0e0b4e6caf3835edc8
     if (isTab(element) || isSplitViewWrapper(element)) {
       return element;
     }
-@@ -128,6 +131,9 @@
+@@ -140,6 +143,9 @@
       }
       let draggedTab = event.dataTransfer.mozGetDataAt(TAB_DROP_TYPE, 0);
@@ -22,15 +22,15 @@ index 70b37f93c4e8ff4ad9a2452681e468d23914c1b5..dbf2d9c83dafbe0e0b4e6caf3835edc8
       if (
         (dropEffect == "move" || dropEffect == "copy") &&
         document == draggedTab.ownerDocument &&
-@@ -148,6 +154,7 @@
+@@ -161,6 +167,7 @@
           !draggedTab.group.collapsed
         ) {
           draggedTab.group.collapsedByDrag = true;
           draggedTab.group.collapsed = true;
 +          gZenFolders.animateGroupMove(draggedTab.group);
         }
         if (dropEffect == "move") {
-@@ -155,10 +162,6 @@
+@@ -168,10 +175,6 @@
           // Pinned tabs in expanded vertical mode are on a grid format and require
           // different logic to drag and drop.
@@ -41,7 +41,7 @@ index 70b37f93c4e8ff4ad9a2452681e468d23914c1b5..dbf2d9c83dafbe0e0b4e6caf3835edc8
           this._animateTabMove(event);
           return;
         }
-@@ -297,6 +300,10 @@
+@@ -310,6 +313,10 @@
       this._tabDropIndicator.hidden = true;
       event.stopPropagation();
@@ -52,7 +52,7 @@ index 70b37f93c4e8ff4ad9a2452681e468d23914c1b5..dbf2d9c83dafbe0e0b4e6caf3835edc8
       if (draggedTab && dropEffect == "copy") {
         let duplicatedDraggedTab;
         let duplicatedTabs = [];
-@@ -324,12 +331,16 @@
+@@ -337,12 +344,16 @@
         let translateOffsetY = oldTranslateY % tabHeight;
         let newTranslateX = oldTranslateX - translateOffsetX;
         let newTranslateY = oldTranslateY - translateOffsetY;
@@ -73,7 +73,7 @@ index 70b37f93c4e8ff4ad9a2452681e468d23914c1b5..dbf2d9c83dafbe0e0b4e6caf3835edc8
         if (this._tabbrowserTabs.isContainerVerticalPinnedGrid(draggedTab)) {
           // Update both translate axis for pinned vertical expanded tabs
-@@ -404,11 +415,13 @@
+@@ -417,11 +428,13 @@
           this._dragToPinPromoCard,
         ];
         let shouldPin =
@@ -87,7 +87,7 @@ index 70b37f93c4e8ff4ad9a2452681e468d23914c1b5..dbf2d9c83dafbe0e0b4e6caf3835edc8
           isTab(draggedTab) &&
           draggedTab.pinned &&
           this._tabbrowserTabs.arrowScrollbox.contains(event.target);
-@@ -484,6 +497,7 @@
+@@ -492,6 +505,7 @@
           }
         }
@@ -95,7 +95,7 @@ index 70b37f93c4e8ff4ad9a2452681e468d23914c1b5..dbf2d9c83dafbe0e0b4e6caf3835edc8
         if (shouldTranslate) {
           this.#dropAnimationEndTime = Date.now() + DROP_ANIMATION_GRACE_MS;
           let translationPromises = [];
-@@ -496,7 +510,7 @@
+@@ -504,7 +518,7 @@
                 item.removeAttribute("tabdrop-samewindow");
                 resolve();
               };
@@ -104,7 +104,7 @@ index 70b37f93c4e8ff4ad9a2452681e468d23914c1b5..dbf2d9c83dafbe0e0b4e6caf3835edc8
                 postTransitionCleanup();
               } else {
                 let onTransitionEnd = transitionendEvent => {
-@@ -580,7 +594,7 @@
+@@ -595,7 +609,7 @@
           if (tab.selected) {
             selectedTab = tab;
             indexForSelectedTab = newIndex;
@@ -113,7 +113,7 @@ index 70b37f93c4e8ff4ad9a2452681e468d23914c1b5..dbf2d9c83dafbe0e0b4e6caf3835edc8
             const droppedIntoPinnedArea = dropIndex < gBrowser.pinnedTabCount;
             const newSplitView = gBrowser.adoptSplitView(tab, {
               elementIndex: droppedIntoPinnedArea
-@@ -605,7 +619,7 @@
+@@ -620,7 +634,7 @@
             }
           }
         }
@@ -122,7 +122,7 @@ index 70b37f93c4e8ff4ad9a2452681e468d23914c1b5..dbf2d9c83dafbe0e0b4e6caf3835edc8
           const newTab = gBrowser.adoptTab(selectedTab, {
             elementIndex: indexForSelectedTab,
             selectTab: selectedTab == draggedTab,
-@@ -639,10 +653,6 @@
+@@ -654,10 +668,6 @@
               this._tabbrowserTabs.dragAndDropElements[
                 gBrowser.pinnedTabCount + unpinnedSplitViews.length - 1
               ];
@@ -133,7 +133,7 @@ index 70b37f93c4e8ff4ad9a2452681e468d23914c1b5..dbf2d9c83dafbe0e0b4e6caf3835edc8
           }
         }
       } else {
-@@ -703,6 +713,7 @@
+@@ -717,6 +727,7 @@
           let nextItem = this._tabbrowserTabs.dragAndDropElements[newIndex];
           let tabGroup = isTab(nextItem) && nextItem.group;
@@ -141,7 +141,7 @@ index 70b37f93c4e8ff4ad9a2452681e468d23914c1b5..dbf2d9c83dafbe0e0b4e6caf3835edc8
           gBrowser.loadTabs(urls, {
             inBackground,
             replace,
-@@ -744,6 +755,22 @@
+@@ -758,6 +769,22 @@
         this._expandGroupOnDrop(draggedTab);
       }
       this._resetTabsAfterDrop(draggedTab);
@@ -164,7 +164,7 @@ index 70b37f93c4e8ff4ad9a2452681e468d23914c1b5..dbf2d9c83dafbe0e0b4e6caf3835edc8
       if (
         dt.mozUserCancelled ||
-@@ -1074,11 +1101,10 @@
+@@ -1088,11 +1115,10 @@
         return this.#getHorizontalScrollboxDragTarget(event, ignoreSides);
       }
       while (target) {
@@ -180,7 +180,7 @@ index 70b37f93c4e8ff4ad9a2452681e468d23914c1b5..dbf2d9c83dafbe0e0b4e6caf3835edc8
           break;
         }
         target = target.parentNode;
-@@ -1108,6 +1134,9 @@
+@@ -1122,6 +1148,9 @@
           return null;
         }
       }
@@ -190,36 +190,43 @@ index 70b37f93c4e8ff4ad9a2452681e468d23914c1b5..dbf2d9c83dafbe0e0b4e6caf3835edc8
       return target;
     }
-@@ -1170,14 +1199,20 @@
+@@ -1188,17 +1217,24 @@
-       let releaseReservedSpace = () =>
+       let periphery = draggedTab.ownerDocument.getElementById(
-         this.#releaseSpaceInScrolledContent(periphery);
+         "tabbrowser-arrowscrollbox-periphery"
-       if (group.collapsed) {
+       );
-        // The group's tabs animate back to their full size, so hold on to the
+-      // The group's tabs animate back to their full size, so hold on to the
-        // space reserved for them until they get there.
+-      // space reserved for them until they get there.
-        group.addEventListener(
+-      group.addEventListener(
-          "TabGroupAnimationComplete",
+-        "TabGroupAnimationComplete",
-          releaseReservedSpace,
+-        () => {
-          { once: true }
+-          group.collapsedByDrag = false;
-        );
+-          this.#releaseSpaceInScrolledContent(periphery);
-        group.collapsed = false;
+-        },
-+        const expand = !group.hasAttribute("has-active");
+-        { once: true }
-+        if (expand) {
+-      );
-+          // The group's tabs animate back to their full size, so hold on to the
+-      group.collapsed = false;
-+          // space reserved for them until they get there.
+      const expand = !group.hasAttribute("has-active");
-+          group.addEventListener(
+      if (expand) {
-+            "TabGroupAnimationComplete",
+        // The group's tabs animate back to their full size, so hold on to the
-+            releaseReservedSpace,
+        // space reserved for them until they get there.
-+            { once: true }
+        group.addEventListener(
-+          );
+          "TabGroupAnimationComplete",
-+        } else {
+          () => {
-+          releaseReservedSpace();
+            group.collapsedByDrag = false;
-+        }
+            this.#releaseSpaceInScrolledContent(periphery);
-+        group.collapsed = !expand;
+          },
-+        gZenFolders.animateGroupMove(group, true);
+          { once: true }
-       } else {
+        );
-         releaseReservedSpace();
+      } else {
-       }
+        group.collapsedByDrag = false;
-@@ -1362,7 +1397,6 @@
+        this.#releaseSpaceInScrolledContent(periphery);
 +      }
 +      group.collapsed = !expand;
 +      gZenFolders.animateGroupMove(group, true);
     }
     /**
@@ -1380,7 +1416,6 @@
         // using updateDragImage. On Linux, we can use a panel.
         if (platform == "win" || platform == "macosx") {
           captureListener = function () {
@@ -227,7 +234,7 @@ index 70b37f93c4e8ff4ad9a2452681e468d23914c1b5..dbf2d9c83dafbe0e0b4e6caf3835edc8
           };
         } else {
           // Create a panel to use it in setDragImage
-@@ -1400,7 +1434,6 @@
+@@ -1418,7 +1453,6 @@
         );
         dragImageOffset = dragImageOffset * scale;
       }
@@ -235,7 +242,7 @@ index 70b37f93c4e8ff4ad9a2452681e468d23914c1b5..dbf2d9c83dafbe0e0b4e6caf3835edc8
       // _dragData.offsetX/Y give the coordinates that the mouse should be
       // positioned relative to the corner of the new window created upon
-@@ -1419,7 +1452,7 @@
+@@ -1437,7 +1471,7 @@
       let dropEffect = this.getDropEffectForTabDrag(event);
       let isMovingInTabStrip = !fromTabList && dropEffect == "move";
       let collapseTabGroupDuringDrag =
@@ -244,7 +251,7 @@ index 70b37f93c4e8ff4ad9a2452681e468d23914c1b5..dbf2d9c83dafbe0e0b4e6caf3835edc8
       tab._dragData = {
         offsetX: this._tabbrowserTabs.verticalMode
-@@ -1429,7 +1462,7 @@
+@@ -1447,7 +1481,7 @@
           ? event.screenY - window.screenY - tabOffset
           : event.screenY - window.screenY,
         scrollPos:
@@ -253,7 +260,7 @@ index 70b37f93c4e8ff4ad9a2452681e468d23914c1b5..dbf2d9c83dafbe0e0b4e6caf3835edc8
             ? this._tabbrowserTabs.pinnedTabsContainer.scrollPosition
             : this._tabbrowserTabs.arrowScrollbox.scrollPosition,
         screenX: event.screenX,
-@@ -1522,6 +1555,7 @@
+@@ -1540,6 +1574,7 @@
       if (tabStripItemElement.hasAttribute("dragtarget")) {
         return;
       }
@@ -261,7 +268,7 @@ index 70b37f93c4e8ff4ad9a2452681e468d23914c1b5..dbf2d9c83dafbe0e0b4e6caf3835edc8
       let isPinned = tab.pinned;
       let dragAndDropElements = this._tabbrowserTabs.dragAndDropElements;
       let isGrid = this._tabbrowserTabs.isContainerVerticalPinnedGrid(tab);
-@@ -1895,23 +1929,6 @@
+@@ -1913,23 +1948,6 @@
       // Slide the relevant tabs to their new position.
       // non-moving tabs adjust for RTL
@@ -285,7 +292,7 @@ index 70b37f93c4e8ff4ad9a2452681e468d23914c1b5..dbf2d9c83dafbe0e0b4e6caf3835edc8
       // moving tabs don't adjust for RTL
       for (let item of selectedElements) {
         if (
-@@ -1960,7 +1977,6 @@
+@@ -1978,7 +1996,6 @@
       for (let item of this._tabbrowserTabs.dragAndDropElements) {
         delete item._moveTogetherSelectedTabsData;
         item = elementToMove(item);
@@ -293,7 +300,7 @@ index 70b37f93c4e8ff4ad9a2452681e468d23914c1b5..dbf2d9c83dafbe0e0b4e6caf3835edc8
         item.removeAttribute("multiselected-move-together");
       }
     }
-@@ -2812,7 +2828,6 @@
+@@ -2830,7 +2847,6 @@
         tab.style.top = "";
         tab.style.maxWidth = "";
         tab.style.pointerEvents = "";
@@ -301,7 +308,7 @@ index 70b37f93c4e8ff4ad9a2452681e468d23914c1b5..dbf2d9c83dafbe0e0b4e6caf3835edc8
         tab.removeAttribute("small-stack");
         tab.removeAttribute("big-stack");
       }
-@@ -2821,11 +2836,9 @@
+@@ -2839,11 +2855,9 @@
       )) {
         label.style.width = "";
         label.style.maxWidth = "";
@@ -1,15 +1,15 @@
 diff --git a/browser/components/urlbar/UrlbarProviderHeuristicFallback.sys.mjs b/browser/components/urlbar/UrlbarProviderHeuristicFallback.sys.mjs
-index cfc232f038cd491db32e0c0ca35622360dd9dec5..4806a725ddefa9d0709020d537eae5464249a294 100644
+index e32b02941a6019703212cede4660a24b88845120..5cb363ed20d49c1ae8abedecc3b08540406b7a1b 100644
 --- a/browser/components/urlbar/UrlbarProviderHeuristicFallback.sys.mjs
 +++ b/browser/components/urlbar/UrlbarProviderHeuristicFallback.sys.mjs
-@@ -77,22 +77,26 @@ export class UrlbarProviderHeuristicFallback extends UrlbarProvider {
+@@ -76,22 +76,26 @@ export class UrlbarProviderHeuristicFallback extends UrlbarProvider {
         // Since we can't tell if this is a real URL and whether the user wants
         // to visit or search for it, we provide an alternative searchengine
         // match if the string looks like an alphanumeric origin or an e-mail.
 -        let str = queryContext.searchString;
 -        if (!URL.canParse(str)) {
 -          if (
-            lazy.UrlbarPrefs.get("keyword.enabled") &&
+-            queryContext.keywordEnabled &&
 -            (lazy.UrlUtils.looksLikeOrigin(str, {
 -              noIp: true,
 -              noPort: true,
@@ -24,7 +24,7 @@ index cfc232f038cd491db32e0c0ca35622360dd9dec5..4806a725ddefa9d0709020d537eae546
 +           }
 +        );
 +        if (
-+          lazy.UrlbarPrefs.get("keyword.enabled") &&
+          queryContext.keywordEnabled &&
 +          (lazy.UrlUtils.looksLikeUrl(searchCandidate) ||
 +            lazy.UrlUtils.looksLikeOrigin(searchCandidate, {
 +              allowPartialNumericalTLDs: true,
@@ -1,16 +0,0 @@
 diff --git a/browser/components/urlbar/UrlbarUtils.sys.mjs b/browser/components/urlbar/UrlbarUtils.sys.mjs
 index 178cd5e84fda74a28b2de59b671b3399cc28fac4..b03c6e06de4ee9a95dcb4d33d7ac9f0b053be4e1 100644
 --- a/browser/components/urlbar/UrlbarUtils.sys.mjs
 +++ b/browser/components/urlbar/UrlbarUtils.sys.mjs
@@ -214,6 +214,11 @@ export var UrlbarUtils = {
           return UrlbarShared.RESULT_GROUP.HEURISTIC_FALLBACK;
         case "UrlbarProviderHistoryUrlHeuristic":
           return UrlbarShared.RESULT_GROUP.HEURISTIC_HISTORY_URL;
 +        case "ZenUrlbarProviderGlobalActions":
 +          if (result.source == UrlbarShared.RESULT_SOURCE.WORKSPACES) {
 +            return UrlbarShared.RESULT_GROUP.ZEN_WORKSPACE;
 +          }
 +          return UrlbarShared.RESULT_GROUP.ZEN_ACTION;
         case "UrlbarProviderOmnibox":
           return UrlbarShared.RESULT_GROUP.HEURISTIC_OMNIBOX;
         case "UrlbarProviderRestrictKeywordsAutofill":
@@ -1,16 +1,16 @@
 diff --git a/browser/components/urlbar/content/UrlbarChildController.mjs b/browser/components/urlbar/content/UrlbarChildController.mjs
-index a17a4de079b69d2818388b33a2c1746cc6148c73..4fee63a22919972af08716db2d2de1c7549ff100 100644
+index 52ed36deac35d3de9f7f537313159fb4debe98a6..3bbc612a2e10eedafdabdaa8e17cf36831a6a27c 100644
 --- a/browser/components/urlbar/content/UrlbarChildController.mjs
 +++ b/browser/components/urlbar/content/UrlbarChildController.mjs
-@@ -438,7 +438,6 @@ export class UrlbarChildController {
+@@ -446,7 +446,6 @@ export class UrlbarChildController {
-     const isMac = AppConstants.platform == "macosx";
+     const isMac = UrlbarContentUtils.getPlatform() == "macosx";
     // Handle readline/emacs-style navigation bindings on Mac.
     if (
 -      isMac &&
       this.view.isOpen &&
       event.ctrlKey &&
       (event.key == "n" || event.key == "p")
-@@ -630,6 +629,8 @@ export class UrlbarChildController {
+@@ -644,6 +643,8 @@ export class UrlbarChildController {
             });
           }
           event.preventDefault();
@@ -19,7 +19,7 @@ index a17a4de079b69d2818388b33a2c1746cc6148c73..4fee63a22919972af08716db2d2de1c7
         }
         break;
       }
-@@ -934,6 +935,10 @@ export class UrlbarChildController {
+@@ -905,6 +906,10 @@ export class UrlbarChildController {
       }
       reuseEmpty = true;
     }
@@ -30,7 +30,7 @@ index a17a4de079b69d2818388b33a2c1746cc6148c73..4fee63a22919972af08716db2d2de1c7
     // The browser window exists only in chrome; a content-process input has no
     // tab to reuse, so `gBrowser` is absent and the reuse is skipped.
     if (
-@@ -943,6 +948,10 @@ export class UrlbarChildController {
+@@ -914,6 +919,10 @@ export class UrlbarChildController {
     ) {
       where = "current";
     }
@@ -1,22 +1,21 @@
-diff --git a/browser/components/urlbar/content/UrlbarInput.mjs b/browser/components/urlbar/content/UrlbarInput.mjs
+diff --git a/browser/components/urlbar/content/UrlbarInputBase.mjs b/browser/components/urlbar/content/UrlbarInputBase.mjs
-index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1a95e28b8 100644
+index 8be35b58c5369e123ca69426e852e3849bf75513..778d8aecce4da6748ecbf8b86a38c2da6e01bec5 100644
--- a/browser/components/urlbar/content/UrlbarInput.mjs
+--- a/browser/components/urlbar/content/UrlbarInputBase.mjs
-+++ b/browser/components/urlbar/content/UrlbarInput.mjs
+++ b/browser/components/urlbar/content/UrlbarInputBase.mjs
-@@ -88,6 +88,13 @@ const lazy = XPCOMUtils.declareLazy({
+@@ -83,6 +83,12 @@ if (lazy) {
-   logger: () => UrlbarShared.getLogger({ prefix: "Input" }),
+       Ci.nsIURLQueryStringStripper,
- });
+     ],
   });
 +  XPCOMUtils.defineLazyPreferenceGetter(
 +    lazy,
 +    "ZEN_URLBAR_BEHAVIOR",
 +    "zen.urlbar.behavior",
 +    'default'
 +  );
 }
-+XPCOMUtils.defineLazyPreferenceGetter(
+ const logger = () => UrlbarShared.getLogger({ prefix: "Input" });
-+  lazy,
+@@ -917,7 +923,16 @@ ${
 +  "ZEN_URLBAR_BEHAVIOR",
 +  "zen.urlbar.behavior",
 +  'default'
 +);
 +
 const UNLIMITED_MAX_RESULTS = 99;
 let getBoundsWithoutFlushing = element =>
@@ -771,7 +778,16 @@ ${
     // See _on_select().  HTMLInputElement.select() dispatches a "select"
     // event but does not set the primary selection.
     this._suppressPrimaryAdjustment = true;
@@ -33,7 +32,7 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
     this._suppressPrimaryAdjustment = false;
   }
-@@ -846,6 +862,10 @@ ${
+@@ -992,6 +1007,10 @@ ${
     hideSearchTerms = false,
     isSameDocument = false,
   } = {}) {
@@ -44,7 +43,7 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
     if (!this.#isAddressbar) {
       throw new Error(
         "Cannot set URI for UrlbarInput that is not an address bar"
-@@ -1143,7 +1163,16 @@ ${
+@@ -1289,7 +1308,16 @@ ${
       this.searchModeSwitcher?.updateSearchIcon();
     }
@@ -61,7 +60,17 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
   }
   /**
-@@ -1726,7 +1755,11 @@ ${
+@@ -1401,6 +1429,9 @@ ${
       where,
       query: searchString,
     });
 +    if (where != "current" && this.sapName != "searchbar") {
 +      this.handleRevert();
 +    }
     this.controller.openSERP(
       engine.id,
       searchString,
@@ -1884,7 +1915,11 @@ ${
     openParams.avoidBrowserFocus = keepViewOpen;
     if (!this.#providesSearchMode(result) && !keepViewOpen) {
@@ -74,12 +83,12 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
     }
     if (isCanonized) {
-@@ -3016,6 +3049,42 @@ ${
+@@ -3181,6 +3216,42 @@ ${
     await this.#updateLayoutBreakoutDimensions();
   }
 +  zenFormatURLValue() {
-+    return this.#lazy.valueFormatter._formatURL();
+    return this.#getValueFormatter().update();
 +  }
 +
 +  get zenUrlbarBehavior() {
@@ -117,8 +126,11 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
   startLayoutExtend() {
     if (!this.#allowBreakout || this.hasAttribute("breakout-extend")) {
       // Do not expand if the Urlbar does not support being expanded or it is
-@@ -3030,6 +3099,13 @@ ${
+@@ -3193,8 +3264,16 @@ ${
     }
     this.toggleAttribute("breakout-extend", true);
 +    this.#showBreakoutPopover();
     this.#updateTextboxPosition();
 +    this.window.gZenUIManager.onUrlbarOpen();
@@ -131,7 +143,7 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
     // Enable the animation only after the first extend call to ensure it
     // doesn't run when opening a new window.
     if (!this.hasAttribute("breakout-extend-animate")) {
-@@ -3053,6 +3129,29 @@ ${
+@@ -3218,7 +3297,33 @@ ${
       return;
     }
@@ -159,9 +171,13 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
 +    this.removeAttribute("zen-floating-urlbar");
 +
     this.toggleAttribute("breakout-extend", false);
 +    if (this.#isAddressbar) {
 +      this.#hideBreakoutPopover();
 +    }
     this.#updateTextboxPosition();
   }
-@@ -3091,7 +3190,7 @@ ${
+ 
@@ -3256,7 +3361,7 @@ ${
     forceUnifiedSearchButtonAvailable = false
   ) {
     let prevState = this.getAttribute("pageproxystate");
@@ -170,20 +186,51 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
     this.setAttribute("pageproxystate", state);
     this._inputContainer.setAttribute("pageproxystate", state);
     this._identityBox?.setAttribute("pageproxystate", state);
-@@ -3355,10 +3454,12 @@ ${
+@@ -3533,7 +3638,11 @@ ${
       return;
     }
-     this.style.top = px(
+-    this.style.top = px(getUntransformedTop(this.parentNode));
 +    this.style.top = px(
 +      this.window.gZenVerticalTabsManager._hasSetSingleToolbar ?
-       this.parentNode.getBoxQuads({
+      getUntransformedTop(this.parentNode)
-         ignoreTransforms: true,
+      : (UrlbarContentUtils.getPlatform() == "macosx" ? -2 : -5)
-         flush: false,
+    );
       })[0].p1.y
 +      : (AppConstants.platform == "macosx" ? -2 : -5)
     );
   }
-@@ -3417,9 +3518,10 @@ ${
+   #updateTextboxPositionNextFrame() {
@@ -3553,12 +3662,29 @@ ${
     this.removeAttribute("breakout");
     this.parentNode.removeAttribute("breakout");
     this.style.top = "";
 +    this.#hideBreakoutPopover();
 +    this._layoutBreakoutUpdateKey = {};
 +  }
 +
 +  #showBreakoutPopover() {
 +    if (this.#isAddressbar) {
 +      this.setAttribute("popover", "manual");
 +    }
 +    if (!this.matches(":popover-open")) {
 +      this.showPopover();
 +    }
 +    this.#fixAddressbarSearchbarOrder();
 +  }
 +
 +  #hideBreakoutPopover() {
     try {
       this.hidePopover();
     } catch (ex) {
       // No big deal if not a popover already.
     }
 -    this._layoutBreakoutUpdateKey = {};
 +    if (this.#isAddressbar) {
 +      this.removeAttribute("popover");
 +    }
   }
   incrementBreakoutBlockerCount() {
@@ -3591,9 +3717,10 @@ ${
           return;
         }
@@ -195,7 +242,19 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
         );
         if (this.#breakoutBlockerCount) {
-@@ -3929,6 +4031,7 @@ ${
+@@ -3602,8 +3729,9 @@ ${
         this.setAttribute("breakout", "true");
         this.parentNode.setAttribute("breakout", "true");
 -        this.showPopover();
 -        this.#fixAddressbarSearchbarOrder();
 +        if (!this.#isAddressbar || this.hasAttribute("breakout-extend")) {
 +          this.#showBreakoutPopover();
 +        }
         this.#updateTextboxPosition();
         resolve();
@@ -4108,6 +4236,7 @@ ${
   }
   _toggleActionOverride(event) {
@@ -203,7 +262,7 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
     if (
       event.keyCode == KeyEvent.DOM_VK_SHIFT ||
       event.keyCode == KeyEvent.DOM_VK_ALT ||
-@@ -4027,9 +4130,10 @@ ${
+@@ -4206,9 +4335,10 @@ ${
     if (!this.#isAddressbar) {
       return val;
     }
@@ -216,36 +275,36 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
 +        : val;
     // Only trim value if the directionality doesn't change to RTL and we're not
     // showing a strikeout https protocol.
-     return this.controller.isTextDirectionRTL(trimmedValue) ||
+     return UrlbarContentUtils.isTextDirectionRTL(trimmedValue, window) ||
-@@ -4235,6 +4339,11 @@ ${
+@@ -4410,6 +4540,11 @@ ${
     keepViewOpen = false,
     browserId = null,
   }) {
 +    where = this.window.gZenUIManager.getOpenUILinkWhere(
-+      url,
+      loadRequest.urlLoad?.url ?? "",
 +      this.window.gBrowser.selectedBrowser,
 +      where
 +    );
-     let userTypedValue;
+     let keyDownEnterDeferred;
-     if (this.#isAddressbar && where == "current") {
+     if (
-       // Make sure URL is formatted properly (don't show punycode).
+       this._keyDownEnterDeferred &&
-@@ -4576,6 +4685,7 @@ ${
+@@ -4731,6 +4866,7 @@ ${
-       this.setResultForCurrentValue(null);
+           this.setResultForCurrentValue(null);
-       this.handleCommand();
+           this.handleCommand();
-       this.controller.clearLastQueryContextCache();
+           this.controller.clearLastQueryContextCache();
-+      this.view.close();
+          this.view.close();
-       this._suppressStartQuery = false;
+           this._suppressStartQuery = false;
-     });
+         });
-@@ -4583,7 +4693,6 @@ ${
+@@ -4742,7 +4878,6 @@ ${
-     contextMenu.addEventListener("popupshowing", () => {
+         // Close the results pane, because paste and go doesn't want a result
-       // Close the results pane when the input field contextual menu is open,
+         // selection. This has to happen before the menu opens: ending
-       // because paste and go doesn't want a result selection.
+         // breakout-extend once it's open keeps it from showing (bug 2037468).
-      this.view.close();
+-        this.view.close();
-       let controller =
+         let controller =
-         this.document.commandDispatcher.getControllerForCommand("cmd_paste");
+           this.document.commandDispatcher.getControllerForCommand("cmd_paste");
-@@ -4850,7 +4959,11 @@ ${
+@@ -5025,7 +5160,11 @@ ${
     if (!engineName && !source && !this.hasAttribute("searchmode")) {
       return;
     }
@@ -258,7 +317,7 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
     if (this._searchModeIndicatorTitle) {
       this._searchModeIndicatorTitle.textContent = "";
       this._searchModeIndicatorTitle.removeAttribute("data-l10n-id");
-@@ -5149,6 +5262,7 @@ ${
+@@ -5335,6 +5474,7 @@ ${
     this.document.l10n.setAttributes(
       this.inputField,
@@ -266,10 +325,10 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
       l10nId,
       l10nId == "urlbar-placeholder-with-name"
         ? { name: engineName }
-@@ -5199,6 +5313,12 @@ ${
+@@ -5385,6 +5525,12 @@ ${
     }
-     lazy.logger.debug("Blur Event");
+     logger().debug("Blur Event");
 +    if (
 +      this.document.commandDispatcher.focusedElement == this.inputField &&
 +      !UrlbarPrefs.get("closeOnWindowBlur")
@@ -279,7 +338,7 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
     // We cannot count every blur events after a missed engagement as abandoment
     // because the user may have clicked on some view element that executes
     // a command causing a focus change. For example opening preferences from
-@@ -5276,6 +5396,11 @@ ${
+@@ -5464,6 +5610,11 @@ ${
   }
   _on_click(event) {
@@ -291,7 +350,7 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
     switch (event.target) {
       case this.inputField:
       case this._inputContainer:
-@@ -5371,10 +5496,11 @@ ${
+@@ -5558,10 +5709,11 @@ ${
       }
       if (untrim) {
         this.setValue(this._untrimmedValue);
@@ -304,7 +363,7 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
       this.view.autoOpen({ event });
     } else {
       if (this._untrimOnFocusAfterKeydown) {
-@@ -5414,9 +5540,16 @@ ${
+@@ -5605,9 +5757,16 @@ ${
   }
   _on_mousedown(event) {
@@ -322,7 +381,7 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
         if (
           event.composedTarget != this.inputField &&
           event.composedTarget != this._inputContainer
-@@ -5426,6 +5559,10 @@ ${
+@@ -5617,6 +5776,10 @@ ${
         this.focusedViaMousedown = !this.focused;
         this.#preventClickSelectsAll = this.focused;
@@ -333,16 +392,16 @@ index 319fb6870ec18d87b9f1263bd960edaa39b0447c..554cc90fb2307450ddc68033968cefd1
         // Keep the focus status, since the attribute may be changed
         // upon calling this.focus().
-@@ -5463,7 +5600,7 @@ ${
+@@ -5654,7 +5817,7 @@ ${
         // view open on tab switch, and the TabSelect event arrived earlier.
         // Also ignore mousedown on the urlbarView context menu: opening/closing the
         // view is already handled by the result opening flow.
 -        if (event.target.closest?.("tab, #urlbarView-context-menu")) {
-+        if (event.target.closest?.("tab, #urlbarView-context-menu") || event.target.closest?.("#tabs-newtab-button")) {
+        if (event.target.closest?.("tab, #urlbarView-context-menu") || event.target.closest?.("menupopup") || event.target.closest?.("#tabs-newtab-button")) {
           break;
         }
-@@ -5754,7 +5891,7 @@ ${
+@@ -5948,7 +6111,7 @@ ${
     // When we are in actions search mode we can show more results so
     // increase the limit.
     let maxResults =
@@ -1,8 +1,8 @@
 diff --git a/browser/components/urlbar/content/UrlbarShared.mjs b/browser/components/urlbar/content/UrlbarShared.mjs
-index 4e67dad66ae006842abc6eed547e4a244320d57a..393b61b4d2543c73e60afd334a353f36119ae73e 100644
+index 0ac5330223c84fbb98880a5c2d83ae58a8f3079e..ff488cf5a2c8b7857a8e145e40aaf861cfa655ec 100644
 --- a/browser/components/urlbar/content/UrlbarShared.mjs
 +++ b/browser/components/urlbar/content/UrlbarShared.mjs
-@@ -100,6 +100,7 @@ export const UrlbarShared = {
+@@ -158,6 +158,7 @@ export const UrlbarShared = {
     // `looksLikeOrigin()` returned `LOOKS_LIKE_ORIGIN.OTHER` for this token.
     // It may or may not be an origin.
     POSSIBLE_ORIGIN_BUT_SEARCH_ALLOWED: 12,
@@ -10,7 +10,7 @@ index 4e67dad66ae006842abc6eed547e4a244320d57a..393b61b4d2543c73e60afd334a353f36
   }),
   /**
-@@ -120,6 +121,7 @@ export const UrlbarShared = {
+@@ -178,6 +179,7 @@ export const UrlbarShared = {
     TITLE: "#",
     URL: "$",
     ACTION: ">",
@@ -18,7 +18,7 @@ index 4e67dad66ae006842abc6eed547e4a244320d57a..393b61b4d2543c73e60afd334a353f36
   }),
   // Defines UrlbarResult types.
-@@ -165,6 +167,8 @@ export const UrlbarShared = {
+@@ -223,6 +225,8 @@ export const UrlbarShared = {
     OTHER_NETWORK: 6,
     ADDON: 7,
     ACTIONS: 8,
@@ -27,7 +27,7 @@ index 4e67dad66ae006842abc6eed547e4a244320d57a..393b61b4d2543c73e60afd334a353f36
   }),
   // Results are categorized into groups to help the muxer compose them.  See
-@@ -200,6 +204,8 @@ export const UrlbarShared = {
+@@ -258,6 +262,8 @@ export const UrlbarShared = {
     SEMANTIC_HISTORY: "semanticHistory",
     SUGGESTED_INDEX: "suggestedIndex",
     TAIL_SUGGESTION: "tailSuggestion",
@@ -36,7 +36,7 @@ index 4e67dad66ae006842abc6eed547e4a244320d57a..393b61b4d2543c73e60afd334a353f36
   }),
   // Defines provider types.
-@@ -385,6 +391,14 @@ export const UrlbarShared = {
+@@ -443,6 +449,14 @@ export const UrlbarShared = {
         telemetryLabel: "actions",
         uiLabel: "urlbar-searchmode-actions3",
       },
@@ -51,7 +51,7 @@ index 4e67dad66ae006842abc6eed547e4a244320d57a..393b61b4d2543c73e60afd334a353f36
     ]);
   },
-@@ -402,6 +416,7 @@ export const UrlbarShared = {
+@@ -460,6 +474,7 @@ export const UrlbarShared = {
     if (UrlbarPrefs.get("scotchBonnet.enableOverride")) {
       keys.push(this.RESTRICT_TOKENS.ACTION);
     }
@@ -59,3 +59,23 @@ index 4e67dad66ae006842abc6eed547e4a244320d57a..393b61b4d2543c73e60afd334a353f36
     return new Set(keys);
   },
@@ -1032,6 +1047,11 @@ export const UrlbarShared = {
           return UrlbarShared.RESULT_GROUP.HEURISTIC_FALLBACK;
         case "UrlbarProviderHistoryUrlHeuristic":
           return UrlbarShared.RESULT_GROUP.HEURISTIC_HISTORY_URL;
 +        case "ZenUrlbarProviderGlobalActions":
 +          if (result.source == UrlbarShared.RESULT_SOURCE.WORKSPACES) {
 +            return UrlbarShared.RESULT_GROUP.ZEN_WORKSPACE;
 +          }
 +          return UrlbarShared.RESULT_GROUP.ZEN_ACTION;
         case "UrlbarProviderOmnibox":
           return UrlbarShared.RESULT_GROUP.HEURISTIC_OMNIBOX;
         case "UrlbarProviderRestrictKeywordsAutofill":
@@ -1060,6 +1080,7 @@ export const UrlbarShared = {
       case "UrlbarProviderAboutPages":
         return UrlbarShared.RESULT_GROUP.ABOUT_PAGES;
       case "UrlbarProviderInputHistory":
 +      case "ZenUrlbarProviderSidebar":
         return UrlbarShared.RESULT_GROUP.INPUT_HISTORY;
       case "UrlbarProviderQuickSuggest":
         return UrlbarShared.RESULT_GROUP.GENERAL_PARENT;
@@ -0,0 +1,13 @@
 diff --git a/browser/extensions/newtab/lib/AboutPreferences.sys.mjs b/browser/extensions/newtab/lib/AboutPreferences.sys.mjs
 index 4562efc05b76d5dddd35bda79bd7d5d98a51ffc9..ad9b6f55f5e77065ce74535daf6457a5c4b44058 100644
 --- a/browser/extensions/newtab/lib/AboutPreferences.sys.mjs
 +++ b/browser/extensions/newtab/lib/AboutPreferences.sys.mjs
@@ -355,7 +355,7 @@ export class AboutPreferences {
       // Firefox 155+ registers `homepage` and `customHomepage` in
       // components/preferences. They can't be registered twice, so skip them
       // on 155+. Drop this condition once 155 reaches Release.
 -      if (Services.vc.compare(AppConstants.MOZ_APP_VERSION, "155.0a1") < 0) {
 +      if (false) {
         groups.homepage = this._setupHomepageGroup(window);
         groups.customHomepage = this._setupCustomHomepageGroup(window);
       }
@@ -1,10 +1,10 @@
 diff --git a/browser/modules/ExtensionsUI.sys.mjs b/browser/modules/ExtensionsUI.sys.mjs
-index 95a4b6e40bd568c3ea5003b648b0acbf96bbb725..6ab8a658721aa6470d482dc958e4b3ac78f49f44 100644
+index 73ef024602cb4554a024de4ddef83f492adc33ef..959c3403a48a3e4294ad5d2f72bad0e5d4fbfd75 100644
 --- a/browser/modules/ExtensionsUI.sys.mjs
 +++ b/browser/modules/ExtensionsUI.sys.mjs
-@@ -502,7 +502,7 @@ export var ExtensionsUI = {
+@@ -507,7 +507,7 @@ export var ExtensionsUI = {
-         eventCallback,
+         // right after the panel opens can't accidentally grant permissions).
-         removeOnDismissal: true,
+         autofocus: true,
         popupOptions: {
 -          position: "bottomright topright",
 +          position: window.gZenUIManager.panelUIPosition(),
@@ -1,8 +1,8 @@
 diff --git a/browser/themes/shared/tabbrowser/content-area.css b/browser/themes/shared/tabbrowser/content-area.css
-index 2374ed38bd9361d6c7e1886117099c6761e403b8..72f1f52a13096f19ca4009037ad0cdc880775ff7 100644
+index 86400b643c8b2af4207d226fbd6d91e5e74548b9..3044e4ab87b7ebcfaa2ac624680da1cc5653c861 100644
 --- a/browser/themes/shared/tabbrowser/content-area.css
 +++ b/browser/themes/shared/tabbrowser/content-area.css
-@@ -239,7 +239,6 @@
+@@ -166,7 +166,6 @@
   min-width: 0;
   /* We want to be able to show the frame color behind the clipped radiused corner */
@@ -10,7 +10,7 @@ index 2374ed38bd9361d6c7e1886117099c6761e403b8..72f1f52a13096f19ca4009037ad0cdc8
   display: grid;
   /**
-@@ -425,7 +424,6 @@
+@@ -355,7 +354,6 @@
   }
   browser:is([blank], [pendingpaint]) {
@@ -18,21 +18,21 @@ index 2374ed38bd9361d6c7e1886117099c6761e403b8..72f1f52a13096f19ca4009037ad0cdc8
   }
   /* Exclude browsers with smartwindow-content attribute which inherit
-@@ -865,7 +863,7 @@ split-view-footer {
+@@ -735,7 +733,7 @@ split-view-footer {
 .dialogStack {
   z-index: var(--browser-stack-z-index-dialog-stack);
 -  position: absolute;
 +  position: fixed;
-   inset: 0;
+ 
   /* --browser-with-dialog set on browser[tabDialogShowing], we want to position the overlay
      only on the top of the <browser> element so it doesn't overlap the DevTools toolbox */
-@@ -1034,7 +1032,7 @@ split-view-footer {
+@@ -909,7 +907,7 @@ split-view-footer {
 .dialogOverlay[topmost="true"],
 #window-modal-dialog::backdrop {
 -  background-color: var(--background-color-overlay);
 +  background-color: light-dark(rgba(255, 255, 255, .3), rgba(0, 0, 0, .3));
-   border-radius: var(--chrome-block-radius);
+ }
-   .browserSidebarContainer.responsive-mode & {
+ .dialogOverlay[hideContent="true"][topmost="true"] {
@@ -1,5 +1,5 @@
 diff --git a/browser/themes/shared/toolbarbuttons.css b/browser/themes/shared/toolbarbuttons.css
-index 94b1a2a841d8fd47a491616d52e5bf544f0c0bf9..9e98266b98c6b66fed26fec12fa3391fc5fcc79b 100644
+index bbf906c7bf1d6f0d71744953aeeb750c5181639a..dd116e22c38dc376c9c6b34dfa569bf4661a8971 100644
 --- a/browser/themes/shared/toolbarbuttons.css
 +++ b/browser/themes/shared/toolbarbuttons.css
@@ -13,20 +13,6 @@
@@ -23,7 +23,7 @@ index 94b1a2a841d8fd47a491616d52e5bf544f0c0bf9..9e98266b98c6b66fed26fec12fa3391f
   &:where([uidensity="compact"]) {
     --toolbarbutton-padding-inner: var(--toolbarbutton-padding-inner-compact);
     --bookmark-block-padding: 1px;
-@@ -123,9 +109,7 @@
+@@ -119,9 +105,7 @@
 #TabsToolbar {
   /* Override the inner padding to ensure the dimensions match the tabs, but also making sure
      different types of buttons (combined-buttons-dropmarker or text) still look correct. */
@@ -33,18 +33,16 @@ index 94b1a2a841d8fd47a491616d52e5bf544f0c0bf9..9e98266b98c6b66fed26fec12fa3391f
 }
 /* Primary toolbar buttons */
-@@ -205,8 +189,8 @@ toolbar .toolbarbutton-1 {
+@@ -174,7 +158,7 @@
-   > .toolbarbutton-icon {
+ toolbar .toolbarbutton-1 {
-     /* horizontal padding + actual icon width */
+   /* horizontal padding + actual icon width */
-    width: calc(2 * var(--toolbarbutton-padding-inner) + 16px);
+-  --toolbarbutton-icon-size: calc(2 * var(--toolbarbutton-padding-inner) + 16px);
-    height: calc(2 * var(--toolbarbutton-padding-inner) + 16px);
+  --toolbarbutton-icon-size: calc(2 * var(--toolbarbutton-padding-inner) + var(--zen-toolbar-button-size, 16px));
 +    width: calc(2 * var(--toolbarbutton-padding-inner) + var(--zen-toolbar-button-size, 16px));
 +    height: calc(2 * var(--toolbarbutton-padding-inner) + var(--zen-toolbar-button-size, 16px));
   }
-   > .toolbarbutton-text {
+   appearance: none;
-@@ -216,7 +200,7 @@ toolbar .toolbarbutton-1 {
+   margin: 0;
@@ -214,7 +198,7 @@ toolbar .toolbarbutton-1 {
      * height as the button icons and the same vertical padding, but as a minimum,
      * because otherwise an increase in text sizes would break things.
      */
@@ -62,7 +60,7 @@ index 94b1a2a841d8fd47a491616d52e5bf544f0c0bf9..9e98266b98c6b66fed26fec12fa3391f
     display: none;
   }
-@@ -536,7 +520,7 @@ toolbarbutton.bookmark-item:not(.subviewbutton) {
+@@ -427,7 +411,7 @@ toolbarbutton.bookmark-item:not(.subviewbutton) {
      */
     align-items: stretch;
     > .toolbarbutton-icon {
@@ -1,8 +1,8 @@
-diff --git a/browser/themes/shared/urlbar-searchbar.css b/browser/themes/shared/urlbar-searchbar.css
+diff --git a/browser/themes/shared/urlbar.css b/browser/themes/shared/urlbar.css
-index 149f123e26cd79e89432dfeb504ca7218ee04810..7e0e6d981d6c2aa53bc2a76d82d2078419659065 100644
+index 06183c82e2869290a5fb476c47fb7db92bbef57f..c64cde1eef50d3457fb1c540d95fe3b8aa087294 100644
--- a/browser/themes/shared/urlbar-searchbar.css
+--- a/browser/themes/shared/urlbar.css
-+++ b/browser/themes/shared/urlbar-searchbar.css
+++ b/browser/themes/shared/urlbar.css
-@@ -19,8 +19,8 @@
+@@ -24,8 +24,8 @@
   @media not -moz-pref("browser.nova.enabled") {
     --urlbar-basic-component-size: calc(var(--urlbar-height) - 2 * (var(--urlbar-input-container-border-width) + var(--urlbar-input-container-padding)));
@@ -13,7 +13,7 @@ index 149f123e26cd79e89432dfeb504ca7218ee04810..7e0e6d981d6c2aa53bc2a76d82d20784
   }
   @media (max-width: 770px) {
     --urlbar-container-min-width: 240px;
-@@ -127,7 +127,7 @@ toolbar[inactive="true"] .urlbar,
+@@ -143,7 +143,7 @@ toolbar[inactive="true"] .urlbar,
 .urlbar:not([usertyping]) > .urlbar-input-container > .urlbar-go-button,
 .urlbar:not(#searchbar-new, [focused]) > .urlbar-input-container > .urlbar-go-button,
 #urlbar-revert-button-container {
@@ -22,7 +22,7 @@ index 149f123e26cd79e89432dfeb504ca7218ee04810..7e0e6d981d6c2aa53bc2a76d82d20784
 }
 /* Document Picture-in-Picture API window */
-@@ -405,6 +405,10 @@ toolbar[inactive="true"] .urlbar,
+@@ -434,6 +434,10 @@ toolbar[inactive="true"] .urlbar,
   .urlbar:not([focused])[textoverflow="left"][domaindir="rtl"] > .urlbar-input-container > .urlbar-input-box > & {
     mask-image: linear-gradient(to right, transparent var(--urlbar-scheme-size), black calc(var(--urlbar-scheme-size) + 3ch));
   }
@@ -33,7 +33,7 @@ index 149f123e26cd79e89432dfeb504ca7218ee04810..7e0e6d981d6c2aa53bc2a76d82d20784
 }
 #urlbar-scheme {
-@@ -476,10 +480,15 @@ toolbar[inactive="true"] .urlbar,
+@@ -505,10 +509,15 @@ toolbar[inactive="true"] .urlbar,
   }
   .urlbar[breakout][breakout-extend] {
@@ -0,0 +1,37 @@
 #filter dumbComments emptyLines substitution
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 <svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" fill="context-fill" fill-opacity="context-fill-opacity" class="zen-library-icon" viewBox="4 4 24 24"><style>@property --zen-triangle-anim { syntax: &apos;&lt;number&gt;&apos;; initial-value: 1; inherits: false; }
    @property --zen-circle-anim { syntax: &apos;&lt;number&gt;&apos;; initial-value: 1; inherits: false; }
    @keyframes StarBackward {
      0% { transform: rotate(120deg); }
      100% { transform: rotate(0deg); }
    }
    @keyframes TriangleBackward {
      0% { --zen-triangle-anim: 1; }
      100% { --zen-triangle-anim: 0; }
    }
    @keyframes CircleBackward {
      0% { --zen-circle-anim: 1; }
      100% { --zen-circle-anim: 0; }
    }
    @keyframes GlowBackward {
      0% { opacity: 0.4; }
      100% { opacity: 0; }
    }
    @keyframes GlowElementsBackward {
      0% { opacity: 0.5; }
      100% { opacity: 0; }
    }
    .zen-library-star { transform-origin: 10px 10.2px; animation: StarBackward 0.4s cubic-bezier(0.4, 0, 0.2, 1) forwards; }
    .zen-library-triangle-group { transform-origin: 17px 9.2px; animation: TriangleBackward 0.4s cubic-bezier(0.4, 0, 0.2, 1) forwards; transform: translate(calc(var(--zen-triangle-anim) * 2px), 0px) rotate(calc(var(--zen-triangle-anim) * 365deg)) scale(max(1 - var(--zen-triangle-anim) / 0.65, (var(--zen-triangle-anim) - 0.65) / 0.35)); }
    .zen-library-circle { transform-origin: 0px 0px; animation: CircleBackward 0.4s cubic-bezier(0.4, 0, 0.2, 1) forwards; transform: translate(calc(var(--zen-circle-anim) * 1px), calc(var(--zen-circle-anim) * -1.5px)) scale(max(0, max((var(--zen-circle-anim) - 0.75) / 0.25, min(1, 1 - (var(--zen-circle-anim) - 0.3) / 0.35)))); }
    .zen-library-glow { filter: blur(2px); animation: GlowBackward 0.4s cubic-bezier(0.4, 0, 0.2, 1) forwards; }
    .zen-library-glow-element { filter: blur(2px); animation: GlowElementsBackward 0.4s cubic-bezier(0.4, 0, 0.2, 1) forwards; }
    .zen-library-glow-bg, .zen-library-glow-element { fill: transparent !important; stroke: none !important; }
    .zen-library-glow-rays { stroke: transparent !important; fill: none !important; }
    @media (prefers-color-scheme: dark) {
      .zen-library-glow-bg, .zen-library-glow-element { fill: white !important; }
      .zen-library-glow-rays { stroke: white !important; }
    }</style><defs><mask id="zen-library-box-mask"><rect width="40" height="40" x="-10" y="-10" fill="#fff"/><rect width="40" height="40" x="-10" y="11.635" fill="#000"/></mask></defs><g fill-rule="evenodd"><g mask="url(#zen-library-box-mask)"><path d="M7.773 11.635c.363.228.467.44.445.659l-.182 1.788a.579.579 0 0 0 .946.503l1.38-1.153a.58.58 0 0 1 .604-.085l1.644.725a.578.578 0 0 0 .77-.745l-.679-1.692a.58.58 0 0 1 .115-.577l1.198-1.34a.578.578 0 0 0-.47-.962l-1.794.121a.58.58 0 0 1-.539-.286l-.904-1.553a.578.578 0 0 0-1.06.15l-.439 1.743a.58.58 0 0 1-.438.424l-1.757.38a.578.578 0 0 0-.186 1.055z" class="zen-library-star zen-library-glow-element"/><path d="M7.773 11.635c.363.228.467.44.445.659l-.182 1.788a.579.579 0 0 0 .946.503l1.38-1.153a.58.58 0 0 1 .604-.085l1.644.725a.578.578 0 0 0 .77-.745l-.679-1.692a.58.58 0 0 1 .115-.577l1.198-1.34a.578.578 0 0 0-.47-.962l-1.794.121a.58.58 0 0 1-.539-.286l-.904-1.553a.578.578 0 0 0-1.06.15l-.439 1.743a.58.58 0 0 1-.438.424l-1.757.38a.578.578 0 0 0-.186 1.055z" class="zen-library-star"/></g><g transform="translate(14, 6.2)"><circle r="1.4" class="zen-library-circle zen-library-glow-element"/><circle r="1" class="zen-library-circle"/></g><g class="zen-library-triangle-group"><g transform="translate(17, 9.2)"><path d="M-1.1 1.8c-.3.2-.6 0-.6-.3v-3c0-.3.3-.5.6-.3L1.4-.4c.3.2.3.6 0 .8Z" class="zen-library-triangle zen-library-glow-element"/><path d="M-1.1 1.8c-.3.2-.6 0-.6-.3v-3c0-.3.3-.5.6-.3L1.4-.4c.3.2.3.6 0 .8Z" class="zen-library-triangle"/></g></g><g class="zen-library-glow"><path d="m6.6 6.6 1.44 6.1h9.92l1.44-6.1Z" class="zen-library-glow-bg"/><path d="m6.1 6.6 1.94 6.1h9.92l1.94-6.1" class="zen-library-glow-rays"/></g><path d="M7.218 13.287c0-.456.37-.826.826-.826h9.913c.457 0 .826.37.826.826v4.131a3.304 3.304 0 0 1-3.304 3.304h-4.956a3.305 3.305 0 0 1-3.305-3.304zm3.391 1.239c0-.456.37-.826.826-.826h3.304a.826.826 0 1 1 0 1.652h-3.304a.826.826 0 0 1-.826-.826" class="zen-library-box"/></g></svg>
@@ -143,6 +143,7 @@
 *  skin/classic/browser/zen-icons/tracking-protection.svg                      (../shared/zen-icons/nucleo/tracking-protection.svg) 
 *  skin/classic/browser/zen-icons/translations.svg                      (../shared/zen-icons/nucleo/translations.svg) 
 *  skin/classic/browser/zen-icons/trash.svg                      (../shared/zen-icons/nucleo/trash.svg) 
 *  skin/classic/browser/zen-icons/u-turn-to-left.svg                      (../shared/zen-icons/nucleo/u-turn-to-left.svg) 
 *  skin/classic/browser/zen-icons/unpin.svg                      (../shared/zen-icons/nucleo/unpin.svg) 
 *  skin/classic/browser/zen-icons/video-blocked-fill.svg                      (../shared/zen-icons/nucleo/video-blocked-fill.svg) 
 *  skin/classic/browser/zen-icons/video-fill.svg                      (../shared/zen-icons/nucleo/video-fill.svg) 
@@ -294,6 +295,7 @@
 *  skin/classic/browser/zen-icons/tracking-protection.svg                      (../shared/zen-icons/nucleo/tracking-protection.svg) 
 *  skin/classic/browser/zen-icons/translations.svg                      (../shared/zen-icons/nucleo/translations.svg) 
 *  skin/classic/browser/zen-icons/trash.svg                      (../shared/zen-icons/nucleo/trash.svg) 
 *  skin/classic/browser/zen-icons/u-turn-to-left.svg                      (../shared/zen-icons/nucleo/u-turn-to-left.svg) 
 *  skin/classic/browser/zen-icons/unpin.svg                      (../shared/zen-icons/nucleo/unpin.svg) 
 *  skin/classic/browser/zen-icons/video-blocked-fill.svg                      (../shared/zen-icons/nucleo/video-blocked-fill.svg) 
 *  skin/classic/browser/zen-icons/video-fill.svg                      (../shared/zen-icons/nucleo/video-fill.svg) 
@@ -445,6 +447,7 @@
 *  skin/classic/browser/zen-icons/tracking-protection.svg                      (../shared/zen-icons/nucleo/tracking-protection.svg) 
 *  skin/classic/browser/zen-icons/translations.svg                      (../shared/zen-icons/nucleo/translations.svg) 
 *  skin/classic/browser/zen-icons/trash.svg                      (../shared/zen-icons/nucleo/trash.svg) 
 *  skin/classic/browser/zen-icons/u-turn-to-left.svg                      (../shared/zen-icons/nucleo/u-turn-to-left.svg) 
 *  skin/classic/browser/zen-icons/unpin.svg                      (../shared/zen-icons/nucleo/unpin.svg) 
 *  skin/classic/browser/zen-icons/video-blocked-fill.svg                      (../shared/zen-icons/nucleo/video-blocked-fill.svg) 
 *  skin/classic/browser/zen-icons/video-fill.svg                      (../shared/zen-icons/nucleo/video-fill.svg) 
@@ -543,4 +546,11 @@
 *  skin/classic/browser/zen-icons/selectable/warning.svg          (../shared/zen-icons/common/selectable/warning.svg) 
 *  skin/classic/browser/zen-icons/selectable/water.svg          (../shared/zen-icons/common/selectable/water.svg) 
 *  skin/classic/browser/zen-icons/selectable/weight.svg          (../shared/zen-icons/common/selectable/weight.svg) 
 *  skin/classic/browser/zen-icons/library/library-boosts-sprite.svg          (../shared/zen-icons/common/library/library-boosts-sprite.svg) 
 *  skin/classic/browser/zen-icons/library/library-downloads-sprite.svg          (../shared/zen-icons/common/library/library-downloads-sprite.svg) 
 *  skin/classic/browser/zen-icons/library/library-history-sprite.svg          (../shared/zen-icons/common/library/library-history-sprite.svg) 
 *  skin/classic/browser/zen-icons/library/library-media-sprite.svg          (../shared/zen-icons/common/library/library-media-sprite.svg) 
 *  skin/classic/browser/zen-icons/library/library-spaces-sprite.svg          (../shared/zen-icons/common/library/library-spaces-sprite.svg) 
 *  skin/classic/browser/zen-icons/library/library-sprite.svg          (../shared/zen-icons/common/library/library-sprite.svg) 
 *  skin/classic/browser/zen-icons/library/library.svg          (../shared/zen-icons/common/library/library.svg) 
  skin/classic/browser/zen-icons/icons.css                      (../shared/zen-icons/icons.css) 
@@ -0,0 +1,5 @@
 #filter dumbComments emptyLines substitution
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If applicable, you may obtain one at
 # http://mozilla.org/MPL/2.0/.
 <svg xmlns="http://www.w3.org/2000/svg" width="18" height="18" fill="context-fill" fill-opacity="context-fill-opacity" viewBox="0 0 18 18"><path d="M5.22 2.22a.75.75 0 1 1 1.06 1.06L4.06 5.5H12a4.5 4.5 0 0 1 0 9H8.25a.75.75 0 0 1 0-1.5H12a3 3 0 0 0 0-6H4.06l2.22 2.22a.75.75 0 0 1-1.06 1.06l-3.5-3.5a.75.75 0 0 1-.165-.812l.004-.01a1 1 0 0 1 .056-.105 1 1 0 0 1 .105-.133z"/></svg>
@@ -60,6 +60,13 @@ do_common_icons() {
    echo "Working on $filename"
    echo "*  skin/classic/browser/zen-icons/selectable/$filename          (../shared/zen-icons/common/selectable/$filename) " >> jar.inc.mn
  done
  for filename in common/library/*.svg; do
    # remove the os/ prefix
    add_header_to_file $filename
    filename=$(basename $filename)
    echo "Working on $filename"
    echo "*  skin/classic/browser/zen-icons/library/$filename          (../shared/zen-icons/common/library/$filename) " >> jar.inc.mn
  done
 }
 do_icons nucleo WIN    # TODO: use windows icons
@@ -1,5 +1,5 @@
 diff --git a/build/moz.configure/lto-pgo.configure b/build/moz.configure/lto-pgo.configure
-index df2b0bf0081edfdc2c7bccaefc780d2b0c6555ff..53a3b55de7650799e3730372e72ad7b4bb2eea03 100644
+index c72af5ed5f88fc80c810ef626e57a8b991dee514..53a3b55de7650799e3730372e72ad7b4bb2eea03 100644
 --- a/build/moz.configure/lto-pgo.configure
 +++ b/build/moz.configure/lto-pgo.configure
@@ -234,6 +234,7 @@ def moz_pgo_rust(pgo, profile_use, profile_generate, c_compiler):
@@ -14,7 +14,7 @@ index df2b0bf0081edfdc2c7bccaefc780d2b0c6555ff..53a3b55de7650799e3730372e72ad7b4
     help="Indicate that ld64 is free of symbol aliasing bugs",
 )
-imply_option("MOZ_LD64_KNOWN_GOOD", moz_automation)
+-imply_option("MOZ_LD64_KNOWN_GOOD", True, when=moz_automation)
 use_fat_lto = cxx_compiler.try_link(
     ldflags=depends(stlport_libs)(
@@ -1,173 +0,0 @@
 diff --git a/gfx/webrender_bindings/WebRenderAPI.cpp b/gfx/webrender_bindings/WebRenderAPI.cpp
 --- a/gfx/webrender_bindings/WebRenderAPI.cpp
 +++ b/gfx/webrender_bindings/WebRenderAPI.cpp
@@ -298,11 +298,13 @@
                 panic_on_gl_error, picTileWidth, picTileHeight,
                 gfx::gfxVars::WebRenderRequiresHardwareDriver(),
                 StaticPrefs::gfx_webrender_low_quality_pinch_zoom_AtStartup(),
                 StaticPrefs::gfx_webrender_max_shared_surface_size_AtStartup(),
                 StaticPrefs::gfx_webrender_enable_subpixel_aa_AtStartup(),
 -                compositor->ShouldUseLayerCompositor())) {
 +                compositor->ShouldUseLayerCompositor(),
 +                StaticPrefs::
 +                    gfx_webrender_opaque_backdrop_fallback_AtStartup())) {
           // wr_window_new puts a message into gfxCriticalNote if it returns
           // false
           MOZ_ASSERT(errorMessage);
           error.AssignASCII(errorMessage);
           wr_api_free_error_msg(errorMessage);
 diff --git a/gfx/webrender_bindings/src/bindings.rs b/gfx/webrender_bindings/src/bindings.rs
 --- a/gfx/webrender_bindings/src/bindings.rs
 +++ b/gfx/webrender_bindings/src/bindings.rs
@@ -1998,10 +1998,11 @@
     reject_software_rasterizer: bool,
     low_quality_pinch_zoom: bool,
     max_shared_surface_size: i32,
     enable_subpixel_aa: bool,
     use_layer_compositor: bool,
 +    opaque_backdrop_fallback: bool,
 ) -> bool {
     assert!(unsafe { is_in_render_thread() });
     // Ensure the WR profiler callbacks are hooked up to the Gecko profiler.
     set_profiler_hooks(Some(&PROFILER_HOOKS));
@@ -2164,11 +2165,12 @@
         texture_cache_config,
         reject_software_rasterizer,
         low_quality_pinch_zoom,
         max_shared_surface_size,
         enable_dithering,
         enable_shared_instance_buffer,
 +        opaque_backdrop_fallback,
         ..Default::default()
     };
     let window_size = DeviceIntSize::new(window_width, window_height);
     let notifier = Box::new(CppNotifier { window_id });
 diff --git a/gfx/wr/webrender/src/device/gl.rs b/gfx/wr/webrender/src/device/gl.rs
 --- a/gfx/wr/webrender/src/device/gl.rs
 +++ b/gfx/wr/webrender/src/device/gl.rs
@@ -3982,10 +3982,14 @@
     pub fn disable_color_write(&self) {
         self.gl.color_mask(false, false, false, false);
     }
 +    pub fn set_color_mask(&self, r: bool, g: bool, b: bool, a: bool) {
 +        self.gl.color_mask(r, g, b, a);
 +    }
 +
     pub fn set_blend(&mut self, enable: bool) {
         if enable {
             self.gl.enable(gl::BLEND);
         } else {
             self.gl.disable(gl::BLEND);
 diff --git a/gfx/wr/webrender/src/renderer/init.rs b/gfx/wr/webrender/src/renderer/init.rs
 --- a/gfx/wr/webrender/src/renderer/init.rs
 +++ b/gfx/wr/webrender/src/renderer/init.rs
@@ -204,6 +204,8 @@
     pub low_quality_pinch_zoom: bool,
     pub max_shared_surface_size: i32,
     /// If true, open a debug socket to listen for remote debugger.
     /// Relies on `debugger` cargo feature being enabled.
     pub enable_debugger: bool,
 +    /// See explanation of `gfx.webrender.opaque-backdrop-fallback`.
 +    pub opaque_backdrop_fallback: bool,
 }
@@ -277,10 +279,11 @@
             enable_instancing: true,
             enable_shared_instance_buffer: false,
             reject_software_rasterizer: false,
             low_quality_pinch_zoom: false,
             max_shared_surface_size: 2048,
             enable_debugger: true,
 +            opaque_backdrop_fallback: false,
         }
     }
 }
@@ -802,11 +805,12 @@
         allocated_native_surfaces: FastHashSet::default(),
         debug_overlay_state: DebugOverlayState::new(),
         buffer_damage_tracker: BufferDamageTracker::default(),
         max_primitive_instance_count,
         enable_instancing: options.enable_instancing,
         use_shared_instance_buffer,
 +        opaque_backdrop_fallback: options.opaque_backdrop_fallback,
         consecutive_oom_frames: 0,
         target_frame_publish_id: None,
         pending_result_msg: None,
         layer_compositor_frame_state_in_prev_frame: None,
         external_composite_debug_items: Vec::new(),
 diff --git a/gfx/wr/webrender/src/renderer/mod.rs b/gfx/wr/webrender/src/renderer/mod.rs
 --- a/gfx/wr/webrender/src/renderer/mod.rs
 +++ b/gfx/wr/webrender/src/renderer/mod.rs
@@ -867,13 +867,15 @@
     buffer_damage_tracker: BufferDamageTracker,
     max_primitive_instance_count: usize,
     enable_instancing: bool,
     /// If true, stream instance data into large buffers shared by multiple
     /// draws, rather than allocating a new instance buffer for each draw.
     use_shared_instance_buffer: bool,
 +    opaque_backdrop_fallback: bool,
 +
     /// Count consecutive oom frames to detectif we are stuck unable to render
     /// in a loop.
     consecutive_oom_frames: u32,
     /// update() defers processing of ResultMsg, if frame_publish_id of
@@ -2787,18 +2789,29 @@
                 let read_target = ReadTarget::from_texture(cache_texture);
                 // Should always be drawing to picture cache tiles or off-screen surface!
                 debug_assert!(!draw_target.is_default());
                 let device_to_framebuffer = Scale::new(1i32);
 +                let dest_fb_rect = dest * device_to_framebuffer;
                 self.device.blit_render_target(
                     read_target,
                     src * device_to_framebuffer,
                     draw_target,
 -                    dest * device_to_framebuffer,
 +                    dest_fb_rect,
                     TextureFilter::Linear,
                 );
 +
 +                if self.opaque_backdrop_fallback {
 +                    self.device.set_color_mask(false, false, false, true);
 +                    self.device.clear_target(
 +                        Some([0.0, 0.0, 0.0, 1.0]),
 +                        None,
 +                        Some(dest_fb_rect),
 +                    );
 +                    self.device.set_color_mask(true, true, true, true);
 +                }
             }
         }
     }
     fn draw_picture_cache_target(
 diff --git a/modules/libpref/init/StaticPrefList.yaml b/modules/libpref/init/StaticPrefList.yaml
 --- a/modules/libpref/init/StaticPrefList.yaml
 +++ b/modules/libpref/init/StaticPrefList.yaml
@@ -8439,10 +8439,17 @@
 #else
   value: false
 #endif
   mirror: once
 +# Make backdrop-filter treat its captured backdrop as if it had been
 +# composited over an opaque-black background. (See bug 2036640)
 +- name: gfx.webrender.opaque-backdrop-fallback
 +  type: bool
 +  value: true
 +  mirror: once
 +
 # Disable wait of GPU execution completion
 - name: gfx.webrender.wait-gpu-finished.disabled
   type: bool
   value: false
   mirror: once
@@ -0,0 +1,886 @@
 diff --git a/gfx/wr/webrender/src/command_buffer.rs b/gfx/wr/webrender/src/command_buffer.rs
 index 9369cea..8c70d29 100644
 --- a/gfx/wr/webrender/src/command_buffer.rs
 +++ b/gfx/wr/webrender/src/command_buffer.rs
@@ -476,6 +476,9 @@ pub struct CommandBufferBuilder {
     /// List of render tasks that depend on the task that will be created for this builder.
     pub extra_dependencies: Vec<RenderTaskId>,
 +
 +    /// If true, backdrop-filters on this (tiled) surface also read back the slices below it.
 +    pub backdrop_reads_lower_slices: bool,
 }
 impl CommandBufferBuilder {
@@ -485,12 +488,14 @@ impl CommandBufferBuilder {
             establishes_sub_graph: false,
             resolve_source: None,
             extra_dependencies: Vec::new(),
 +            backdrop_reads_lower_slices: false,
         }
     }
     /// Construct a tiled command buffer builder.
     pub fn new_tiled(
         tiles: FastHashMap<TileKey, SurfaceTileDescriptor>,
 +        backdrop_reads_lower_slices: bool,
     ) -> Self {
         CommandBufferBuilder {
             kind: CommandBufferBuilderKind::Tiled {
@@ -499,6 +504,7 @@ impl CommandBufferBuilder {
             establishes_sub_graph: false,
             resolve_source: None,
             extra_dependencies: Vec::new(),
 +            backdrop_reads_lower_slices,
         }
     }
@@ -518,6 +524,7 @@ impl CommandBufferBuilder {
             establishes_sub_graph,
             resolve_source: None,
             extra_dependencies: Vec::new(),
 +            backdrop_reads_lower_slices: false,
         }
     }
 }
 diff --git a/gfx/wr/webrender/src/frame_builder.rs b/gfx/wr/webrender/src/frame_builder.rs
 index 068182d..1442528 100644
 --- a/gfx/wr/webrender/src/frame_builder.rs
 +++ b/gfx/wr/webrender/src/frame_builder.rs
@@ -17,7 +17,7 @@ use crate::gpu_types::{PrimitiveHeaders, ZBufferIdGenerator};
 use crate::gpu_types::QuadSegment;
 use crate::internal_types::{FastHashMap, PlaneSplitter, FrameStamp};
 use crate::invalidation::DirtyRegion;
 -use crate::tile_cache::{SliceId, TileCacheInstance};
 +use crate::tile_cache::{SliceId, TileCacheInstance, update_cross_slice_backdrops};
 use crate::picture::PictureInstance;
 use crate::picture::ResolvedSurfaceTexture;
 use crate::picture::{RasterConfig, PictureScratch};
@@ -487,6 +487,25 @@ impl FrameBuilder {
                 }
             }
 +            if render_picture_cache_slices {
 +                let slice_ids: Vec<SliceId> = scene.tile_cache_pictures
 +                    .iter()
 +                    .filter_map(|pic_index| {
 +                        match scene.prim_store.pictures[pic_index.0 as usize].raster_config {
 +                            Some(RasterConfig { composite_mode: PictureCompositeMode::TileCache { slice_id }, .. }) => Some(slice_id),
 +                            _ => None,
 +                        }
 +                    })
 +                    .collect();
 +
 +                update_cross_slice_backdrops(
 +                    &slice_ids,
 +                    tile_caches,
 +                    &visibility_context,
 +                    &composite_state.compositor_kind,
 +                );
 +            }
 +
             scratch.primitive.frame.assert_draws_resolved();
             profile.end_time(profiler::FRAME_VISIBILITY_TIME);
 diff --git a/gfx/wr/webrender/src/picture.rs b/gfx/wr/webrender/src/picture.rs
 index 9b100ee..8f476e5 100644
 --- a/gfx/wr/webrender/src/picture.rs
 +++ b/gfx/wr/webrender/src/picture.rs
@@ -140,7 +140,8 @@ use std::ops::Range;
 use crate::picture_textures::PictureCacheTextureHandle;
 use crate::util::{MaxRect, Recycler, ScaleOffset};
 use crate::tile_cache::{SliceDebugInfo, TileDebugInfo, DirtyTileDebugInfo, CompositorClipDebugInfo};
 -use crate::tile_cache::{SliceId, TileCacheInstance, TileSurface, NativeSurface};
 +use crate::tile_cache::{SliceId, Tile, TileCacheInstance, TileSurface, NativeSurface};
 +use crate::render_target::{LowerSliceSource, LowerSliceSourceKind};
 use crate::tile_cache::{BackdropKind, BackdropSurface};
 use crate::tile_cache::{TileKey, SubSliceIndex};
 use crate::invalidation::InvalidationReason;
@@ -1660,6 +1661,32 @@ fn prepare_tiled_picture_surface(
     let device_pixel_scale = frame_state
         .surfaces[surface_index.0]
         .device_pixel_scale;
 +
 +    let pic_to_root = if tile_cache.feeds_cross_slice_backdrop {
 +        frame_context.spatial_tree
 +            .get_relative_transform(tile_cache.spatial_node_index, frame_context.root_spatial_node_index)
 +            .as_2d_scale_offset()
 +    } else {
 +        None
 +    };
 +    let rounded_clip = tile_cache.compositor_clip.map(|clip_index| {
 +        let clip = frame_state.composite_state.get_compositor_clip(clip_index);
 +        (clip.rect.cast_unit(), clip.radius)
 +    });
 +    let local_clip_rect = tile_cache.local_clip_rect;
 +    let lower_slice_source = move |tile: &Tile, kind: LowerSliceSourceKind, rect: PictureRect, sub_slice_index: usize| {
 +        let pic_to_root = pic_to_root?;
 +        let clip_rect = local_clip_rect
 +            .intersection(&tile.cached_surface.current_descriptor.local_valid_rect)?;
 +
 +        Some(LowerSliceSource {
 +            kind,
 +            rect: pic_to_root.map_rect(&rect),
 +            clip_rect: pic_to_root.map_rect(&clip_rect),
 +            rounded_clip,
 +            sub_slice_index,
 +        })
 +    };
     let mut at_least_one_tile_visible = false;
     // Get the overall device space rect of the picture cache. Used to clip
@@ -1784,6 +1811,19 @@ fn prepare_tiled_picture_surface(
             at_least_one_tile_visible = true;
 +            if tile.feeds_cross_slice_backdrop {
 +                if let Some(TileSurface::Color { color }) = tile.surface {
 +                    if let Some(source) = lower_slice_source(
 +                        tile,
 +                        LowerSliceSourceKind::Color(color),
 +                        tile.cached_surface.current_descriptor.local_valid_rect,
 +                        sub_slice_index,
 +                    ) {
 +                        frame_state.surface_builder.lower_slice_sources.push(source);
 +                    }
 +                }
 +            }
 +
             if let TileSurface::Texture { descriptor, .. } = tile.surface.as_mut().unwrap() {
                 match descriptor {
                     SurfaceTextureDescriptor::TextureCache { ref handle, .. } => {
@@ -1972,7 +2012,8 @@ fn prepare_tiled_picture_surface(
                     // TODO(gw): As a performance optimization, we could skip the resolve picture
                     //           if the dirty rect is the same as the resolve rect (probably quite
                     //           common for effects that scroll underneath a backdrop-filter, for example).
 -                    let use_tile_composite = !tile.cached_surface.sub_graphs.is_empty();
 +                    let use_tile_composite = !tile.cached_surface.sub_graphs.is_empty() ||
 +                        tile.feeds_cross_slice_backdrop;
                     if use_tile_composite {
                         let mut local_content_rect = tile.cached_surface.local_dirty_rect;
@@ -2056,12 +2097,24 @@ fn prepare_tiled_picture_surface(
                             ),
                         );
 +                        let lower_slice_source = if tile.feeds_cross_slice_backdrop {
 +                            lower_slice_source(
 +                                tile,
 +                                LowerSliceSourceKind::Task(render_task_id),
 +                                (content_device_rect.to_f32() / device_pixel_scale).cast_unit(),
 +                                sub_slice_index,
 +                            )
 +                        } else {
 +                            None
 +                        };
 +
                         surface_render_tasks.insert(
                             tile_key,
                             SurfaceTileDescriptor {
                                 current_task_id: render_task_id,
                                 composite_task_id: Some(composite_task_id),
                                 dirty_rect: tile.cached_surface.local_dirty_rect,
 +                                lower_slice_source,
                             },
                         );
                     } else {
@@ -2097,6 +2150,7 @@ fn prepare_tiled_picture_surface(
                                 current_task_id: render_task_id,
                                 composite_task_id: None,
                                 dirty_rect: tile.cached_surface.local_dirty_rect,
 +                                lower_slice_source: None,
                             },
                         );
                     }
@@ -2262,7 +2316,10 @@ fn prepare_tiled_picture_surface(
             );
     }
 -    let descriptor = SurfaceDescriptor::new_tiled(surface_render_tasks);
 +    let descriptor = SurfaceDescriptor::new_tiled(
 +        surface_render_tasks,
 +        tile_cache.backdrop_reads_lower_slices,
 +    );
     frame_state.surface_builder.push_surface(
         surface_index,
 diff --git a/gfx/wr/webrender/src/render_target.rs b/gfx/wr/webrender/src/render_target.rs
 index 2185365..d3ca780 100644
 --- a/gfx/wr/webrender/src/render_target.rs
 +++ b/gfx/wr/webrender/src/render_target.rs
@@ -4,7 +4,7 @@
 use api::units::*;
 -use api::{ColorF, LineOrientation, BorderStyle};
 +use api::{BorderRadius, ColorF, LineOrientation, BorderStyle};
 use crate::batch::{AlphaBatchBuilder, AlphaBatchContainer, BatchTextures, TextureSet};
 use crate::batch::{BatchBuilder, INVALID_SEGMENT_INDEX, ClipMaskInstanceList};
 use crate::render_task::{SubTask, RectangleClipSubTask, ImageClipSubTask};
@@ -631,6 +631,33 @@ pub struct ResolveOp {
     /// back the region the backdrop actually covers rather than one offset by
     /// the difference between the two raster roots.
     pub dest_to_src_raster: ScaleOffset,
 +    /// Content of the picture cache slices below the backdrop root, drawn bottom-up
 +    /// under the content of the src tasks.
 +    pub lower_slice_sources: Vec<LowerSliceSource>,
 +    /// Maps a rect from the dest surface's raster space into the root coordinate system.
 +    pub dest_raster_to_root: ScaleOffset,
 +}
 +
 +#[cfg_attr(feature = "capture", derive(Serialize))]
 +#[cfg_attr(feature = "replay", derive(Deserialize))]
 +#[derive(Debug, PartialEq, Clone)]
 +pub enum LowerSliceSourceKind {
 +    Task(RenderTaskId),
 +    Color(ColorF),
 +}
 +
 +/// Content of a picture cache tile that a backdrop-filter in a slice above it reads
 +/// back.
 +#[cfg_attr(feature = "capture", derive(Serialize))]
 +#[cfg_attr(feature = "replay", derive(Deserialize))]
 +#[derive(Debug, PartialEq, Clone)]
 +pub struct LowerSliceSource {
 +    pub kind: LowerSliceSourceKind,
 +    /// The rect covered by the task's content, or by the color.
 +    pub rect: LayoutRect,
 +    pub clip_rect: LayoutRect,
 +    pub rounded_clip: Option<(LayoutRect, BorderRadius)>,
 +    pub sub_slice_index: usize,
 }
 #[cfg_attr(feature = "capture", derive(Serialize))]
 diff --git a/gfx/wr/webrender/src/renderer/composite.rs b/gfx/wr/webrender/src/renderer/composite.rs
 index 032a0e1..dd91394 100644
 --- a/gfx/wr/webrender/src/renderer/composite.rs
 +++ b/gfx/wr/webrender/src/renderer/composite.rs
@@ -6,6 +6,7 @@ use api::units::*;
 use api::{ColorF, ImageBufferKind, ImageRendering, PremultipliedColorF};
 use crate::batch::BatchTextures;
 use crate::composite::{
 +    CompositorClip,
     CompositeState, CompositeSurfaceFormat, CompositeTileSurface, CompositorConfig,
     CompositorInputLayer, CompositorSurfaceUsage, CompositorSurfaceTransform,
     CompositeRoundedCorner, NativeTileId, ResolvedExternalSurface,
@@ -20,7 +21,11 @@ use crate::debug_item::DebugItem;
 use crate::segment::EdgeMask;
 use crate::device::DrawTarget;
 use crate::gpu_types::{CompositeInstance, ZBufferId};
 -use crate::internal_types::{FastHashMap, TextureSource};
 +use crate::internal_types::{FastHashMap, Swizzle, TextureSource};
 +use crate::render_target::{LowerSliceSourceKind, ResolveOp};
 +use crate::render_task::RenderTaskKind;
 +use crate::render_task_graph::RenderTaskGraph;
 +use api::BorderRadius;
 use crate::picture::ResolvedSurfaceTexture;
 use super::RenderResults;
 use crate::profiler::{self};
@@ -435,6 +440,134 @@ impl Renderer {
         }
     }
 +    pub(super) fn draw_resolve_with_lower_slices(
 +        &mut self,
 +        resolve_op: &ResolveOp,
 +        render_tasks: &RenderTaskGraph,
 +        draw_target: DrawTarget,
 +        projection: &default::Transform3D<f32>,
 +        src_copies: &[(TextureSource, DeviceIntRect, DeviceIntRect)],
 +        stats: &mut RendererStats,
 +    ) {
 +        let dest_task = &render_tasks[resolve_op.dest_task_id];
 +        let dest_info = match dest_task.kind {
 +            RenderTaskKind::Picture(ref info) => info,
 +            _ => panic!("bug: not a picture"),
 +        };
 +        let dest_task_rect = DeviceRect::from_origin_and_size(
 +            dest_task.get_target_rect().min.to_f32(),
 +            dest_info.content_size.to_f32(),
 +        );
 +        let dest_offset = dest_task_rect.min.to_vector() - dest_info.content_origin.to_vector();
 +        let root_to_dest = |rect: &LayoutRect| -> DeviceRect {
 +            let raster: WorldRect = resolve_op.dest_raster_to_root.unmap_rect(rect);
 +            let device: DeviceRect = (raster * dest_info.device_pixel_scale).cast_unit();
 +            device.translate(dest_offset)
 +        };
 +        let radius_scale = dest_info.device_pixel_scale.0 / resolve_op.dest_raster_to_root.scale.x;
 +
 +        let mut draws = Vec::new();
 +
 +        for source in &resolve_op.lower_slice_sources {
 +            let clip_rect = match root_to_dest(&source.clip_rect).intersection(&dest_task_rect) {
 +                Some(clip_rect) => clip_rect,
 +                None => continue,
 +            };
 +            let rect = root_to_dest(&source.rect);
 +            let clip = source.rounded_clip.map(|(clip_rect, radius)| {
 +                CompositorClip {
 +                    rect: root_to_dest(&clip_rect),
 +                    radius: BorderRadius {
 +                        top_left: radius.top_left * radius_scale,
 +                        top_right: radius.top_right * radius_scale,
 +                        bottom_left: radius.bottom_left * radius_scale,
 +                        bottom_right: radius.bottom_right * radius_scale,
 +                        ..radius
 +                    },
 +                }
 +            });
 +
 +            match source.kind {
 +                LowerSliceSourceKind::Task(task_id) => {
 +                    let task = &render_tasks[task_id];
 +                    let texture = TextureSource::TextureCache(task.get_target_texture(), Swizzle::default());
 +                    let uv_rect = task.get_target_rect().to_f32();
 +                    let instance = CompositeInstance::new_rgb(
 +                        rect,
 +                        clip_rect,
 +                        PremultipliedColorF::WHITE,
 +                        TexelRect::new(uv_rect.min.x, uv_rect.min.y, uv_rect.max.x, uv_rect.max.y),
 +                        false,
 +                        (false, false),
 +                        clip.as_ref(),
 +                    );
 +                    let texture_size = self.texture_resolver.get_texture_size(&texture).to_f32();
 +                    draws.push((instance, texture, Some(texture_size)));
 +                }
 +                LowerSliceSourceKind::Color(color) => {
 +                    let instance = CompositeInstance::new(
 +                        rect,
 +                        clip_rect,
 +                        color.premultiplied(),
 +                        (false, false),
 +                        clip.as_ref(),
 +                    );
 +                    draws.push((instance, TextureSource::Dummy, None));
 +                }
 +            }
 +        }
 +
 +        for (texture, src, dest) in src_copies {
 +            let dest = dest.to_f32();
 +            let src = src.to_f32();
 +            let instance = CompositeInstance::new_rgb(
 +                dest,
 +                dest,
 +                PremultipliedColorF::WHITE,
 +                TexelRect::new(src.min.x, src.min.y, src.max.x, src.max.y),
 +                false,
 +                (false, false),
 +                None,
 +            );
 +            let texture_size = self.texture_resolver.get_texture_size(texture).to_f32();
 +            draws.push((instance, *texture, Some(texture_size)));
 +        }
 +
 +        self.device.bind_draw_target(draw_target);
 +        self.device.disable_depth();
 +        self.device.disable_depth_write();
 +        self.set_blend(true, FramebufferKind::Other);
 +        self.set_blend_mode_premultiplied_alpha(FramebufferKind::Other);
 +
 +        for (instance, texture, texture_size) in draws {
 +            let features = instance.get_rgb_features();
 +
 +            self.shaders
 +                .borrow_mut()
 +                .get_composite_shader(
 +                    CompositeSurfaceFormat::Rgba,
 +                    texture.image_buffer_kind(),
 +                    features,
 +                ).bind(
 +                    &mut self.device,
 +                    projection,
 +                    texture_size,
 +                    &mut self.renderer_errors,
 +                    &mut self.profile,
 +                    &mut self.command_log,
 +                );
 +
 +            self.draw_instanced_batch(
 +                &[instance],
 +                VertexArrayKind::Composite,
 +                &BatchTextures::composite_rgb(texture),
 +                stats,
 +            );
 +        }
 +
 +        self.set_blend(false, FramebufferKind::Other);
 +    }
 +
     // Composite tiles in a swapchain. When using LayerCompositor, we may
     // split the compositing in to multiple swapchains.
     fn composite_pass(
 diff --git a/gfx/wr/webrender/src/renderer/mod.rs b/gfx/wr/webrender/src/renderer/mod.rs
 index d177263..a45ec70 100644
 --- a/gfx/wr/webrender/src/renderer/mod.rs
 +++ b/gfx/wr/webrender/src/renderer/mod.rs
@@ -2288,6 +2288,8 @@ impl Renderer {
         resolve_ops: &[ResolveOp],
         render_tasks: &RenderTaskGraph,
         draw_target: DrawTarget,
 +        projection: &default::Transform3D<f32>,
 +        stats: &mut RendererStats,
     ) {
         if resolve_ops.is_empty() {
             return;
@@ -2300,6 +2302,8 @@ impl Renderer {
                 resolve_op,
                 render_tasks,
                 draw_target,
 +                projection,
 +                stats,
             );
         }
@@ -2729,7 +2733,12 @@ impl Renderer {
         resolve_op: &ResolveOp,
         render_tasks: &RenderTaskGraph,
         draw_target: DrawTarget,
 +        projection: &default::Transform3D<f32>,
 +        stats: &mut RendererStats,
     ) {
 +        let has_lower_slices = !resolve_op.lower_slice_sources.is_empty();
 +        let mut src_copies = Vec::new();
 +
         for src_task_id in &resolve_op.src_task_ids {
             let src_task = &render_tasks[*src_task_id];
             let src_info = match src_task.kind {
@@ -2818,6 +2827,12 @@ impl Renderer {
                     src_task.get_target_texture(),
                     Swizzle::default(),
                 );
 +
 +                if has_lower_slices {
 +                    src_copies.push((texture_source, src, dest));
 +                    continue;
 +                }
 +
                 let (cache_texture, _) = self.texture_resolver
                     .resolve(&texture_source).expect("bug: no source texture");
@@ -2836,6 +2851,17 @@ impl Renderer {
                 );
             }
         }
 +
 +        if has_lower_slices {
 +            self.draw_resolve_with_lower_slices(
 +                resolve_op,
 +                render_tasks,
 +                draw_target,
 +                projection,
 +                &src_copies,
 +                stats,
 +            );
 +        }
     }
     fn draw_picture_cache_target(
@@ -3385,6 +3411,8 @@ impl Renderer {
             &target.resolve_ops,
             render_tasks,
             draw_target,
 +            &projection,
 +            stats,
         );
         // Handle any blits from the texture cache to this target.
 diff --git a/gfx/wr/webrender/src/surface.rs b/gfx/wr/webrender/src/surface.rs
 index 20536bb..f8a8709 100644
 --- a/gfx/wr/webrender/src/surface.rs
 +++ b/gfx/wr/webrender/src/surface.rs
@@ -14,7 +14,7 @@ use crate::picture_composite_mode::PictureCompositeMode;
 use crate::tile_cache::{TileKey, SubSliceIndex, MAX_COMPOSITOR_SURFACES};
 use crate::prim_store::PictureIndex;
 use crate::render_task_graph::{RenderTaskId, RenderTaskGraphBuilder};
 -use crate::render_target::ResolveOp;
 +use crate::render_target::{LowerSliceSource, LowerSliceSourceKind, ResolveOp};
 use crate::render_task::{RenderTask, RenderTaskKind, RenderTaskLocation};
 use crate::space::SpaceMapper;
 use crate::spatial_tree::{CoordinateSpaceMapping, SpatialTree, SpatialNodeIndex};
@@ -380,6 +380,8 @@ pub struct SurfaceTileDescriptor {
     pub composite_task_id: Option<RenderTaskId>,
     /// Dirty rect for this tile
     pub dirty_rect: PictureRect,
 +    /// Set if this tile's content is read back by a backdrop-filter in a slice above.
 +    pub lower_slice_source: Option<LowerSliceSource>,
 }
 // Details of how a surface is rendered
@@ -387,6 +389,7 @@ pub enum SurfaceDescriptorKind {
     // Picture cache tiles
     Tiled {
         tiles: FastHashMap<TileKey, SurfaceTileDescriptor>,
 +        backdrop_reads_lower_slices: bool,
     },
     // A single surface (e.g. for an opacity filter)
     Simple {
@@ -410,10 +413,12 @@ impl SurfaceDescriptor {
     // Create a picture cache tiled surface
     pub fn new_tiled(
         tiles: FastHashMap<TileKey, SurfaceTileDescriptor>,
 +        backdrop_reads_lower_slices: bool,
     ) -> Self {
         SurfaceDescriptor {
             kind: SurfaceDescriptorKind::Tiled {
                 tiles,
 +                backdrop_reads_lower_slices,
             },
         }
     }
@@ -526,6 +531,9 @@ pub struct SurfaceBuilder {
     // A map of the output render tasks from any sub-graphs that haven't
     // been consumed by BackdropRender prims yet
     pub sub_graph_output_map: FastHashMap<PictureIndex, RenderTaskId>,
 +    // Content of the picture cache slices built so far that backdrop-filters in
 +    // slices above them read back, ordered bottom-up
 +    pub lower_slice_sources: Vec<LowerSliceSource>,
 }
 impl SurfaceBuilder {
@@ -534,6 +542,7 @@ impl SurfaceBuilder {
             current_cmd_buffers: CommandBufferTargets::new(),
             builder_stack: Vec::new(),
             sub_graph_output_map: FastHashMap::default(),
 +            lower_slice_sources: Vec::new(),
         }
     }
@@ -574,9 +583,10 @@ impl SurfaceBuilder {
         let builder = if let Some(descriptor) = descriptor {
             match descriptor.kind {
 -                SurfaceDescriptorKind::Tiled { tiles } => {
 +                SurfaceDescriptorKind::Tiled { tiles, backdrop_reads_lower_slices } => {
                     CommandBufferBuilder::new_tiled(
                         tiles,
 +                        backdrop_reads_lower_slices,
                     )
                 }
                 SurfaceDescriptorKind::Simple { render_task_id, dirty_rect, .. } => {
@@ -700,6 +710,7 @@ impl SurfaceBuilder {
                     // Get info about the resolve operation to copy from parent surface or tiles to the picture cache task
                     if let Some(resolve_task_id) = builder.resolve_source {
                         let mut src_task_ids = Vec::new();
 +                        let reads_lower_slices = self.builder_stack.last().unwrap().backdrop_reads_lower_slices;
                         // Make the output of the sub-graph a dependency of the new replacement tile task
                         let _old = self.sub_graph_output_map.insert(
@@ -869,6 +880,27 @@ impl SurfaceBuilder {
                             &src_task_ids,
                         );
 +                        let mut lower_slice_sources = Vec::new();
 +                        let mut dest_raster_to_root = ScaleOffset::identity();
 +
 +                        if reads_lower_slices && !self.lower_slice_sources.is_empty() {
 +                            let dest_raster = raster_spatial_node(rg_builder, resolve_task_id);
 +                            let to_root = spatial_tree
 +                                .get_relative_transform(dest_raster, spatial_tree.root_reference_frame_index())
 +                                .as_2d_scale_offset();
 +
 +                            if let Some(to_root) = to_root {
 +                                dest_raster_to_root = to_root;
 +                                lower_slice_sources = self.lower_slice_sources.clone();
 +
 +                                for source in &lower_slice_sources {
 +                                    if let LowerSliceSourceKind::Task(task_id) = source.kind {
 +                                        rg_builder.add_dependency(resolve_task_id, task_id);
 +                                    }
 +                                }
 +                            }
 +                        }
 +
                         let dest_task = rg_builder.get_task_mut(resolve_task_id);
                         match dest_task.kind {
@@ -878,6 +910,8 @@ impl SurfaceBuilder {
                                     src_task_ids,
                                     dest_task_id: resolve_task_id,
                                     dest_to_src_raster,
 +                                    lower_slice_sources,
 +                                    dest_raster_to_root,
                                 })
                             }
                             _ => {
@@ -917,7 +951,16 @@ impl SurfaceBuilder {
         } else {
             match builder.kind {
                 CommandBufferBuilderKind::Tiled { ref tiles } => {
 +                    let first_source = self.lower_slice_sources.len();
 +
                     for (_, descriptor) in tiles {
 +                        if let Some(ref source) = descriptor.lower_slice_source {
 +                            self.lower_slice_sources.push(LowerSliceSource {
 +                                kind: LowerSliceSourceKind::Task(descriptor.current_task_id),
 +                                ..source.clone()
 +                            });
 +                        }
 +
                         if let Some(composite_task_id) = descriptor.composite_task_id {
                             rg_builder.add_dependency(
                                 composite_task_id,
@@ -933,6 +976,8 @@ impl SurfaceBuilder {
                             }
                         }
                     }
 +
 +                    self.lower_slice_sources[first_source ..].sort_by_key(|source| source.sub_slice_index);
                 }
                 CommandBufferBuilderKind::Simple { render_task_id: child_task_id, root_task_id: child_root_task_id, .. } => {
                     match self.builder_stack.last().unwrap().kind {
 diff --git a/gfx/wr/webrender/src/tile_cache/mod.rs b/gfx/wr/webrender/src/tile_cache/mod.rs
 index 731be26..d20e6ac 100644
 --- a/gfx/wr/webrender/src/tile_cache/mod.rs
 +++ b/gfx/wr/webrender/src/tile_cache/mod.rs
@@ -198,6 +198,8 @@ pub struct TileCacheParams {
     // This is only a suggestion - the tile cache will clamp this as a reasonable number
     // and only promote a limited number of surfaces.
     pub yuv_image_surface_count: usize,
 +    // If true, backdrop-filters in this slice also read back content from the slices below it.
 +    pub backdrop_reads_lower_slices: bool,
 }
 /// The backing surface for this tile.
@@ -250,6 +252,8 @@ pub struct Tile {
     pub cached_surface: CachedSurface,
     /// Raster-space rect for this tile, cached to avoid recomputing per primitive.
     pub local_raster_rect: RasterRect,
 +    /// If true, this tile is read back this frame by a slice above.
 +    pub feeds_cross_slice_backdrop: bool,
 }
 impl Tile {
@@ -269,6 +273,7 @@ impl Tile {
             z_id: ZBufferId::invalid(),
             cached_surface: CachedSurface::new(),
             local_raster_rect: RasterRect::zero(),
 +            feeds_cross_slice_backdrop: false,
         }
     }
@@ -828,6 +833,15 @@ pub struct TileCacheInstance {
     pub yuv_images_remaining: usize,
     /// Persistent cache for computing and storing raster-space primitive corners.
     corners_cache: CornersCache,
 +    /// If true, backdrop-filters in this slice also read back content from the slices below it.
 +    pub backdrop_reads_lower_slices: bool,
 +    /// The picture-space coverage rects of the backdrop-filters found in this slice this frame.
 +    backdrop_render_rects: Vec<PictureRect>,
 +    /// The picture to root transform of this slice in the previous frame, used to detect
 +    /// movement relative to backdrop-filters in slices above.
 +    prev_pic_to_root: Option<ScaleOffset>,
 +    /// If true, some tiles of this slice are read back by a backdrop-filter in a slice above.
 +    pub feeds_cross_slice_backdrop: bool,
 }
 impl TileCacheInstance {
@@ -893,6 +907,10 @@ impl TileCacheInstance {
             yuv_images_count: params.yuv_image_surface_count,
             yuv_images_remaining: 0,
             corners_cache: CornersCache::new(),
 +            backdrop_reads_lower_slices: params.backdrop_reads_lower_slices,
 +            backdrop_render_rects: Vec::new(),
 +            prev_pic_to_root: None,
 +            feeds_cross_slice_backdrop: false,
         }
     }
@@ -970,6 +988,7 @@ impl TileCacheInstance {
         self.background_color = params.background_color;
         self.shared_clip_leaf_id = params.shared_clip_leaf_id;
         self.shared_clip_node_id = params.shared_clip_node_id;
 +        self.backdrop_reads_lower_slices = params.backdrop_reads_lower_slices;
         // Since the slice flags may have changed, ensure we re-evaluate the
         // appropriate tile size for this cache next update.
@@ -1040,6 +1059,7 @@ impl TileCacheInstance {
         self.local_rect = pic_rect;
         self.local_clip_rect = PictureRect::max_rect();
         self.deferred_dirty_tests.clear();
 +        self.backdrop_render_rects.clear();
         self.mix_blend_pic_rects.clear();
         self.underlays.clear();
         self.overlay_region = PictureRect::zero();
@@ -2667,6 +2687,8 @@ impl TileCacheInstance {
                         }
                     }
 +                    self.backdrop_render_rects.push(pic_coverage_rect);
 +
                     // For backdrop-filter, we need to check if any of the dirty rects
                     // in tiles that are affected by the filter primitive are dirty.
                     self.deferred_dirty_tests.push(DeferredDirtyTest {
@@ -3264,6 +3286,159 @@ impl TileCacheInstance {
 }
 +fn slice_is_dirty_in_rect(tile_cache: &TileCacheInstance, rect: &PictureRect) -> bool {
 +    tile_cache.sub_slices.iter().any(|sub_slice| {
 +        sub_slice.tiles.values().any(|tile| {
 +            tile.is_visible &&
 +            !tile.cached_surface.is_valid &&
 +            tile.cached_surface.local_dirty_rect.intersects(rect)
 +        })
 +    })
 +}
 +
 +fn invalidate_slice_rect(
 +    tile_cache: &mut TileCacheInstance,
 +    rect: &PictureRect,
 +    supports_dirty_rects: bool,
 +    feeds_cross_slice_backdrop: bool,
 +) {
 +    let mut rects = vec![*rect];
 +
 +    rects.extend(
 +        tile_cache.backdrop_render_rects
 +            .iter()
 +            .filter(|backdrop_rect| backdrop_rect.intersects(rect))
 +            .cloned()
 +    );
 +
 +    for sub_slice in &mut tile_cache.sub_slices {
 +        for tile in sub_slice.tiles.values_mut() {
 +            if !tile.is_visible {
 +                continue;
 +            }
 +
 +            for rect in &rects {
 +                if !tile.cached_surface.local_rect.intersects(rect) {
 +                    continue;
 +                }
 +
 +                tile.invalidate(Some(*rect), InvalidationReason::SurfaceContentChanged);
 +                if !supports_dirty_rects {
 +                    tile.cached_surface.local_dirty_rect = tile.cached_surface.local_rect;
 +                }
 +                tile.feeds_cross_slice_backdrop |= feeds_cross_slice_backdrop;
 +                tile_cache.feeds_cross_slice_backdrop |= feeds_cross_slice_backdrop;
 +            }
 +        }
 +    }
 +}
 +
 +pub fn update_cross_slice_backdrops(
 +    slice_ids: &[SliceId],
 +    tile_caches: &mut FastHashMap<SliceId, Box<TileCacheInstance>>,
 +    frame_context: &FrameVisibilityContext,
 +    compositor_kind: &CompositorKind,
 +) {
 +    let supports_dirty_rects = match compositor_kind {
 +        CompositorKind::Draw { .. } | CompositorKind::Layer { .. } => {
 +            frame_context.config.gpu_supports_render_target_partial_update
 +        }
 +        CompositorKind::Native { capabilities, .. } => {
 +            capabilities.max_update_rects > 0
 +        }
 +    };
 +
 +    let any_backdrop = slice_ids.iter().any(|slice_id| {
 +        let tile_cache = &tile_caches[slice_id];
 +        tile_cache.backdrop_reads_lower_slices && !tile_cache.backdrop_render_rects.is_empty()
 +    });
 +
 +    let mut pic_to_root = Vec::with_capacity(slice_ids.len());
 +    let mut moved = Vec::with_capacity(slice_ids.len());
 +
 +    for slice_id in slice_ids {
 +        let tile_cache = tile_caches.get_mut(slice_id).expect("bug: non-existent tile cache");
 +
 +        if tile_cache.feeds_cross_slice_backdrop {
 +            tile_cache.feeds_cross_slice_backdrop = false;
 +            for sub_slice in &mut tile_cache.sub_slices {
 +                for tile in sub_slice.tiles.values_mut() {
 +                    tile.feeds_cross_slice_backdrop = false;
 +                }
 +            }
 +        }
 +
 +        if !any_backdrop {
 +            tile_cache.prev_pic_to_root = None;
 +            continue;
 +        }
 +
 +        let transform = frame_context.spatial_tree
 +            .get_relative_transform(tile_cache.spatial_node_index, frame_context.root_spatial_node_index)
 +            .as_2d_scale_offset();
 +
 +        moved.push(transform != tile_cache.prev_pic_to_root);
 +        tile_cache.prev_pic_to_root = transform;
 +        pic_to_root.push(transform);
 +    }
 +
 +    if !any_backdrop {
 +        return;
 +    }
 +
 +    for top in 1 .. slice_ids.len() {
 +        let top_transform = match pic_to_root[top] {
 +            Some(transform) => transform,
 +            None => continue,
 +        };
 +
 +        let backdrop_rects = {
 +            let tile_cache = &tile_caches[&slice_ids[top]];
 +            if !tile_cache.backdrop_reads_lower_slices {
 +                continue;
 +            }
 +            tile_cache.backdrop_render_rects.clone()
 +        };
 +
 +        for backdrop_rect in backdrop_rects {
 +            let root_rect: LayoutRect = top_transform.map_rect(&backdrop_rect);
 +
 +            let lower_rects: Vec<(usize, PictureRect)> = (0 .. top)
 +                .filter_map(|lower| {
 +                    let rect: PictureRect = pic_to_root[lower]?.unmap_rect(&root_rect);
 +                    Some((lower, rect))
 +                })
 +                .collect();
 +
 +            let needs_update = moved[top] ||
 +                slice_is_dirty_in_rect(&tile_caches[&slice_ids[top]], &backdrop_rect) ||
 +                lower_rects.iter().any(|(lower, rect)| {
 +                    moved[*lower] || slice_is_dirty_in_rect(&tile_caches[&slice_ids[*lower]], rect)
 +                });
 +
 +            if !needs_update {
 +                continue;
 +            }
 +
 +            invalidate_slice_rect(
 +                tile_caches.get_mut(&slice_ids[top]).unwrap(),
 +                &backdrop_rect,
 +                supports_dirty_rects,
 +                false,
 +            );
 +
 +            for (lower, rect) in lower_rects {
 +                invalidate_slice_rect(
 +                    tile_caches.get_mut(&slice_ids[lower]).unwrap(),
 +                    &rect,
 +                    supports_dirty_rects,
 +                    true,
 +                );
 +            }
 +        }
 +    }
 +}
 +
 /// A SubSlice represents a potentially overlapping set of tiles within a picture cache. Most
 /// picture cache instances will have only a single sub-slice. The exception to this is when
 /// a picture cache has compositor surfaces, in which case sub slices are used to interleave
 diff --git a/gfx/wr/webrender/src/tile_cache/slice_builder.rs b/gfx/wr/webrender/src/tile_cache/slice_builder.rs
 index f81edc9..d8759bc 100644
 --- a/gfx/wr/webrender/src/tile_cache/slice_builder.rs
 +++ b/gfx/wr/webrender/src/tile_cache/slice_builder.rs
@@ -688,6 +688,7 @@ fn create_tile_cache(
         virtual_surface_size: frame_builder_config.compositor_kind.get_virtual_surface_size(),
         image_surface_count: prim_list.image_surface_count,
         yuv_image_surface_count: prim_list.yuv_image_surface_count,
 +        backdrop_reads_lower_slices: iframe_clip.is_none() && slice > 0,
     });
     let pic_index = prim_store.pictures.alloc().init(PictureInstance::new_image(
@@ -1,168 +0,0 @@
 diff --git a/browser/components/sessionstore/test/browser.toml b/browser/components/sessionstore/test/browser.toml
 --- a/browser/components/sessionstore/test/browser.toml
 +++ b/browser/components/sessionstore/test/browser.toml
@@ -14,10 +14,12 @@
   "browser_frame_history_c.html",
   "browser_frame_history_c1.html",
   "browser_frame_history_c2.html",
   "browser_formdata_format_sample.html",
   "browser_sessionHistory_slow.sjs",
 +  "browser_policy_container_sample.html",
 +  "browser_policy_container_sample_frame.html",
   "browser_scrollPositions_sample.html",
   "browser_scrollPositions_sample2.html",
   "browser_scrollPositions_sample_frameset.html",
   "browser_scrollPositions_readerModeArticle.html",
   "browser_sessionStorage.html",
@@ -226,10 +228,12 @@
 ["browser_pinned_tabs.js"]
 skip-if = [
   "ccov", # Bug 1625525
 ]
 +["browser_policy_container_not_stored.js"]
 +
 ["browser_privatetabs.js"]
 ["browser_purge_domaindata.js"]
 ["browser_purge_shistory.js"]
 diff --git a/browser/components/sessionstore/test/browser_policy_container_not_stored.js b/browser/components/sessionstore/test/browser_policy_container_not_stored.js
 new file mode 100644
 --- /dev/null
 +++ b/browser/components/sessionstore/test/browser_policy_container_not_stored.js
@@ -0,0 +1,51 @@
 +/* This Source Code Form is subject to the terms of the Mozilla Public
 + * License, v. 2.0. If a copy of the MPL was not distributed with this
 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 +
 +"use strict";
 +
 +/**
 + * A session history entry only needs to retain the policy container for loads
 + * that inherit their policies (about:blank, about:srcdoc, blob:, data:, ...).
 + * Anything fetched over the network gets its policies from the response again,
 + * so storing them would only bloat the session store (bug 2011236).
 + */
 +
 +const TEST_ROOT = getRootDirectory(gTestPath).replace(
 +  "chrome://mochitests/content",
 +  "https://example.com"
 +);
 +const PARENT_URL = TEST_ROOT + "browser_policy_container_sample.html";
 +const FRAME_URL = TEST_ROOT + "browser_policy_container_sample_frame.html";
 +
 +add_task(async function test_policy_container_only_for_inheriting_loads() {
 +  const tab = BrowserTestUtils.addTab(gBrowser, PARENT_URL);
 +  gBrowser.selectedTab = tab;
 +  await promiseBrowserLoaded(tab.linkedBrowser, true, PARENT_URL);
 +  await TabStateFlusher.flush(tab.linkedBrowser);
 +
 +  const state = JSON.parse(ss.getTabState(tab));
 +  const topEntry = state.entries.at(-1);
 +  is(topEntry.url, PARENT_URL, "collected the parent entry");
 +
 +  const children = topEntry.children ?? [];
 +  const networkFrame = children.find(child => child.url === FRAME_URL);
 +  const blankFrame = children.find(child => child.url === "about:blank");
 +
 +  ok(networkFrame, "collected the network-scheme subframe entry");
 +  ok(blankFrame, "collected the about:blank subframe entry");
 +
 +  // The parent has a CSP, so both subframes inherit a policy container onto
 +  // their load state. Only the one that cannot recover it from a response
 +  // should keep it in session history.
 +  ok(
 +    !("policyContainer" in networkFrame),
 +    "https subframe entry does not store a policyContainer"
 +  );
 +  ok(
 +    "policyContainer" in blankFrame,
 +    "about:blank subframe entry still stores its inherited policyContainer"
 +  );
 +
 +  await BrowserTestUtils.removeTab(tab);
 +});
 diff --git a/browser/components/sessionstore/test/browser_policy_container_sample.html b/browser/components/sessionstore/test/browser_policy_container_sample.html
 new file mode 100644
 --- /dev/null
 +++ b/browser/components/sessionstore/test/browser_policy_container_sample.html
@@ -0,0 +1,12 @@
 +<!DOCTYPE html>
 +<html>
 +<head>
 +  <meta charset="utf-8">
 +  <meta http-equiv="Content-Security-Policy" content="default-src * data: blob: 'unsafe-inline'">
 +  <title>policyContainer session store sample</title>
 +</head>
 +<body>
 +  <iframe id="network" src="browser_policy_container_sample_frame.html"></iframe>
 +  <iframe id="blank" src="about:blank"></iframe>
 +</body>
 +</html>
 diff --git a/browser/components/sessionstore/test/browser_policy_container_sample_frame.html b/browser/components/sessionstore/test/browser_policy_container_sample_frame.html
 new file mode 100644
 --- /dev/null
 +++ b/browser/components/sessionstore/test/browser_policy_container_sample_frame.html
@@ -0,0 +1,10 @@
 +<!DOCTYPE html>
 +<html>
 +<head>
 +  <meta charset="utf-8">
 +  <title>policyContainer session store sample frame</title>
 +</head>
 +<body>
 +  frame
 +</body>
 +</html>
 diff --git a/docshell/shistory/SessionHistoryEntry.cpp b/docshell/shistory/SessionHistoryEntry.cpp
 --- a/docshell/shistory/SessionHistoryEntry.cpp
 +++ b/docshell/shistory/SessionHistoryEntry.cpp
@@ -41,10 +41,18 @@
 extern mozilla::LazyLogModule gSHLog;
 namespace mozilla {
 namespace dom {
 +// Only store policy container for loads that can't carry it themselves
 +// (about:blank, about:srcdoc, blob:, data:, ...)
 +// bug 1867137, bug 2011236
 +static nsIPolicyContainer* PolicyContainerToStore(
 +    nsIURI* aURI, nsIPolicyContainer* aPolicyContainer) {
 +  return CSP_ShouldURIInheritCSP(aURI) ? aPolicyContainer : nullptr;
 +}
 +
 SessionHistoryInfo::SessionHistoryInfo(nsDocShellLoadState* aLoadState,
                                        nsIChannel* aChannel)
     : mURI(aLoadState->URI()),
       mOriginalURI(aLoadState->OriginalURI()),
       mResultPrincipalURI(aLoadState->ResultPrincipalURI()),
@@ -59,11 +67,12 @@
       mLoadReplace(aLoadState->LoadReplace()),
       mHasUserActivation(aLoadState->HasValidUserGestureActivation()),
       mSharedState(SharedState::Create(
           aLoadState->TriggeringPrincipal(), aLoadState->PrincipalToInherit(),
           aLoadState->PartitionedPrincipalToInherit(),
 -          aLoadState->PolicyContainer(),
 +          PolicyContainerToStore(aLoadState->URI(),
 +                                 aLoadState->PolicyContainer()),
           /* FIXME Is this correct? */
           aLoadState->TypeHint())) {
   MOZ_DIAGNOSTIC_ASSERT(!mURI->SchemeIs("javascript"));
   // Pull the upload stream off of the channel instead of the load state, as
@@ -124,11 +133,12 @@
   loadInfo->GetPrincipalToInherit(
       getter_AddRefs(mSharedState.Get()->mPrincipalToInherit));
   mSharedState.Get()->mPartitionedPrincipalToInherit =
       aPartitionedPrincipalToInherit;
 -  mSharedState.Get()->mPolicyContainer = aPolicyContainer;
 +  mSharedState.Get()->mPolicyContainer =
 +      PolicyContainerToStore(mURI, aPolicyContainer);
   aChannel->GetContentType(mSharedState.Get()->mContentType);
   aChannel->GetOriginalURI(getter_AddRefs(mOriginalURI));
   uint32_t loadFlags;
   aChannel->GetLoadFlags(&loadFlags);
@@ -0,0 +1,131 @@
 diff --git a/toolkit/modules/subprocess/subprocess_shared_unix.js b/toolkit/modules/subprocess/subprocess_shared_unix.js
 --- a/toolkit/modules/subprocess/subprocess_shared_unix.js
 +++ b/toolkit/modules/subprocess/subprocess_shared_unix.js
@@ -57,11 +57,11 @@
   fcntl: [
     ctypes.default_abi,
     ctypes.int,
     ctypes.int /* fildes */,
     ctypes.int /* cmd */,
 -    ctypes.int /* ... */,
 +    "...",
   ],
   getcwd: [
     ctypes.default_abi,
     ctypes.char.ptr,
 diff --git a/toolkit/modules/subprocess/subprocess_unix.sys.mjs b/toolkit/modules/subprocess/subprocess_unix.sys.mjs
 --- a/toolkit/modules/subprocess/subprocess_unix.sys.mjs
 +++ b/toolkit/modules/subprocess/subprocess_unix.sys.mjs
@@ -34,13 +34,13 @@
       throw new Error("Unable to create pipe");
     }
     this.signalFd = fds[1];
 -    libc.fcntl(fds[0], LIBC.F_SETFL, LIBC.O_NONBLOCK);
 -    libc.fcntl(fds[0], LIBC.F_SETFD, LIBC.FD_CLOEXEC);
 -    libc.fcntl(fds[1], LIBC.F_SETFD, LIBC.FD_CLOEXEC);
 +    libc.fcntl(fds[0], LIBC.F_SETFL, ctypes.int(LIBC.O_NONBLOCK));
 +    libc.fcntl(fds[0], LIBC.F_SETFD, ctypes.int(LIBC.FD_CLOEXEC));
 +    libc.fcntl(fds[1], LIBC.F_SETFD, ctypes.int(LIBC.FD_CLOEXEC));
     this.call("init", [{ signalFd: fds[0] }]);
   }
   closePipe() {
 diff --git a/toolkit/modules/subprocess/subprocess_unix.worker.js b/toolkit/modules/subprocess/subprocess_unix.worker.js
 --- a/toolkit/modules/subprocess/subprocess_unix.worker.js
 +++ b/toolkit/modules/subprocess/subprocess_unix.worker.js
@@ -349,13 +349,13 @@
         our_pipes.push(new InputPipe(this, fds[1]));
       } else {
         our_pipes.push(new OutputPipe(this, fds[1]));
       }
 -      libc.fcntl(fds[0], LIBC.F_SETFD, LIBC.FD_CLOEXEC);
 -      libc.fcntl(fds[1], LIBC.F_SETFD, LIBC.FD_CLOEXEC);
 -      libc.fcntl(fds[1], LIBC.F_SETFL, LIBC.O_NONBLOCK);
 +      libc.fcntl(fds[0], LIBC.F_SETFD, ctypes.int(LIBC.FD_CLOEXEC));
 +      libc.fcntl(fds[1], LIBC.F_SETFD, ctypes.int(LIBC.FD_CLOEXEC));
 +      libc.fcntl(fds[1], LIBC.F_SETFL, ctypes.int(LIBC.O_NONBLOCK));
       return fds[0];
     };
     their_pipes.set(0, pipe(false));
 diff --git a/toolkit/modules/subprocess/test/xpcshell/test_subprocess_pipe_flags.js b/toolkit/modules/subprocess/test/xpcshell/test_subprocess_pipe_flags.js
 new file mode 100644
 --- /dev/null
 +++ b/toolkit/modules/subprocess/test/xpcshell/test_subprocess_pipe_flags.js
@@ -0,0 +1,56 @@
 +/* This Source Code Form is subject to the terms of the Mozilla Public
 + * License, v. 2.0. If a copy of the MPL was not distributed with this
 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 +
 +"use strict";
 +
 +// fcntl commands for reading the flags set by the subprocess modules. The
 +// values are the same on Linux and macOS but are not exposed by
 +// ChromeUtils.getLibcConstants().
 +const F_GETFD = 1;
 +const F_GETFL = 3;
 +
 +add_task(async function test_subprocess_pipe_flags() {
 +  const { getSubprocessImplForTest } = ChromeUtils.importESModule(
 +    "resource://gre/modules/Subprocess.sys.mjs"
 +  );
 +  const { libc } = ChromeUtils.importESModule(
 +    "resource://gre/modules/subprocess/subprocess_unix.sys.mjs"
 +  );
 +  const { FD_CLOEXEC, O_NONBLOCK } = ChromeUtils.getLibcConstants();
 +
 +  const worker = getSubprocessImplForTest().Process.getWorker();
 +  equal(
 +    libc.fcntl(worker.signalFd, F_GETFD),
 +    FD_CLOEXEC,
 +    "The main-thread signal pipe has exactly FD_CLOEXEC set"
 +  );
 +
 +  const proc = await Subprocess.call({
 +    command: await Subprocess.pathSearch("cat"),
 +    stderr: "pipe",
 +  });
 +  const fds = await worker.call("getFds", [proc.id]);
 +  ok(
 +    fds.every(Number.isInteger),
 +    "The worker owns the stdin, stdout and stderr pipes"
 +  );
 +  for (const fd of fds) {
 +    equal(
 +      libc.fcntl(fd, F_GETFD),
 +      FD_CLOEXEC,
 +      "Worker pipes have exactly FD_CLOEXEC set"
 +    );
 +    equal(
 +      libc.fcntl(fd, F_GETFL) & O_NONBLOCK,
 +      O_NONBLOCK,
 +      "Worker pipes are nonblocking"
 +    );
 +  }
 +
 +  const output = proc.stdout.readString(5);
 +  await proc.stdin.write("hello");
 +  equal(await output, "hello", "The subprocess pipes transfer data");
 +  await proc.stdin.close();
 +  equal((await proc.wait()).exitCode, 0, "The subprocess exits cleanly");
 +});
 diff --git a/toolkit/modules/subprocess/test/xpcshell/xpcshell.toml b/toolkit/modules/subprocess/test/xpcshell/xpcshell.toml
 --- a/toolkit/modules/subprocess/test/xpcshell/xpcshell.toml
 +++ b/toolkit/modules/subprocess/test/xpcshell/xpcshell.toml
@@ -25,6 +25,9 @@
 ["test_subprocess_pathSearch.js"]
 ["test_subprocess_perf.js"]
 requesttimeoutfactor = 2  # Slow on Windows
 +["test_subprocess_pipe_flags.js"]
 +skip-if = ["os == 'win'"]
 +
 ["test_subprocess_polling.js"]
@@ -1,9 +1,8 @@
 diff --git a/toolkit/themes/shared/global-shared.css b/toolkit/themes/shared/global-shared.css
 --- a/toolkit/themes/shared/global-shared.css
 +++ b/toolkit/themes/shared/global-shared.css
-@@ -80,11 +80,10 @@
+@@ -80,10 +80,9 @@
     background-color: transparent;
     --panel-background: transparent;
     --panel-box-shadow: none;
     --panel-border-color: transparent;
     --panel-box-shadow-margin: 0px;
@@ -8,10 +8,14 @@
    "name": "Native MacOS popovers fix"
  },
  {
-    "type": "local",
+    "type": "phabricator",
-    // TODO: Convert into https://phabricator.services.mozilla.com/D298079
+    "id": "D323933",
-    //    once it gets accepted.
+    "name": "Issue 15123"
-    "path": "firefox/allow_backdrop_to_work_on_transparency.patch"
+  },
  {
    "type": "phabricator",
    "id": "D327914",
    "name": "Backdrop filter reads web content"
  },
  {
    "type": "local",
@@ -41,20 +45,11 @@
      "          jsonLengthHint,": "          lengthHint: jsonLengthHint,"
    }
  },
  {
    "type": "phabricator",
    "id": "D320897",
    "name": "Bug 2011236"
  },
  {
    "type": "phabricator",
    "id": "D321446",
    "name": "Issue 14710"
  },
  {
    "type": "local",
    "path": "firefox/css_corner_shape_rendering.patch"
  },
  {
    "type": "local",
    "path": "firefox/override_cert_checks_temp.patch"
@@ -1,8 +1,8 @@
 diff --git a/layout/painting/nsImageRenderer.cpp b/layout/painting/nsImageRenderer.cpp
-index 6e464b48c90174b8954aad8a79bae30a7a30cbc9..9ea9a4963ceae679f092e014ac24a0d24fb106ce 100644
+index 7ddc4f7e259272e7b905f44aff7316c1ba540c22..277a92e5d10e6a04b12373854ffe6791d562215e 100644
 --- a/layout/painting/nsImageRenderer.cpp
 +++ b/layout/painting/nsImageRenderer.cpp
-@@ -90,7 +90,7 @@ static already_AddRefed<imgIContainer> GetSymbolicIconImage(nsAtom* aName,
+@@ -95,7 +95,7 @@ static already_AddRefed<imgIContainer> GetSymbolicIconImage(nsAtom* aName,
   if (NS_WARN_IF(!XRE_IsParentProcess())) {
     return nullptr;
   }
@@ -11,7 +11,7 @@ index 6e464b48c90174b8954aad8a79bae30a7a30cbc9..9ea9a4963ceae679f092e014ac24a0d2
   auto key = std::make_tuple(aName, aScale, fg);
   auto* cache = aFrame->GetOrCreateDeletableProperty(SymbolicImageCacheProp());
   auto lookup = cache->Lookup(key);
-@@ -575,7 +575,7 @@ ImgDrawResult nsImageRenderer::Draw(nsPresContext* aPresContext,
+@@ -580,7 +580,7 @@ ImgDrawResult nsImageRenderer::Draw(nsPresContext* aPresContext,
     }
     case StyleImage::Tag::Gradient: {
       nsCSSGradientRenderer renderer = nsCSSGradientRenderer::Create(
@@ -20,7 +20,7 @@ index 6e464b48c90174b8954aad8a79bae30a7a30cbc9..9ea9a4963ceae679f092e014ac24a0d2
       renderer.Paint(*ctx, aDest, aFill, aRepeatSize, aSrc, aDirtyRect,
                      aOpacity);
-@@ -652,7 +652,7 @@ ImgDrawResult nsImageRenderer::BuildWebRenderDisplayItems(
+@@ -657,7 +657,7 @@ ImgDrawResult nsImageRenderer::BuildWebRenderDisplayItems(
   switch (mType) {
     case StyleImage::Tag::Gradient: {
       nsCSSGradientRenderer renderer = nsCSSGradientRenderer::Create(
@@ -29,16 +29,16 @@ index 6e464b48c90174b8954aad8a79bae30a7a30cbc9..9ea9a4963ceae679f092e014ac24a0d2
       renderer.BuildWebRenderDisplayItems(aBuilder, aSc, aDest, aFill,
                                           aRepeatSize, aSrc,
-@@ -678,6 +678,8 @@ ImgDrawResult nsImageRenderer::BuildWebRenderDisplayItems(
+@@ -679,6 +679,8 @@ ImgDrawResult nsImageRenderer::BuildWebRenderDisplayItems(
-           nsPresContext::AppUnitsToIntCSSPixels(aDest.height)};
+       }
-       SVGImageContext svgContext(Some(destCSSSize));
+       SVGImageContext svgContext(Some(CSSSize::FromAppUnits(aDest.Size())));
 +      SVGImageContext::MaybeStoreZenBoosts(svgContext,
 +                                           *mForFrame->PresContext());
       Maybe<ImageIntRegion> region;
       const int32_t appUnitsPerDevPixel = aPresContext->AppUnitsPerDevPixel();
-@@ -1092,7 +1094,7 @@ ImgDrawResult nsImageRenderer::DrawShapeImage(nsPresContext* aPresContext,
+@@ -1098,7 +1100,7 @@ ImgDrawResult nsImageRenderer::DrawShapeImage(nsPresContext* aPresContext,
   if (mImage->IsGradient()) {
     nsCSSGradientRenderer renderer = nsCSSGradientRenderer::Create(
@@ -1,8 +1,8 @@
 diff --git a/layout/svg/SVGGradientFrame.cpp b/layout/svg/SVGGradientFrame.cpp
-index b0d38b0fab01797328af0b1f1f48af8fb5eebe4d..953feffdc96143dc2d8f8e57f8bb4a6aeb33f0c5 100644
+index eebcced86ec1e9010b761d5df4a92684dde44009..4dc018a73a979f50ac7842e4a3f3fcf9d0071b56 100644
 --- a/layout/svg/SVGGradientFrame.cpp
 +++ b/layout/svg/SVGGradientFrame.cpp
-@@ -229,8 +229,9 @@ class MOZ_STACK_CLASS SVGColorStopInterpolator
+@@ -228,8 +228,9 @@ class MOZ_STACK_CLASS SVGColorStopInterpolator
   SVGColorStopInterpolator(
       gfxPattern* aGradient, const nsTArray<ColorStop>& aStops,
       const StyleColorInterpolationMethod& aStyleColorInterpolationMethod,
@@ -14,8 +14,8 @@ index b0d38b0fab01797328af0b1f1f48af8fb5eebe4d..953feffdc96143dc2d8f8e57f8bb4a6a
         mGradient(aGradient) {}
   void CreateStop(float aPosition, DeviceColor aColor) {
-@@ -270,7 +271,8 @@ already_AddRefed<gfxPattern> SVGGradientFrame::GetPaintServerPattern(
+@@ -269,7 +270,8 @@ already_AddRefed<gfxPattern> SVGGradientFrame::GetPaintServerPattern(
-   if (nStops == 1 || GradientVectorLengthIsZero()) {
+   if (nStops == 1 || GradientVectorLengthIsZero(gradientUnits)) {
     // The gradient paints a single colour, using the stop-color of the last
     // gradient step if there are more than one.
 -    return MakeAndAddRef<gfxPattern>(ToDeviceColor(stops.LastElement().mColor));
@@ -1,5 +1,5 @@
 diff --git a/layout/svg/SVGImageContext.h b/layout/svg/SVGImageContext.h
-index ad833c7c2ee6a4c4984efdb0d59e3576c2d1bc19..36864a34badc0cbfe44d6295798622fd6178f9e3 100644
+index 63f3c4926cfdb8b12e9e4a38016fc66f50cf3129..5ba3f2c07f521905a086ee6eea87975d5a3441ec 100644
 --- a/layout/svg/SVGImageContext.h
 +++ b/layout/svg/SVGImageContext.h
@@ -6,6 +6,7 @@
@@ -7,10 +7,10 @@ index ad833c7c2ee6a4c4984efdb0d59e3576c2d1bc19..36864a34badc0cbfe44d6295798622fd
 #include "Units.h"
 +#include "nsColor.h"
 #include "mozilla/Casting.h"
 #include "mozilla/Maybe.h"
 #include "mozilla/SVGContextPaint.h"
- #include "mozilla/SVGPreserveAspectRatio.h"
+@@ -64,6 +65,11 @@ class SVGImageContext {
@@ -63,6 +64,11 @@ class SVGImageContext {
                                      nsISVGPaintContext* aPaintContext,
                                      imgIContainer* aImgContainer);
@@ -19,10 +19,10 @@ index ad833c7c2ee6a4c4984efdb0d59e3576c2d1bc19..36864a34badc0cbfe44d6295798622fd
 +  static void MaybeStoreZenBoosts(SVGImageContext& aContext,
 +                                  const nsPresContext& aPresContext);
 +
-   const Maybe<CSSIntSize>& GetViewportSize() const { return mViewportSize; }
+   const Maybe<CSSSize>& GetViewportSize() const { return mViewportSize; }
-   void SetViewportSize(const Maybe<CSSIntSize>& aSize) {
+   void SetViewportSize(const Maybe<CSSSize>& aSize) { mViewportSize = aSize; }
-@@ -75,6 +81,21 @@ class SVGImageContext {
+@@ -74,6 +80,21 @@ class SVGImageContext {
     mColorScheme = aScheme;
   }
@@ -44,7 +44,7 @@ index ad833c7c2ee6a4c4984efdb0d59e3576c2d1bc19..36864a34badc0cbfe44d6295798622fd
   const Maybe<SVGPreserveAspectRatio>& GetPreserveAspectRatio() const {
     return mPreserveAspectRatio;
   }
-@@ -110,7 +131,11 @@ class SVGImageContext {
+@@ -109,7 +130,11 @@ class SVGImageContext {
     return contextPaintIsEqual && mViewportSize == aOther.mViewportSize &&
            mPreserveAspectRatio == aOther.mPreserveAspectRatio &&
            mColorScheme == aOther.mColorScheme &&
@@ -56,8 +56,8 @@ index ad833c7c2ee6a4c4984efdb0d59e3576c2d1bc19..36864a34badc0cbfe44d6295798622fd
 +           mZenBoostsInverted == aOther.mZenBoostsInverted;
   }
-   bool operator!=(const SVGImageContext&) const = default;
+   PLDHashNumber Hash() const {
-@@ -123,7 +148,8 @@ class SVGImageContext {
+@@ -120,7 +145,8 @@ class SVGImageContext {
     return AddToHash(hash, mViewportSize.map(HashSize).valueOr(0),
                      mPreserveAspectRatio.map(HashPAR).valueOr(0),
                      mColorScheme.map(HashColorScheme).valueOr(0),
@@ -67,7 +67,7 @@ index ad833c7c2ee6a4c4984efdb0d59e3576c2d1bc19..36864a34badc0cbfe44d6295798622fd
   }
  private:
-@@ -156,6 +182,9 @@ class SVGImageContext {
+@@ -154,6 +180,9 @@ class SVGImageContext {
   Maybe<SVGPreserveAspectRatio> mPreserveAspectRatio;
   Maybe<ColorScheme> mColorScheme;
   StyleLinkParameters mLinkParameters;
@@ -1,29 +0,0 @@
 diff --git a/toolkit/content/widgets/panel-list/panel-list.mjs b/toolkit/content/widgets/panel-list/panel-list.mjs
 index 68ad2fafc8b31dfff541cf8381d9b9533e376d1c..fa62fec6bfb33338091fc06d3736fb76fd5c47c4 100644
 --- a/toolkit/content/widgets/panel-list/panel-list.mjs
 +++ b/toolkit/content/widgets/panel-list/panel-list.mjs
@@ -223,7 +223,12 @@ export class PanelList extends HTMLElement {
     this.setAttribute("showing", "true");
     // Tell the host element to hide any overflow in case the panel extends off
     // the page before the alignment is set.
 -    hostElement.style.overflow = "hidden";
 +    const hostHidesOverflow = !getComputedStyle(hostElement)
 +      .overflow.split(" ")
 +      .includes("visible");
 +    if (!hostHidesOverflow) {
 +      hostElement.style.overflow = "hidden";
 +    }
     // Wait for a layout flush, then find the bounds.
     let {
@@ -344,7 +349,9 @@ export class PanelList extends HTMLElement {
       // Set the alignments and show the panel.
       this.setAttribute("align", align);
       this.setAttribute("valign", valign);
 -      hostElement.style.overflow = "";
 +      if (!hostHidesOverflow) {
 +        hostElement.style.overflow = "";
 +      }
       // Decide positioning based on where this panel will be rendered
       const offsetParentIsBody =
         this.supportsPopover() ||
@@ -1,5 +1,5 @@
 diff --git a/toolkit/themes/shared/design-system/dist/tokens-shared.css b/toolkit/themes/shared/design-system/dist/tokens-shared.css
-index 63c641f560d4c0ce06b40a652ca99d1c48cd6941..39c81e773a442870763396e68fb57bd336e3625a 100644
+index b0f8fa146de335c53e73d46853f45dda9b15cc73..1b7592c0e9ca12fd9d1f8a555633fd39c2efb537 100644
 --- a/toolkit/themes/shared/design-system/dist/tokens-shared.css
 +++ b/toolkit/themes/shared/design-system/dist/tokens-shared.css
@@ -7,6 +7,8 @@
@@ -8,9 +8,9 @@ index 63c641f560d4c0ce06b40a652ca99d1c48cd6941..39c81e773a442870763396e68fb57bd3
 +@import url("chrome://browser/content/zen-styles/zen-theme.css");
 +
- @layer tokens-foundation {
+ :root,
-   :root,
+ :host(.anonymous-content-host) {
-   :host(.anonymous-content-host) {
+   @layer tokens-foundation {
@@ -28,10 +30,10 @@
     --border-color-selected: var(--color-accent-primary);
     --border-color-transparent: transparent;
@@ -1,16 +1,17 @@
 diff --git a/widget/cocoa/nsCocoaWindow.mm b/widget/cocoa/nsCocoaWindow.mm
-index 2efd02e4a92433fd29bbfdb707aa81cfec45031e..3b763c3927f07e529c826f8e4f62bc80a324b247 100644
+index 887e4c052d5dd2b73d4c2059463529fb4b09dcab..36da18e19018b1b216576c299f938e75093546d3 100644
 --- a/widget/cocoa/nsCocoaWindow.mm
 +++ b/widget/cocoa/nsCocoaWindow.mm
-@@ -86,6 +86,7 @@
+@@ -86,6 +86,8 @@
 #include "mozilla/StaticPrefs_gfx.h"
 #include "mozilla/StaticPrefs_ui.h"
 #include "mozilla/StaticPrefs_widget.h"
 +#include "mozilla/StaticPrefs_zen.h"
 +#include "mozilla/nsZenDragAndDrop.h"
 #include "mozilla/WritingModes.h"
 #include "mozilla/dom/Document.h"
 #include "mozilla/layers/CompositorBridgeChild.h"
-@@ -1332,6 +1333,110 @@ - (NSRect)_opaqueRectForWindowMoveWhenInTitlebar {
+@@ -1332,6 +1334,110 @@ - (NSRect)_opaqueRectForWindowMoveWhenInTitlebar {
 }
 @end
@@ -121,7 +122,28 @@ index 2efd02e4a92433fd29bbfdb707aa81cfec45031e..3b763c3927f07e529c826f8e4f62bc80
 void nsCocoaWindow::UpdateWindowDraggingRegion(
     const LayoutDeviceIntRegion& aRegion) {
   // mChildView returns YES from mouseDownCanMoveWindow, so we need to put
-@@ -4919,6 +5024,10 @@ - (BOOL)wantsBestResolutionOpenGLSurface {
+@@ -3858,7 +3964,9 @@ - (NSDragOperation)draggingEntered:(id<NSDraggingInfo>)sender {
 // NSDraggingDestination
 - (NSDragOperation)draggingUpdated:(id<NSDraggingInfo>)sender {
   MOZ_LOG(sCocoaLog, LogLevel::Info, ("ChildView draggingUpdated: entered\n"));
 -  return [self doDragAction:eDragOver sender:sender];
 +  NSDragOperation operation = [self doDragAction:eDragOver sender:sender];
 +  zen::PrepareDropLanding(sender);
 +  return operation;
 }
 // NSDraggingDestination
@@ -3874,6 +3982,9 @@ - (void)draggingExited:(id<NSDraggingInfo>)sender {
 - (BOOL)performDragOperation:(id<NSDraggingInfo>)sender {
   nsAutoRetainCocoaObject kungFuDeathGrip(self);
   BOOL handled = [self doDragAction:eDrop sender:sender] != NSDragOperationNone;
 +  if (handled) {
 +    zen::LandDrop(sender);
 +  }
   NS_IF_RELEASE(mDragService);
   return handled;
 }
@@ -4919,6 +5030,10 @@ - (BOOL)wantsBestResolutionOpenGLSurface {
 nsCocoaWindow::~nsCocoaWindow() {
   NS_OBJC_BEGIN_TRY_IGNORE_BLOCK;
@@ -1,5 +1,5 @@
 diff --git a/widget/cocoa/nsDragService.mm b/widget/cocoa/nsDragService.mm
-index 340a9ad81c5cb23bb7e5f927d11d5cffdde7ce70..32fc707ccfa56fa8c307860868d092c4a9050419 100644
+index 340a9ad81c5cb23bb7e5f927d11d5cffdde7ce70..ba597ba4373ba3ace7455ce0859f2339349ffc06 100644
 --- a/widget/cocoa/nsDragService.mm
 +++ b/widget/cocoa/nsDragService.mm
@@ -10,6 +10,7 @@
@@ -45,3 +45,112 @@ index 340a9ad81c5cb23bb7e5f927d11d5cffdde7ce70..32fc707ccfa56fa8c307860868d092c4
 #endif
       src += 4;
       dest += 4;
@@ -249,12 +254,44 @@
       [[[NSDraggingItem alloc] initWithPasteboardWriter:pbItem] autorelease];
   [dragItem setDraggingFrame:localDragRect contents:image];
 +  NSMutableArray* dragItems = [NSMutableArray arrayWithObject:dragItem];
 +  auto zenDragAndDrop = zen::nsZenDragAndDrop::GetZenDragAndDropInstance();
 +  const nsTArray<nsCOMPtr<nsINode>> noExtraImages;
 +  @try {
 +    for (const auto& extraImageNode :
 +         zenDragAndDrop ? zenDragAndDrop->DragImages() : noExtraImages) {
 +      nsCOMPtr<nsINode> mainImage = std::move(mImage);
 +      mImage = extraImageNode;
 +      NSPoint extraPoint;
 +      NSImage* extraImage = ConstructDragImage(mSourceNode, aRegion, &extraPoint);
 +      mImage = std::move(mainImage);
 +      if (!extraImage) {
 +        continue;
 +      }
 +      NSRect extraRect = extraImage.alignmentRect;
 +      extraRect.origin.x = extraPoint.x;
 +      extraRect.origin.y = extraPoint.y - extraRect.size.height;
 +      NSPasteboardItem* extraPbItem = [[NSPasteboardItem new] autorelease];
 +      [extraPbItem setData:[NSData data]
 +                   forType:[UTIHelper stringFromPboardType:kMozWildcardPboardType]];
 +      NSDraggingItem* extraItem = [[[NSDraggingItem alloc]
 +          initWithPasteboardWriter:extraPbItem] autorelease];
 +      [extraItem setDraggingFrame:extraRect contents:extraImage];
 +      [dragItems addObject:extraItem];
 +    }
 +  } @catch (NSException* e) {
 +    dragItems = [NSMutableArray arrayWithObject:dragItem];
 +  }
 +
   OpenDragPopup();
   mNSDraggingSession = [mNativeDragView
 -      beginDraggingSessionWithItems:[NSArray arrayWithObject:dragItem]
 +      beginDraggingSessionWithItems:dragItems
                               event:mNativeDragEvent
                              source:mNativeDragView];
 +  if (dragItems.count > 1) {
 +    mNSDraggingSession.draggingFormation = NSDraggingFormationStack;
 +  }
   mNSDraggingSession.animatesToStartingPositionsOnCancelOrFail =
       !mDataTransfer || mDataTransfer->MozShowFailAnimation();
@@ -455,29 +492,44 @@
     }
     if (pc) {
 +      nsPoint pt = LayoutDevicePixel::ToAppUnits(
 +          devPoint, pc->DeviceContext()->AppUnitsPerDevPixel());
 +      CSSIntPoint screenPoint =
 +          CSSIntPoint(nsPresContext::AppUnitsToIntCSSPixels(pt.x),
 +                      nsPresContext::AppUnitsToIntCSSPixels(pt.y));
 +
 +      NSMutableArray* images = [NSMutableArray array];
 +      NSMutableArray* rects = [NSMutableArray array];
 +      auto render = [&]() {
 +        LayoutDeviceIntRect newRect;
 +        NSImage* image =
 +            ConstructDragImage(mSourceNode, Nothing(), screenPoint, &newRect);
 +        [images addObject:image ? (id)image : (id)[NSNull null]];
 +        [rects addObject:[NSValue valueWithRect:
 +                                      image ? nsCocoaUtils::GeckoRectToCocoaRectDevPix(
 +                                                  newRect, scaleFactor)
 +                                            : NSZeroRect]];
 +      };
 +      render();
 +      if (auto zenDragAndDrop = zen::nsZenDragAndDrop::GetZenDragAndDropInstance()) {
 +        for (const auto& extraImageNode : zenDragAndDrop->DragImages()) {
 +          nsCOMPtr<nsINode> mainImage = std::move(mImage);
 +          mImage = extraImageNode;
 +          render();
 +          mImage = std::move(mainImage);
 +        }
 +      }
 +
       void (^changeImageBlock)(NSDraggingItem*, NSInteger, BOOL*) = ^(
           NSDraggingItem* draggingItem, NSInteger idx, BOOL* stop) {
 -        // We never add more than one item right now, but check just in case.
 -        if (idx > 0) {
 +        if ((NSUInteger)idx >= images.count || images[idx] == [NSNull null]) {
           return;
         }
 -
 -        nsPoint pt = LayoutDevicePixel::ToAppUnits(
 -            devPoint, pc->DeviceContext()->AppUnitsPerDevPixel());
 -        CSSIntPoint screenPoint =
 -            CSSIntPoint(nsPresContext::AppUnitsToIntCSSPixels(pt.x),
 -                        nsPresContext::AppUnitsToIntCSSPixels(pt.y));
 -
 -        // Create a new image; if one isn't returned don't change the current
 -        // one.
 -        LayoutDeviceIntRect newRect;
 -        NSImage* image =
 -            ConstructDragImage(mSourceNode, Nothing(), screenPoint, &newRect);
 -        if (image) {
 -          NSRect draggingRect =
 -              nsCocoaUtils::GeckoRectToCocoaRectDevPix(newRect, scaleFactor);
 -          [draggingItem setDraggingFrame:draggingRect contents:image];
 +        NSRect frame = [rects[idx] rectValue];
 +        if (idx > 0) {
 +          frame.origin = draggingItem.draggingFrame.origin;
         }
 +        [draggingItem setDraggingFrame:frame contents:images[idx]];
       };
       [mNSDraggingSession
@@ -69,7 +69,9 @@ export class nsZenBoostEditor {
   * @returns {ZenBoostsParent} Boost JSActor parent
   */
  get zenBoostsParent() {
-    const linkedBrowser = this.openerWindow.gBrowser.selectedTab.linkedBrowser;
+    const linkedBrowser =
      this.editorWindow.browser ??
      this.openerWindow.gBrowser.selectedTab.linkedBrowser;
    const actor =
      linkedBrowser.browsingContext.currentWindowGlobal.getActor("ZenBoosts");
    return actor;
@@ -1521,7 +1523,7 @@ ${cssSelector} {
  shuffleBoost() {
    const availFonts = this.fetchFontList();
    const commonFonts = this.commonFonts;
-    let font = commonFonts[Math.round(Math.random() * commonFonts.length)];
+    let font = commonFonts[Math.floor(Math.random() * commonFonts.length)];
    if (availFonts.includes(font)) {
      this.currentBoostData.fontFamily = font;
    }
@@ -606,9 +606,12 @@ class nsZenBoostsManager {
   * @param {Window} parentWindow - The parent browser window
   * @param {Boost} boost - The boost which will be edited
   * @param {nsIURI} domainUri - The boost which will be edited
   * @param {object} [options]
   * @param {Element} [options.browser] - Browser showing the site when it is
   *   not the selected tab, e.g. a detached glance
   * @returns {Window|null} The instanced editor window
   */
-  openBoostWindow(parentWindow, boost, domainUri) {
+  openBoostWindow(parentWindow, boost, domainUri, { browser = null } = {}) {
    if (!this.canBoostSite(domainUri)) {
      console.error(
        "[ZenBoostsManager] Cannot open editor for boost with invalid domain."
@@ -648,26 +651,51 @@ class nsZenBoostsManager {
      null
    );
    // Close the editor if the tab is switched
    parentWindow.gBrowser.tabContainer.addEventListener(
      "TabSelect",
      editor.close.bind(editor),
      {
        once: true,
      }
    );
    const progressListener = {
      QueryInterface: ChromeUtils.generateQI([
        "nsIWebProgressListener",
        "nsISupportsWeakReference",
      ]),
      onLocationChange: webProgress => {
        if (webProgress.isTopLevel) {
          editor.close();
          parentWindow.gBrowser.removeTabsProgressListener(progressListener);
        }
      },
    };
    const onTabSelect = editor.close.bind(editor);
    if (browser) {
      browser.addProgressListener(progressListener);
      editor.addEventListener(
        "unload",
        () => {
          browser.removeProgressListener(progressListener);
          editor.browser = null;
        },
        { once: true }
      );
    } else {
      // Close the editor if the tab is switched or navigates.
      parentWindow.gBrowser.tabContainer.addEventListener(
        "TabSelect",
        onTabSelect,
        { once: true }
      );
      parentWindow.gBrowser.addProgressListener(progressListener);
      editor.addEventListener(
        "unload",
        () => {
          parentWindow.gBrowser.tabContainer.removeEventListener(
            "TabSelect",
            onTabSelect
          );
          parentWindow.gBrowser.removeProgressListener(progressListener);
          editor.browser = null;
        },
        { once: true }
      );
    }
-    parentWindow.gBrowser.addProgressListener(progressListener);
+    editor.browser = browser;
    // Give the domain
    editor.domain = domain;
    editor.openerWindow = parentWindow;
@@ -70,8 +70,10 @@ export class ZenBoostsChild extends JSWindowActorChild {
  static PREVENTABLE_SET = new Set(ZenBoostsChild.PREVENTABLE_EVENTS);
-  actorCreated() {
+  handleEvent(event) {
-    this.#applyBoostForPageIfAvailable();
+    if (event.type === "DOMDocElementInserted") {
      this.#applyBoostForPageIfAvailable();
    }
  }
  didDestroy() {
@@ -330,6 +332,22 @@ export class ZenBoostsChild extends JSWindowActorChild {
    return this.sendQuery("ZenBoost:GetBoostForDomain", domain);
  }
  /**
   * Sets a synced BrowsingContext field only when its value changes. Every
   * setter commits a transaction that is broadcast to the whole browsing
   * context group, even when the value is unchanged, so this avoids three
   * such broadcasts on every page load that has no boost.
   *
   * @param {BrowsingContext} browsingContext
   * @param {string} field - The synced field name.
   * @param {number | boolean} value
   */
  #setSyncedField(browsingContext, field, value) {
    if (browsingContext[field] !== value) {
      browsingContext[field] = value;
    }
  }
  /**
   * Applies the boost settings for the current page if available.
   *
@@ -360,7 +378,11 @@ export class ZenBoostsChild extends JSWindowActorChild {
        sizeOverride: boostData.sizeOverride,
      });
-      browsingContext.isZenBoostsInverted = boostData.smartInvert;
+      this.#setSyncedField(
        browsingContext,
        "isZenBoostsInverted",
        !!boostData.smartInvert
      );
      if (boostData.enableColorBoost) {
        let primaryColor;
        if (boostData.autoTheme) {
@@ -396,18 +418,21 @@ export class ZenBoostsChild extends JSWindowActorChild {
            boostData
          );
        }
-        browsingContext.zenBoostsData = primaryColor;
+        this.#setSyncedField(browsingContext, "zenBoostsData", primaryColor);
        // The complementary accent is derived in the backend by rotating the
        // primary accent's hue by this delta (in degrees).
-        browsingContext.zenBoostsComplementaryRotation =
+        this.#setSyncedField(
-          boostData.secondaryDotAngleDegDelta ?? 0;
+          browsingContext,
          "zenBoostsComplementaryRotation",
          boostData.secondaryDotAngleDegDelta ?? 0
        );
        return;
      }
    } else {
-      browsingContext.isZenBoostsInverted = false;
+      this.#setSyncedField(browsingContext, "isZenBoostsInverted", false);
    }
-    browsingContext.zenBoostsData = 0;
+    this.#setSyncedField(browsingContext, "zenBoostsData", 0);
-    browsingContext.zenBoostsComplementaryRotation = 0;
+    this.#setSyncedField(browsingContext, "zenBoostsComplementaryRotation", 0);
  }
  /**
@@ -28,6 +28,7 @@
    "chrome://browser/content/zen-components/ZenEmojiPicker.mjs",
    "chrome://browser/content/zen-components/ZenLiveFoldersUI.mjs",
    "chrome://browser/content/zen-components/ZenDownloadAnimation.mjs",
    "resource:///modules/zen/share/ZenShareManager.mjs",
  ];
  for (let script of scripts) {
@@ -23,7 +23,7 @@
        content/browser/zen-styles/zen-browser-ui.css                           (../../zen/common/styles/zen-browser-ui.css)
        content/browser/zen-styles/zen-animations.css                           (../../zen/common/styles/zen-animations.css)
        content/browser/zen-styles/zen-panel-ui.css                             (../../zen/common/styles/zen-panel-ui.css)
-        content/browser/zen-styles/zen-single-components.css                    (../../zen/common/styles/zen-single-components.css)
+*       content/browser/zen-styles/zen-single-components.css                    (../../zen/common/styles/zen-single-components.css)
        content/browser/zen-styles/zen-sidebar.css                              (../../zen/common/styles/zen-sidebar.css)
 *       content/browser/zen-styles/zen-toolbar.css                              (../../zen/common/styles/zen-toolbar.css)
        content/browser/zen-styles/zen-browser-container.css                    (../../zen/common/styles/zen-browser-container.css)
@@ -31,6 +31,7 @@
        content/browser/zen-styles/zen-popup.css                                (../../zen/common/styles/zen-popup.css)
        content/browser/zen-styles/zen-branding.css                             (../../zen/common/styles/zen-branding.css)
        content/browser/zen-styles/zen-sidebar-notification.css                 (../../zen/common/styles/zen-sidebar-notification.css)
 *       content/browser/zen-styles/zen-backdrop-filters.svg                     (../../zen/common/styles/zen-backdrop-filters.svg)
        content/browser/zen-styles/zen-panels/bookmarks.css                     (../../zen/common/styles/zen-panels/bookmarks.css)
        content/browser/zen-styles/zen-panels/print.css                         (../../zen/common/styles/zen-panels/print.css)
@@ -146,6 +146,20 @@ window.gZenUIManager = {
    });
  },
  /**
   * Shakes an element from side to side to catch the user's eye.
   *
   * @param {Element} element
   * @param {number} delay Milliseconds to wait before shaking.
   */
  shakeElement(element, delay = 0) {
    return this.elementAnimate(
      element,
      { x: [0, -12, 8, -4, 2, 0] },
      { duration: 600, delay, easing: "ease-out" }
    );
  },
  _addNewCustomizableButtonsIfNeeded() {
    const kPref = "zen.ui.migration.compact-mode-button-added";
    let navbarPlacements = CustomizableUI.getWidgetIdsInArea(
@@ -257,7 +271,7 @@ window.gZenUIManager = {
    };
  },
-  updateTabsToolbar() {
+  updateTabsToolbar(fromResizeEvent = false) {
    const kUrlbarHeight = 333;
    gURLBar.style.setProperty(
      "--zen-urlbar-top",
@@ -270,8 +284,8 @@ window.gZenUIManager = {
    gZenVerticalTabsManager.actualWindowButtons.removeAttribute(
      "zen-has-hover"
    );
-    gZenVerticalTabsManager.recalculateURLBarHeight(true);
+    gZenVerticalTabsManager.recalculateURLBarHeight(!fromResizeEvent);
-    if (!this._preventToolbarRebuild) {
+    if (!this._preventToolbarRebuild && !fromResizeEvent) {
      setTimeout(() => {
        gZenWorkspaces.updateTabsContainers();
      }, 0);
@@ -990,14 +1004,7 @@ window.gZenVerticalTabsManager = {
    });
    ChromeUtils.defineLazyGetter(this, "hidesTabsToolbar", () => {
-      return (
+      return document.documentElement.hasAttribute("popup-window");
        document.documentElement
          .getAttribute("chromehidden")
          ?.includes("toolbar") ||
        document.documentElement
          .getAttribute("chromehidden")
          ?.includes("menubar")
      );
    });
    XPCOMUtils.defineLazyPreferenceGetter(
@@ -1278,8 +1285,16 @@ window.gZenVerticalTabsManager = {
    if (gZenWorkspaces._processingResize) {
      return;
    }
    this._pendingUrlbarFormatUpdate ||= updateFormat;
    if (this._urlbarHeightRecalcScheduled) {
      return;
    }
    this._urlbarHeightRecalcScheduled = true;
    requestAnimationFrame(() => {
      requestAnimationFrame(() => {
        delete this._urlbarHeightRecalcScheduled;
        const shouldUpdateFormat = this._pendingUrlbarFormatUpdate;
        delete this._pendingUrlbarFormatUpdate;
        gURLBar.removeAttribute("--urlbar-height");
        let height;
        if (!this._hasSetSingleToolbar) {
@@ -1290,7 +1305,7 @@ window.gZenVerticalTabsManager = {
        if (typeof height !== "undefined") {
          gURLBar.style.setProperty("--urlbar-height", `${height}px`);
        }
-        if (updateFormat) {
+        if (shouldUpdateFormat) {
          gURLBar.zenFormatURLValue();
        }
      });
@@ -1403,18 +1418,37 @@ window.gZenVerticalTabsManager = {
      if (isSingleToolbar) {
        this._navbarParent = navBar.parentElement;
-        let elements = document.querySelectorAll(
+        let elements = Array.from(
-          '#nav-bar-customization-target > :is([cui-areatype="toolbar"], .chromeclass-toolbar-additional):not(#urlbar-container):not(toolbarspring)'
+          document.querySelectorAll(
            '#nav-bar-customization-target > :is([cui-areatype="toolbar"], .chromeclass-toolbar-additional):not(#urlbar-container):not(toolbarspring)'
          )
        );
-        elements = Array.from(elements).reverse();
+        let normalButtons = [];
        let extensionButtons = [];
        for (const element of elements) {
          if (
            element.hasAttribute("data-extensionid") &&
            Services.prefs.getBoolPref("zen.view.overflow-webext-toolbar", true)
          ) {
            extensionButtons.push(element);
          } else {
            normalButtons.push(element);
          }
        }
        // Add separator if it doesn't exist
        if (!this._hasSetSingleToolbar) {
          buttonsTarget.append(this._topButtonsSeparatorElement);
        }
        this._hasSetSingleToolbar = true;
-        for (const button of elements) {
+        for (const button of normalButtons.reverse()) {
          this.appendCustomizableItem(this._topButtonsSeparatorElement, button);
        }
        for (const extension of extensionButtons) {
          this.appendCustomizableItem(
            this._topButtonsSeparatorElement,
            extension
          );
        }
        buttonsTarget.prepend(
          document.getElementById("unified-extensions-button")
        );
@@ -1575,13 +1609,7 @@ window.gZenVerticalTabsManager = {
  },
  rebuildURLBarMenus() {
-    if (document.getElementById("paste-and-go")) {
+    gURLBar.updatePlaceholder();
      return;
    }
    gURLBar._initCopyCutController();
    gURLBar._initPasteAndGo();
    gURLBar._initStripOnShare();
    gURLBar._updatePlaceholderFromDefaultEngine();
  },
  rebuildAreas() {
@@ -3,5 +3,5 @@
 % file, You can obtain one at http://mozilla.org/MPL/2.0/.
 color-scheme: dark;
 --zen-backdrop-underlay: url("chrome://browser/content/zen-styles/zen-backdrop-filters.svg#underlay-dark");
 --zen-urlbar-outline-offset: -2px;
 --zen-urlbar-filter: blur(40px) saturate(110%) brightness(25%) contrast(100%);
@@ -3,5 +3,5 @@
 % file, You can obtain one at http://mozilla.org/MPL/2.0/.
 color-scheme: light;
 --zen-backdrop-underlay: url("chrome://browser/content/zen-styles/zen-backdrop-filters.svg#underlay-light");
 --zen-urlbar-outline-offset: 0px;
 --zen-urlbar-filter: blur(40px) saturate(110%) brightness(75%) contrast(100%);
@@ -0,0 +1,37 @@
 /*
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */
 /* Upstream elements that take their radius from --border-radius-circle (9999px).
   They are meant to read as circles or pills, so a superellipse only makes them
   look lumpy. */
 .tab-icon-overlay:not([crashed]):is([soundplaying], [muted], [activemedia-blocked]),
 .tab-note-icon-overlay,
 .tab-group-overflow-count,
 .tab-group-editor-swatch,
 .tab-preview-container-indicator,
 .tab-preview-thumbnail-container > canvas,
 #tabbrowser-tabs[orient='vertical']:not([expanded]) .tab-close-button,
 .all-tabs-item > toolbarbutton.all-tabs-container-indicator::before,
 .urlbarView-button,
 .downloadButton,
 .titlebar-button,
 .titlebar-button .toolbarbutton-icon,
 #downloads-indicator-progress-inner,
 #smartwindow-ask-button-inner,
 #PanelUI-fxa-menu-manage-account-button,
 .fxa-menu-manage-account-avatar,
 [fxastatus='signedin'] #fxa-avatar-image,
 #profile-icon-image,
 .appMenu-update-banner-pulse-ring,
 .urlbarView-favicon,
 :is(#appMenu-zoomReduce-button2, #appMenu-zoomEnlarge-button2) > .toolbarbutton-icon,
 .color-swatches .userContext-icon,
 .reusable-relay-masks > button,
 .radio-check,
 #zen-loading-progress-bar,
 #statuspanel-label {
  corner-shape: round;
 }
@@ -4,6 +4,38 @@
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */
@keyframes library-badge-download {
  0% {
    transform: translateY(0);
  }
  20% {
    transform: translateY(12px);
  }
  100% {
    transform: translateY(0);
  }
 }
@keyframes zen-library-sprite-hover {
  from {
    background-position-x: 0%;
  }
  to {
    background-position-x: 100%;
  }
 }
@keyframes zen-library-sprite-unhover {
  from {
    background-position-x: 100%;
  }
  to {
    background-position-x: 0%;
  }
 }
@keyframes zen-back-and-forth-text {
  0%,
  10% {
@@ -0,0 +1,20 @@
 #filter dumbComments emptyLines substitution
 # This Source Code Form is subject to the terms of the Mozilla Public
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 <svg xmlns="http://www.w3.org/2000/svg">
  <filter id="underlay-dark" x="0" y="0" width="100%" height="100%" color-interpolation-filters="sRGB">
    <feFlood flood-color="black" />
    <feMerge>
      <feMergeNode />
      <feMergeNode in="SourceGraphic" />
    </feMerge>
  </filter>
  <filter id="underlay-light" x="0" y="0" width="100%" height="100%" color-interpolation-filters="sRGB">
    <feFlood flood-color="white" />
    <feMerge>
      <feMergeNode />
      <feMergeNode in="SourceGraphic" />
    </feMerge>
  </filter>
 </svg>
@@ -3,13 +3,15 @@
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */
-:root:not([inDOMFullscreen="true"]):not([chromehidden~="location"]):not([chromehidden~="toolbar"]) {
+:root:not([inDOMFullscreen="true"]):not([popup-window]) {
  & #tabbrowser-tabbox #tabbrowser-tabpanels .browserSidebarContainer {
    --zen-transparent-browser-background: light-dark(rgba(255, 255, 255, 0.6), rgba(255, 255, 255, 0.1));
    overflow: clip;
    :root:not([zen-no-padding="true"]) &:not(.zen-glance-overlay) {
-      border-radius: var(--zen-native-inner-radius);
+      /* stylelint-disable-next-line property-no-unknown */
-      box-shadow: var(--zen-big-shadow);
+      corner-shape: round;
      border-radius: calc(var(--zen-native-inner-radius) / var(--zen-squircle-value));
    }
    & browser[type="content"] {
@@ -18,7 +20,7 @@
      }
      &[transparent="true"] {
-        background: light-dark(rgba(255, 255, 255, 0.6), rgba(255, 255, 255, 0.1));
+        background: var(--zen-transparent-browser-background);
      }
    }
@@ -28,18 +30,6 @@
        color-scheme: env(-moz-content-preferred-color-scheme);
      }
    }
    /* stylelint-disable-next-line media-query-no-invalid */
    @media -moz-pref("zen.theme.acrylic-elements") {
      & browser[type="content"] {
        /* For the rendering engine to apply layering optimizations. This
         * is a hacky solution, but it works for now. Note that this makes
         * zen REALLY slow, so lets not enable it by default until we have
         * a better solution. */
        translate: 0;
        backface-visibility: hidden;
      }
    }
  }
  /* stylelint-disable-next-line media-query-no-invalid */
@@ -20,7 +20,7 @@ body,
  position: inherit;
 }
-:root:is([inDOMFullscreen="true"], [chromehidden~="location"], [chromehidden~="toolbar"]) {
+:root:is([inDOMFullscreen="true"], [popup-window]) {
  #navigator-toolbox,
  #zen-sidebar-splitter {
    visibility: collapse;
@@ -61,7 +61,7 @@ body,
    background: var(--zen-main-browser-background);
    opacity: var(--zen-background-opacity);
    transition: 0s;
-    background-blend-mode: screen;
+    background-blend-mode: lighten;
  }
  &:is(.zen-toolbar-background) {
@@ -74,7 +74,7 @@ body,
    background: var(--zen-main-browser-background-old);
    opacity: calc(1 - var(--zen-background-opacity));
    transition: 0s;
-    background-blend-mode: screen;
+    background-blend-mode: lighten;
  }
  &:is(.zen-toolbar-background) {
@@ -100,14 +100,14 @@ body,
    display: flex;
    opacity: var(--zen-grainy-background-opacity, 0);
-    :root:not([swipe-gesture="true"]) & {
+    &:not([swipe-gesture="true"]) {
      /* note: Keep in sync with kGlobalAnimationDuration */
      transition: opacity 0.2s ease-in-out;
    }
  }
 }
-:root[swipe-gesture] #tabbrowser-arrowscrollbox {
+#tabbrowser-arrowscrollbox[swipe-gesture] {
  /* See gh-13703 for rationale. */
  pointer-events: none;
 }
@@ -152,7 +152,7 @@ body,
  }
  & > * {
-    z-index: 1;
+    z-index: var(--zen-main-app-child-z-index, 1);
  }
  /* stylelint-disable-next-line media-query-no-invalid */
@@ -170,7 +170,7 @@ body,
  min-width: 1px;
 }
-:root:not([inDOMFullscreen="true"]):not([chromehidden~="location"]):not([chromehidden~="toolbar"]) {
+:root:not([inDOMFullscreen="true"]):not([popup-window]) {
  & #zen-tabbox-wrapper {
    margin: var(--zen-element-separation);
    margin-top: 0;
@@ -78,3 +78,52 @@ dialog::part(dialog-button) {
    scale: 0.98;
  }
 }
 :root {
  --zen-accent-button-color: light-dark(
    oklch(from var(--zen-primary-color) clamp(0.35, l, 0.6) c h),
    oklch(from var(--zen-primary-color) clamp(0.7, l, 0.85) c h)
  );
  --zen-accent-button-background: light-dark(
    oklch(from var(--zen-primary-color) clamp(0.35, l, 0.6) c h),
    oklch(from var(--zen-primary-color) clamp(0.55, l, 0.7) c h)
  );
 }
 .zen-big-accent-button {
  appearance: none;
  border: none;
  border-radius: 12px;
  padding: 1.2rem 1rem;
  background: transparent;
  color: var(--zen-accent-button-color);
  font: inherit;
  font-size: 1.2rem;
  font-weight: 600;
  cursor: pointer;
  will-change: transform;
  transition: scale 0.15s ease-out;
  &:hover {
    scale: 1.03;
    filter: brightness(1.1);
  }
  &:active:hover {
    scale: 1;
    color: color-mix(in srgb, var(--zen-accent-button-color) 80%, transparent);
  }
  &.primary {
    background: var(--zen-accent-button-background);
    color: white;
    &:hover {
      filter: brightness(1.1);
    }
    &:active:hover {
      color: rgba(255, 255, 255, 0.8);
    }
  }
 }
@@ -0,0 +1,94 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 .zen-library-media-preview {
  position: absolute;
  inset: 0;
  --zen-main-app-child-z-index: 3;
  display: flex;
  align-items: center;
  justify-content: center;
 }
 .zen-library-media-preview-backdrop {
  position: absolute;
  inset: 0;
  background: light-dark(rgba(255, 255, 255, 0.55), rgba(0, 0, 0, 0.45));
 }
 .zen-library-media-preview-panel {
  position: relative;
  display: flex;
  flex-direction: column;
  width: min(78vw, 1100px);
  border-radius: 18px;
  overflow: hidden;
  background: light-dark(rgb(245, 245, 247), rgb(28, 30, 32));
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.45);
 }
 .zen-library-media-preview-header {
  --zen-toolbar-button-size: 15px;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 12px;
  flex: none;
  color: light-dark(rgb(28, 30, 32), rgb(233, 234, 237));
 }
 .zen-library-media-preview-name {
  margin-inline-start: 6px;
  font-size: 13px;
  font-weight: 600;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
 }
 .zen-library-media-preview-date {
  font-size: 13px;
  opacity: 0.6;
  margin-inline-end: auto;
  white-space: nowrap;
 }
 .zen-library-media-preview .toolbarbutton-1 > .toolbarbutton-icon {
  box-sizing: border-box;
  -moz-context-properties: fill;
  fill: var(--toolbarbutton-icon-fill);
 }
 .zen-library-media-preview-open {
  & > .toolbarbutton-text {
    display: block;
    margin: 0;
    padding: 5px 10px;
    border-radius: var(--toolbarbutton-border-radius);
    background: color-mix(in srgb, currentColor 12%, transparent);
    font-weight: 600;
  }
  &:hover > .toolbarbutton-text {
    background: color-mix(in srgb, currentColor 20%, transparent);
  }
 }
 .zen-library-media-preview-stage {
  display: flex;
  align-items: center;
  justify-content: center;
  height: min(64vh, 620px);
  padding: 16px;
  background: light-dark(rgba(0, 0, 0, 0.05), rgba(0, 0, 0, 0.28));
  border-top: 1px solid light-dark(rgba(0, 0, 0, 0.08), rgba(255, 255, 255, 0.07));
 }
 .zen-library-media-preview-media {
  max-width: 100%;
  max-height: 100%;
  border-radius: 8px;
  object-fit: contain;
 }
@@ -0,0 +1,313 @@
@property --zen-library-progress {
  syntax: "<number>";
  inherits: true;
  initial-value: 0;
 }
 #zen-sidebar-foot-buttons,
 #tabbrowser-tabs {
  --zen-library-open-duration: 0.3s;
  --zen-library-open-easing: cubic-bezier(0.22, 1, 0.36, 1);
  --zen-library-entry-easing: linear(0, 0.34 12%, 0.7 24%, 0.93 38%, 1.03 55%, 1);
  transition: --zen-library-progress var(--zen-library-open-duration) var(--zen-library-open-easing);
  &[zen-library-stack-open] {
    --zen-library-progress: 1;
  }
 }
 #zen-library-button {
  position: relative;
  --zen-library-sprite-size: 18px;
  &::before {
    content: "";
    position: absolute;
    width: var(--zen-library-sprite-size);
    height: var(--zen-library-sprite-size);
    background-image: url("chrome://browser/skin/zen-icons/library/library-sprite.svg");
    scale: 1.08;
  }
  @media (prefers-reduced-motion: no-preference) {
    &::before {
      animation: zen-library-sprite-unhover 0.3s steps(36, jump-none);
    }
    &:hover::before {
      animation: zen-library-sprite-hover 0.35s steps(36, jump-none) forwards;
    }
  }
 }
 #zen-library-button > .toolbarbutton-badge-stack {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  background: none !important;
  pointer-events: none;
  &[downloading] {
    animation: 0.4s library-badge-download ease;
  }
  /* The badge flies from its spot on the button to the newest entry's badge
   * along an arc, the target being set as the list opens. */
  & #library-button-badge {
    position: absolute;
    margin: 0 !important;
    transform-origin: left top;
    --zen-library-badge-x: 14px;
    --zen-library-badge-y: -8px;
    --zen-library-badge-to-x: var(--zen-library-badge-x);
    --zen-library-badge-to-y: var(--zen-library-badge-y);
    --zen-library-badge-mid-x: calc(
      (var(--zen-library-badge-x) + var(--zen-library-badge-to-x)) / 2 +
        abs(var(--zen-library-badge-to-y) - var(--zen-library-badge-y)) / 2
    );
    --zen-library-badge-mid-y: calc(
      (var(--zen-library-badge-y) + var(--zen-library-badge-to-y)) / 2 -
        abs(var(--zen-library-badge-to-x) - var(--zen-library-badge-x)) / 2
    );
    --zen-library-left: calc(1 - var(--zen-library-progress));
    left: calc(
      var(--zen-library-left) * var(--zen-library-left) * var(--zen-library-badge-x) +
        2 * var(--zen-library-left) * var(--zen-library-progress) * var(--zen-library-badge-mid-x) +
        var(--zen-library-progress) * var(--zen-library-progress) * var(--zen-library-badge-to-x)
    );
    top: calc(
      var(--zen-library-left) * var(--zen-library-left) * var(--zen-library-badge-y) +
        2 * var(--zen-library-left) * var(--zen-library-progress) * var(--zen-library-badge-mid-y) +
        var(--zen-library-progress) * var(--zen-library-progress) * var(--zen-library-badge-to-y)
    );
    &:not([downloading]) {
      transform: scale(calc((var(--zen-library-progress) * 0.5 + 0.5) * 100%));
    }
    &[downloading] {
      transform: scale(calc((var(--zen-library-progress) * 0.2 + 0.8) * 100%));
    }
  }
 }
 #library-button-badge,
 #zen-sidebar-foot-buttons[zen-library-badge] #zen-library-download-list > :last-child .zen-library-download-badge {
  visibility: hidden;
 }
 #zen-sidebar-foot-buttons[zen-library-badge] {
  & #library-button-badge {
    visibility: visible;
  }
  &[zen-library-stack-open] {
    & #library-button-badge {
      visibility: hidden;
      transition: visibility 0s var(--zen-library-open-duration);
    }
    & #zen-library-download-list > :last-child .zen-library-download-badge {
      visibility: visible;
      transition: visibility 0s var(--zen-library-open-duration);
    }
  }
 }
 .zen-library-download-badge {
  pointer-events: none;
 }
 .zen-library-download-badge:not([downloading]) {
  background-image: var(--download-image);
  width: 20px;
  height: 20px;
  border-radius: var(--border-radius-xsmall);
  background-size: cover;
  scale: 2;
  & .zen-library-download-progress {
    display: none !important;
  }
 }
 .zen-library-download-badge[downloading] {
  will-change: transform;
  align-self: start;
  transform: translateX(-2px);
  --border-color: color-mix(in srgb, var(--zen-primary-color), light-dark(rgba(0,0,0,.8), white) 70%);
  background-color: color-mix(in srgb, var(--zen-primary-color), light-dark(white, rgba(0,0,0,.5)) 80%);
  border: 3px solid transparent;
  box-shadow: 0 0 6px 2px rgba(0,0,0,.1);
  color: var(--border-color);
  width: 25px;
  height: 25px;
  border-radius: 100%;
  position: relative;
 }
 .zen-library-download-badge[downloading]::after {
  background-image: url("chrome://browser/skin/zen-icons/forward.svg");
  rotate: 90deg;
  position: absolute;
  content: '';
  background-size: contain;
  inset: 2px;
  fill: currentColor;
  -moz-context-properties: fill;
 }
 .zen-library-download-progress {
  position: absolute;
  inset: 1px;
  border-radius: 50%;
  --badge-size: 25px;
  --border-width: 4px;
  --size: calc(var(--badge-size) + 2 * var(--border-width));
  margin: calc(-1 * var(--border-width));
  --thickness: 3px;
  --progress: var(--zen-accent-button-background);
  background:
    conic-gradient(
        from 0deg,
        var(--progress) calc(var(--value) * 1%),
        transparent 0
      )
      border-box,
    var(--border-color) border-box;
  mask: radial-gradient(
    circle closest-side,
    transparent calc(100% - var(--thickness)),
    black calc(100% - var(--thickness))
  );
 }
 #zen-sidebar-foot-buttons:is([zen-library-stack-open], [zen-library-stack-closing]) {
  z-index: 3;
 }
 #zen-library-download-list {
  width: 100%;
  height: auto;
  position: absolute;
  bottom: 100%;
  visibility: hidden;
  transition: visibility 0s var(--zen-library-open-duration);
  #zen-sidebar-foot-buttons[zen-library-stack-open] & {
    visibility: visible;
    transition: none;
  }
  display: flex;
  flex-direction: column;
  padding: 0;
  padding-top: 10px;
  gap: 4px;
  .zen-library-download-list-download {
    container-type: inline-size;
    -moz-window-dragging: no-drag;
    height: 52px;
    border-radius: 16px;
    display: flex;
    position: relative;
    padding: 0 4px;
    --zen-library-progress: 0;
    --zen-library-entry-index: 0;
    --zen-library-entry-delay: calc(var(--zen-library-entry-index) * 12ms);
    --zen-library-entry-settle: 0s;
    transition:
      --zen-library-progress 0.22s var(--zen-library-entry-easing) var(--zen-library-entry-delay),
      pointer-events 0s var(--zen-library-entry-settle) allow-discrete;
    pointer-events: none;
    &:nth-last-child(2) {
      --zen-library-entry-index: 1;
    }
    &:nth-last-child(3) {
      --zen-library-entry-index: 2;
    }
    &:nth-last-child(4) {
      --zen-library-entry-index: 3;
    }
    #zen-sidebar-foot-buttons[zen-library-stack-open] & {
      --zen-library-progress: 1;
      --zen-library-entry-settle: calc(0.22s + var(--zen-library-entry-delay));
      pointer-events: auto;
    }
    transform: translateY(calc((1 - var(--zen-library-progress)) * 25px));
    opacity: var(--zen-library-progress);
    &:hover {
      background: var(--zen-toolbar-element-bg);
    }
    & .zen-library-download-list-title-container {
      @container (max-width: 50px) {
        display: none !important;
      }
      margin: auto 0;
      min-width: 0;
      flex: 1;
      & .zen-library-download-list-title {
        font-size: 11pt;
        opacity: 0.9;
        text-overflow: ellipsis;
        display: block;
        overflow: hidden;
        white-space: nowrap;
      }
      & .zen-library-download-list-subtitle {
        font-size: 9pt;
        opacity: 0.6;
        text-overflow: ellipsis;
        display: block;
        overflow: hidden;
        white-space: nowrap;
      }
    }
    & .zen-library-download-badge {
      margin: auto 20px auto 8px;
      @container (max-width: 50px) {
        margin: auto;
      }
    }
    & .zen-library-download-action {
      display: none;
      margin: auto 4px auto 0;
      @container (max-width: 50px) {
        display: none !important;
      }
    }
    &[downloading] .zen-library-download-action {
      display: flex;
      list-style-image: url("chrome://browser/skin/zen-icons/close.svg");
    }
  }
 }
@@ -17,7 +17,7 @@
 }
 .urlbar {
-  --urlbarview-separator-color: light-dark(hsl(0, 0%, 80%), hsl(0, 0%, 20%));
+  --urlbarview-separator-color: light-dark(rgb(233, 233, 233), rgb(46 46 47));
  --urlbarview-background-color-hover: var(--toolbarbutton-background-color-hover);
  border-radius: calc(var(--toolbarbutton-border-radius) - 2px);
  --urlbarView-results-padding: 10px !important;
@@ -27,6 +27,9 @@
  --urlbar-margin-inline: 5px;
  --urlbar-container-padding: 4px;
  --urlbar-icon-border-radius: 8px !important;
  --urlbar-inner-border-radius: 8px !important;
  &[breakout-extend] {
    --urlbar-container-padding: 0px;
  }
@@ -164,11 +167,12 @@
    }
    #navigator-toolbox[zen-has-implicit-hover="true"] &,
-    &[open],
+    &:is([open], [showing]),
    #urlbar[has-popup-open="true"] &,
    :root[zen-has-empty-tab="true"] & {
      opacity: 1;
      visibility: visible;
      transition: opacity 0.15s !important;
    }
  }
 }
@@ -273,29 +277,31 @@
  }
  & .urlbar-background {
-    --zen-urlbar-background-base: light-dark(#fbfbfb, color-mix(in srgb, hsl(0, 0%, 6.7%), var(--zen-colors-primary) 30%));
+    --zen-urlbar-background-base: light-dark(rgb(255, 255, 255), rgb(24 24 24));
    /* stylelint-disable-next-line media-query-no-invalid */
    @media -moz-pref("zen.theme.acrylic-elements") and (not (prefers-reduced-transparency: reduce)) {
-      --zen-urlbar-background-transparent: light-dark(
+      &:not(:-moz-window-inactive) { 
-        color-mix(in srgb, white 80%, transparent),
+        --zen-urlbar-background-transparent: light-dark(
-        color-mix(in srgb, var(--zen-urlbar-background-base) 65%, transparent)
+          rgba(255, 255, 255, .93),
-      );
+          rgba(20, 20, 20, .93)
        );
      }
    }
    background-color: var(--zen-urlbar-background-transparent, var(--zen-urlbar-background-base)) !important;
    box-shadow: 0 30px 140px -15px light-dark(rgba(0, 0, 0, 0.8), rgba(0, 0, 0, 0.6)) !important;
    backdrop-filter: none !important;
-    outline: 0.5px solid light-dark(rgba(0, 0, 0, 0.2), rgba(255, 255, 255, 0.2)) !important;
+    outline: 0.5px solid light-dark(rgba(0, 0, 0, 0.2), rgb(75, 75, 75)) !important;
    outline-offset: var(--zen-urlbar-outline-offset) !important;
    /* stylelint-disable-next-line media-query-no-invalid */
    @media -moz-pref("zen.theme.acrylic-elements") {
-      backdrop-filter: var(--zen-urlbar-filter) !important;
+      backdrop-filter: var(--zen-backdrop-underlay) blur(40px) !important;
    }
  }
  &,
  .urlbar-background {
-    border-radius: 12px !important;
+    border-radius: 15px !important;
  }
  &[breakout-extend][animate-searchmode="true"]::before {
@@ -315,9 +321,6 @@
 }
 :root[zen-single-toolbar="true"] {
  --urlbar-icon-border-radius: 8px !important;
  --urlbar-inner-border-radius: 6px !important;
  #identity-permission-box > *:not(#zen-site-data-icon-button) {
    visibility: collapse;
  }
@@ -509,7 +512,7 @@
 #urlbar[open][zen-floating-urlbar="true"] #identity-icon-box,
 :root[zen-single-toolbar="true"] #urlbar[breakout-extend] #identity-icon-box {
  --urlbar-box-hover-bgcolor: transparent;
-  margin-inline: 2px 8px;
+  margin-inline: 2px 4px;
  transition: none;
 }
@@ -535,8 +538,8 @@
 .urlbarView-favicon {
  margin-left: 0 !important;
  margin-right: 12px !important;
-  padding: 6px !important;
+  padding: 4px !important;
-  border-radius: 3px !important;
+  border-radius: 4px !important;
 }
 .urlbarView-userContext {
@@ -558,22 +561,24 @@
 }
 .urlbarView-prettyName,
 .urlbarView-tabGroup,
 .urlbarView-shortcutContent {
-  border-radius: 4px;
+  border-radius: 4px !important;
  font-weight: 600;
-  margin-top: auto;
+  margin-top: auto !important;
-  margin-bottom: auto;
+  margin-bottom: auto !important;
 }
-.urlbarView-prettyName {
+.urlbarView-prettyName,
-  padding: 4px 6px;
+.urlbarView-tabGroup {
-  background-color: color-mix(in srgb, var(--zen-branding-bg-reverse), transparent 90%);
+  padding: 4px 6px !important;
-  margin-left: 6px;
+  background-color: color-mix(in srgb, var(--zen-branding-bg-reverse), transparent 90%) !important;
  margin-left: 6px !important;
  font-size: 12px;
  align-items: center;
  gap: 6px;
  display: flex;
-  color: color-mix(in srgb, var(--zen-primary-color), currentColor 95%);
+  color: color-mix(in srgb, var(--zen-primary-color), currentColor 95%) !important;
  & img {
    -moz-context-properties: fill;
@@ -649,18 +654,19 @@
 .urlbarView-row {
  --urlbarView-row-padding-inline: 8px;
-  --urlbarview-row-padding-block: 10px;
+  --urlbarview-row-padding-block: 12px;
  --urlbarView-row-gutter: 0px;
  color: light-dark(rgba(0, 0, 0, 0.7), rgba(255, 255, 255, 0.7)) !important;
-  &:hover {
+  &:hover,
-    &,
+  &:hover .urlbarView-favicon,
-    & .urlbarView-favicon {
+  .urlbarView-action-favicon {
-      background-color: color-mix(in srgb, var(--zen-branding-bg-reverse) 5%, transparent 95%) !important;
+    background-color: color-mix(in srgb, var(--zen-branding-bg-reverse) 5%, transparent 95%) !important;
    }
  }
  &[selected] {
-    --zen-selected-bg: color-mix(in srgb, var(--zen-primary-color) 50%, light-dark(rgba(0, 0, 0, 0.5), rgba(255, 255, 255, 0.1)));
+    --zen-selected-bg: color-mix(in srgb, var(--zen-primary-color) 50%, light-dark(rgba(0, 0, 0, 0.3), rgba(255, 255, 255, 0.1)));
    --zen-selected-color: color-mix(in srgb, var(--zen-selected-bg), black 30%);
    background-color: var(--zen-selected-bg) !important;
@@ -684,14 +690,15 @@
      background-color: rgba(255, 255, 255, 0.9) !important;
    }
-    & .urlbarView-prettyName {
+    & .urlbarView-prettyName,
-      background-color: color-mix(in srgb, var(--zen-branding-bg-reverse), transparent 80%);
+    & .urlbarView-tabGroup {
      background-color: color-mix(in srgb, var(--zen-branding-bg-reverse), transparent 80%) !important;
    }
  }
 }
 #urlbar-results {
-  max-height: 252px;
+  max-height: 244px;
  overflow-y: auto;
  scrollbar-width: none;
  margin-block-start: calc(var(--urlbarView-results-padding) - 2px);
@@ -30,6 +30,14 @@ panel[type="arrow"]:not(#feature-callout) {
    }
  }
  @media (-moz-platform: linux) or ((-moz-platform: windows) and (not (-moz-windows-mica-popups))) {
    &::part(content) {
      /* stylelint-disable-next-line property-no-unknown */
      corner-shape: round; 
      border-radius: calc(var(--panel-border-radius) / var(--zen-squircle-value));
    }
  }
  @media (-moz-platform: macos) {
    &:is([nonnative], :not([type="arrow"])) {
      appearance: auto !important;
@@ -64,6 +64,10 @@ hbox.editBMPanel_folderRow {
  margin-right: 10px;
 }
 #editBMPanel_workspaceSummary .workspace-trigger {
  margin-inline-end: 16px;
 }
 /* Bookmarks in toolbar */
 #PersonalToolbar {
  background: transparent;
@@ -411,3 +411,7 @@ menuseparator {
 #window-modal-dialog {
  inset: 0;
 }
 .tab-preview-thumbnail-container > canvas {
  border-radius: calc(var(--border-radius-medium) / var(--zen-squircle-value));
 }
@@ -800,3 +800,16 @@
    display: none;
  }
 }
 #tabbrowser-tabs:is([zen-library-stack-open], [zen-library-stack-closing]) {
  --gradient-pos: calc(100% - var(--zen-library-stack-height, 0px) + 20px);
  mask-image: linear-gradient(
    to bottom,
    black
      calc(var(--gradient-pos) - 50px),
    color-mix(transparent calc(var(--zen-library-progress) * 100%), black)
      var(--gradient-pos));
 }
 %include zen-library-widget.css
 %include zen-library-media-preview.css
@@ -101,7 +101,7 @@
  ) !important;
  --focus-outline-color: var(--color-accent-primary) !important;
-  --toolbarbutton-icon-fill-attention: var(--toolbar-color) !important;
+  --toolbarbutton-icon-fill-attention: var(--toolbar-color, currentColor) !important;
  --toolbarbutton-icon-fill: currentColor !important;
  --button-background-color-primary: var(--in-content-primary-button-background) !important;
@@ -220,7 +220,7 @@
  --zen-squircle-value: 1.3;
  @media (-moz-platform: windows) {
-    --zen-squircle-value: 2.1;
+    --zen-squircle-value: 2.3;
  }
  --tab-icon-overlay-stroke: light-dark(white, black) !important;
@@ -303,7 +303,7 @@
  }
 }
-#main-window[windowtype="navigator:browser"]:not([chromehidden~='toolbar']) {
+#main-window[windowtype="navigator:browser"]:not([popup-window]) {
  min-height: 495px !important;
  @media (-moz-windows-mica) or (-moz-platform: macos) or ((-moz-platform: linux) and
@@ -361,4 +361,6 @@
  .zen-squircle-after::after {
    corner-shape: superellipse(var(--zen-squircle-value));
  }
 %include squircle-exclusions.inc.css
 }
@@ -42,7 +42,6 @@ let JSWINDOWACTORS = {
    child: {
      esModuleURI: "resource:///actors/ZenGlanceChild.sys.mjs",
      events: {
        DOMContentLoaded: {},
        mousedown: {
          capture: true,
        },
@@ -86,9 +85,7 @@ if (!Services.appinfo.inSafeMode) {
    child: {
      esModuleURI: "resource:///actors/ZenBoostsChild.sys.mjs",
      events: {
-        // Needed to let the actor be created, please don't remove
+        DOMDocElementInserted: {},
        // without checking if boosts still work without it, thanks <3
        DOMWindowCreated: {},
      },
    },
    safeForUntrustedWebProcess: true,
@@ -4,17 +4,25 @@
 import { AppConstants } from "resource://gre/modules/AppConstants.sys.mjs";
 const lazy = {};
 ChromeUtils.defineESModuleGetters(lazy, {
  ZenLibraryWidget: "moz-src:///zen/library/ZenLibraryWidget.sys.mjs",
 });
 export const ZenCustomizableUI = new (class {
  constructor() {}
  TYPE_TOOLBAR = "toolbar";
  defaultSidebarIcons = [
-    "downloads-button",
+    Services.prefs.getBoolPref("zen.library.enabled")
      ? "zen-library-button"
      : "downloads-button",
    "zen-workspaces-button",
    "zen-create-new-button",
  ];
  startup(CustomizableUIInternal) {
    CustomizableUIInternal.createBuiltinWidget(lazy.ZenLibraryWidget);
    CustomizableUIInternal.registerArea(
      "zen-sidebar-top-buttons",
      {
@@ -7,12 +7,15 @@ import { AppConstants } from "resource://gre/modules/AppConstants.sys.mjs";
 const lazy = {};
 ChromeUtils.defineESModuleGetters(lazy, {
-  SessionStore: "resource:///modules/sessionstore/SessionStore.sys.mjs",
+  CustomizableUI:
    "moz-src:///browser/components/customizableui/CustomizableUI.sys.mjs",
  SessionStore:
    "moz-src:///browser/components/sessionstore/SessionStore.sys.mjs",
 });
 class nsZenUIMigration {
  PREF_NAME = "zen.ui.migration.version";
-  MIGRATION_VERSION = 7;
+  MIGRATION_VERSION = 8;
  init(isNewProfile) {
    if (!isNewProfile) {
@@ -22,6 +25,7 @@ class nsZenUIMigration {
        console.error("ZenUIMigration: Error during migration", e);
      }
    }
    this.#migrateLibraryButton();
    this.clearVariables();
    if (this.shouldRestart) {
      Services.startup.quit(
@@ -50,6 +54,41 @@ class nsZenUIMigration {
    this._migrationVersion = this.MIGRATION_VERSION;
  }
  #migrateLibraryButton() {
    const donePref = "zen.library.migrated-downloads-button";
    if (
      !Services.prefs.getBoolPref("zen.library.enabled", false) ||
      Services.prefs.getBoolPref(donePref, false)
    ) {
      return;
    }
    // A toolbar's saved placements are only there once a window has it.
    const footButtons = "zen-sidebar-foot-buttons";
    const listener = {
      onAreaNodeRegistered: area => {
        if (area !== footButtons) {
          return;
        }
        lazy.CustomizableUI.removeListener(listener);
        Services.prefs.setBoolPref(donePref, true);
        const downloads =
          lazy.CustomizableUI.getPlacementOfWidget("downloads-button");
        if (
          downloads?.area === footButtons &&
          !lazy.CustomizableUI.getPlacementOfWidget("zen-library-button")
        ) {
          lazy.CustomizableUI.addWidgetToArea(
            "zen-library-button",
            footButtons,
            downloads.position
          );
          lazy.CustomizableUI.removeWidgetFromArea("downloads-button");
        }
      },
    };
    lazy.CustomizableUI.addListener(listener);
  }
  _migrateV1() {
    // If there's an userChrome.css or userContent.css existing, we set
    // 'toolkit.legacyUserProfileCustomizations.stylesheets' back to true
@@ -164,6 +203,18 @@ class nsZenUIMigration {
      Services.prefs.setBoolPref("zen.widget.macos.window-vibrancy", false);
    }
  }
  _migrateV8() {
    // A version mismatch in the downloadable gfx blocklist wrongly blocked
    // video overlays for every Windows user. The status pref persists in the
    // profile and short-circuits the blocklist evaluation, so clear it (and
    // its failure id) and restart, since gfx is already initialized by now.
    if (Services.prefs.prefHasUserValue("gfx.blacklist.video-overlay")) {
      Services.prefs.clearUserPref("gfx.blacklist.video-overlay");
      Services.prefs.clearUserPref("gfx.blacklist.video-overlay.failureid");
      this.shouldRestart = true;
    }
  }
 }
 export var gZenUIMigration = new nsZenUIMigration();
@@ -41,6 +41,9 @@ document.addEventListener(
          case "cmd_zenSplitViewContextMenu":
            gZenViewSplitter.contextSplitTabs();
            break;
          case "cmd_zenCtxShareSplitView":
            gZenViewSplitter.contextShareSplitView();
            break;
          case "cmd_zenCopyCurrentURLMarkdown":
            gZenCommonActions.copyCurrentURLAsMarkdownToClipboard();
            break;
@@ -90,6 +93,9 @@ document.addEventListener(
          case "cmd_zenCtxDeleteWorkspace":
            gZenWorkspaces.contextDeleteWorkspace(event);
            break;
          case "cmd_zenCtxShareWorkspace":
            gZenWorkspaces.contextShareWorkspace();
            break;
          case "cmd_zenChangeWorkspaceName":
            gZenVerticalTabsManager.renameTabStart({
              target: gZenWorkspaces.activeWorkspaceIndicator.querySelector(
@@ -154,12 +160,20 @@ document.addEventListener(
          }
          case "cmd_zenDuplicateTab": {
            const selectedTabs = gBrowser.selectedTabs;
-            let insertAt = selectedTabs.at(-1)._tPos + 1;
+            let insertAt = selectedTabs.at(-1).index + 1;
            for (const tab of selectedTabs) {
              gBrowser.duplicateTab(tab, true, { tabIndex: insertAt++ });
            }
            break;
          }
          case "cmd_zenToggleLibrary": {
            const { ZenLibrary } = ChromeUtils.importESModule(
              "moz-src:///zen/library/ZenLibrary.mjs",
              { global: "current" }
            );
            ZenLibrary.toggle();
            break;
          }
          default:
            gZenGlanceManager.handleMainCommandSet(event);
            if (event.target.id.startsWith("cmd_zenWorkspaceSwitch")) {
@@ -109,7 +109,7 @@
        if (AppConstants.platform == "macosx") {
          const targetRadius = window.matchMedia("(-moz-mac-tahoe-theme)")
            .matches
-            ? 12
+            ? 11
            : 10;
          document.documentElement.style.setProperty(
            "--zen-border-radius",
@@ -125,7 +125,7 @@
          // Windows defaults to 8px
          document.documentElement.style.setProperty(
            "--zen-border-radius",
-            "8px"
+            "9px"
          );
        }
      } else {
@@ -61,6 +61,12 @@ ChromeUtils.defineLazyGetter(lazy, "mainAppWrapper", () =>
  document.getElementById("zen-main-app-wrapper")
 );
 ChromeUtils.defineESModuleGetters(
  lazy,
  { ZenLibrary: "moz-src:///zen/library/ZenLibrary.mjs" },
  { global: "current" }
 );
 window.gZenCompactModeManager = {
  _flashTimeouts: {},
  _eventListeners: [],
@@ -165,12 +171,13 @@ window.gZenCompactModeManager = {
  },
  get shouldBeCompact() {
-    return !document.documentElement
+    return !document.documentElement.hasAttribute("popup-window");
      .getAttribute("chromehidden")
      ?.includes("toolbar");
  },
  set preference(value) {
    if (lazy.ZenLibrary.isLibrarySlightlyOpen) {
      return;
    }
    if (!this.shouldBeCompact) {
      value = false;
    }
@@ -477,9 +484,9 @@ window.gZenCompactModeManager = {
    document.documentElement.setAttribute("zen-compact-animating", "true");
    return new Promise(resolve => {
      // We need to set the splitter width before hiding it
-      let splitterWidth = document
+      let splitterWidth = window.windowUtils.getBoundsWithoutFlushing(
-        .getElementById("zen-sidebar-splitter")
+        document.getElementById("zen-sidebar-splitter")
-        .getBoundingClientRect().width;
+      ).width;
      const isCompactMode = this.preference;
      const canHideSidebar = this.canHideSidebar;
      let canAnimate =
@@ -543,7 +550,7 @@ window.gZenCompactModeManager = {
                ease: "easeIn",
                type: "spring",
                bounce: 0,
-                duration: 0.12,
+                duration: 0.1,
              }
            )
            .then(() => {
@@ -599,7 +606,7 @@ window.gZenCompactModeManager = {
                ease: "easeOut",
                type: "spring",
                bounce: 0,
-                duration: 0.12,
+                duration: 0.1,
              }
            )
            .then(() => {
@@ -864,7 +871,6 @@ window.gZenCompactModeManager = {
              "supress-primary-adjustment"
            ) === "true" &&
              gZenVerticalTabsManager._hasSetSingleToolbar) ||
            this._hasHoveredUrlbar ||
            this._ignoreNextHover ||
            (event.type === "dragleave" &&
              event.explicitOriginalTarget !== target &&
@@ -877,7 +883,10 @@ window.gZenCompactModeManager = {
            return;
          }
-          if (this.hoverableElements[i].keepHoverDuration) {
+          if (
            this.hoverableElements[i].keepHoverDuration &&
            !this._hasHoveredUrlbar
          ) {
            this.flashElement(
              target,
              this.hoverableElements[i].keepHoverDuration,
--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
mr. m	4c92731b2d	gh-15512: Sync upstream Firefox to version `156.0.1` (gh-15515)	2026-09-22 15:45:14 +02:00
mr. m	be04ad6d50	gh-15513: URL bar and sidebar should have transparency when available (gh-15514)	2026-09-22 14:08:20 +02:00
fen4flo	f0f21cdade	gh-15438: Fix library compact mode offset (gh-15504)	2026-09-21 20:00:10 +02:00
fen4flo	e68b5e5c26	gh-15438: Fix library compact mode animation (gh-15502)	2026-09-21 16:52:29 +02:00
mr. m	7545e5a870	gh-15460: Fixed folder expansion expanding real folders on library (gh-15498)	2026-09-21 16:51:05 +02:00
mr. m	b3467c0ff2	gh-15494: Fixed library media tab freezing (gh-15495)	2026-09-21 01:43:48 +02:00
fen4floandmr. m	303b6e39ed	gh-15438: Performance optimizations and media tab for Library (gh-15483) Co-authored-by: mr. m <91018726+mr-cheffy@users.noreply.github.com> Signed-off-by: fen4flo <75260616+FlorianButz@users.noreply.github.com>	2026-09-20 22:08:51 +02:00
mr. m	7debd15013	gh-15489: Fixed closing a window not swiping browser views (gh-15490)	2026-09-20 11:55:02 +02:00
mr. m	450aeeccd3	gh-15380: Fixed not identifying applied stamps correctly (gh-15485)	2026-09-19 20:42:51 +02:00
mr. m	8645a5b9c8	gh-15462: Fixed broken folder animations for library (gh-15467)	2026-09-18 16:40:31 +02:00
mr. m	031b5d8d0a	gh-15426: Fixed spaces wiping if zen is opened on other devices (gh-15458)	2026-09-18 16:27:05 +02:00
mr. m	2804ba8350	gh-15445: Fixed visibility checks for popup notifications (gh-15455)	2026-09-18 09:29:37 +02:00
Batan Alex	5e5926e708	gh-15374: Remove squircle multiplier from thumbnail's border radius (gh-15452)	2026-09-18 08:30:49 +02:00
mr. m	a65f96c3b8	gh-15448: Fixed various library issues (gh-15451)	2026-09-18 00:40:09 +02:00
mr. m	4b4a659c7b	gh-15437: Fixed command actions on the urlbar not working (gh-15449)	2026-09-18 00:37:43 +02:00
Batan Alex	5ff06e4274	gh-15374: Fix incorrect tab preview thumbnail border radius (gh-15444) Signed-off-by: Batan Alex <batan_alex@icloud.com>	2026-09-17 23:19:57 +02:00
Andrey Bochkarev	f31f99e507	gh-15293: Fix tab index calculation for CWLO (gh-15446)	2026-09-17 21:41:37 +02:00
fen4floandmr. m	2ee1275f28	gh-15438: Implementing Zen Library (gh-15282) Co-authored-by: mr. m <91018726+mr-cheffy@users.noreply.github.com> Signed-off-by: mr. m <91018726+mr-cheffy@users.noreply.github.com>	2026-09-17 15:03:20 +02:00
Andrey Bochkarev	45b9cfe37f	gh-15419: Fix overflow-extension order in single toolbar mode (gh-15420)	2026-09-17 14:54:22 +02:00
mr. m	f800d550cb	gh-15422: Fixed broken folder animations (gh-15436)	2026-09-17 14:53:29 +02:00
mr. m	04e7db5d3a	gh-15384: Sync upstream Firefox to version `156.0` (gh-15409)	2026-09-15 23:06:35 +02:00
mr. m	644bf48b6c	gh-13196: Fixed sidebar not hiding if the urlbar is open (gh-15403)	2026-09-14 20:56:36 +02:00
Kyle Montag	d2acc61a88	gh-15402: Add `archived:false` to github live folder queries (gh-14854) Signed-off-by: Kyle Montag <KMontag42@users.noreply.github.com>	2026-09-14 19:52:56 +02:00
mr. m	f84278317f	gh-15400: Fixed duplicate `paste and go` items (gh-15401)	2026-09-14 15:03:58 +02:00
Alain Stulzandmr. m	4980f3ce18	gh-10577: Add various requested url bar actions (gh-15376) Co-authored-by: mr. m <91018726+mr-cheffy@users.noreply.github.com> Signed-off-by: Alain Stulz <ast3150@gmail.com>	2026-09-14 09:42:23 +02:00
Patrick Wozniakandmr. m	5362ddbccd	gh-14171: Fix cross-space routing tab lifecycle races (gh-14832) Co-authored-by: mr. m <91018726+mr-cheffy@users.noreply.github.com>	2026-09-14 09:27:31 +02:00
mr. m	6c32eaad68	gh-15384: Fix windows builds for Firefox `156.0` (gh-15399)	2026-09-14 02:33:15 +02:00
mr. m	610e7bfbae	gh-15384: Sync upstream Firefox to version `156.0` (gh-15385)	2026-09-14 01:33:43 +02:00
doruk	b43785de65	gh-15387: Fix #writeToDom crash when mod has checkbox preferences (gh-15388)	2026-09-14 01:33:21 +02:00
Ashvin Jangid	787f9c5e02	gh-15393: Remove corner-shape from loading-progress-bar and statuspanel (gh-15394)	2026-09-13 13:19:49 +02:00
doruk	22961e97d8	gh-15363: Fix boost font shuffle off-by-one index (gh-15365)	2026-09-11 14:35:24 +02:00
mr. m	cb6a607c67	gh-15362: Prevent window captions appearing as squircles (gh-15364)	2026-09-11 14:25:26 +02:00
mr. m	267c9aabe1	gh-15353: Prevent popups from being too rounded on linux (gh-15354)	2026-09-11 09:37:47 +02:00
doruk	d54e12359c	gh-15355: Fix folder unload TypeError by using String.includes (gh-15347)	2026-09-11 09:37:37 +02:00
mr. m	c89645a787	gh-15344: Fixed restoring tabs with static icons being cleared (gh-15345)	2026-09-11 01:23:58 +02:00
mr. m	0a548c7572	gh-15329: Prevent split view preview from opening for multiple tabs (gh-15340)	2026-09-10 22:20:12 +02:00
mr. m	6d158223b5	gh-15123: Fixed not spawining any native messaging host (gh-15328)	2026-09-10 10:47:35 +02:00
mr. m	76fcd5c822	gh-15026: Revert "Improve scrolling performance" (gh-15327)	2026-09-10 10:32:48 +02:00
Brandon Quon	ed6900d762	gh-14938: Fix CWLO for only pinned/essential tabs (gh-15324)	2026-09-10 10:27:53 +02:00
mr. m	2e9aecd41b	gh-6302: Remove corner shape for browser stack rendering (gh-15318)	2026-09-09 19:35:46 +02:00
mr. m	da995e8653	gh-15313: Make sure to bootstrap before doing release builds (gh-15314)	2026-09-09 13:15:17 +02:00
mr. m	64d73ab3e3	gh-14956: Check if the closing tab exists on the tab list before switching (gh-15312)	2026-09-09 13:13:40 +02:00
Brandon Quonandmr. m	9551444c61	gh-15260: Fix essentials appearing during workspace creation (gh-15307) Co-authored-by: mr. m <mr.m@tuta.com>	2026-09-09 08:34:59 +02:00
mr. m	fdf9588b7b	gh-15026: Improve scrolling performance (gh-15306)	2026-09-09 02:13:38 +02:00
mr. m	b07b17c87e	gh-15304: Revert urlbar when searching with an alias (gh-15305)	2026-09-09 01:39:13 +02:00
mr. m	c9d3cb3dc9	gh-15297: Fixed synced tabs losing their icon when they are unloaded (gh-15298)	2026-09-08 20:14:23 +02:00
KiKaraage	2c030369c5	gh-15288: add missing margin for space selector in BMPanel (gh-15286) Signed-off-by: KiKaraage <kikaraage@tuta.io>	2026-09-08 18:48:07 +02:00
Brandon Quon	88a90206ce	gh-14755: fix duplicated owned tabs leaving folders (gh-15285)	2026-09-08 18:24:10 +02:00
Andrey Bochkarev	6d398dec63	gh-15295: Correct tab index calculation for CWLO (gh-15293)	2026-09-08 18:22:23 +02:00
mr. m	243a8791a0	gh-15279: Wait for all windows to be restored before syncing (gh-15294)	2026-09-08 18:13:33 +02:00
Brandon Quon	412731f37e	gh-15155: Fix tab moving to bottom of tab list (gh-15246)	2026-09-07 22:54:02 +02:00
mr. m	7a78848177	gh-15266: Add support for sharing spaces, folders and split views (gh-15283)	2026-09-07 22:28:09 +02:00
mr. m	a323036995	gh-15266: Add support for sharing spaces, folders and split views (gh-15267)	2026-09-07 01:11:02 +02:00
Harsh Varshney	abc69a1fcb	gh-15188: Fixed invisible download progress bar in Library when unselected (gh-15251) Signed-off-by: Harsh Varshney <92783708+Iron0utlaw@users.noreply.github.com>	2026-09-06 17:52:30 +02:00
mr. m	8df45e5c9a	gh-15247: Add support for cross-device normal tabs (gh-15250)	2026-09-06 02:42:59 +02:00
mr. m	58e83c137f	gh-15244: Fixed creatin a new space not selecting the empty tab (gh-15245)	2026-09-05 20:25:24 +02:00
		`@@ -1 +1 @@`
			`b6d45eac914fd4886c9b6e5f1447f613771228ff`				`782b15a7c771795a323e9403340c029e7c8d7629`