diff --git a/browser/components/tabbrowser/content/tab.js b/browser/components/tabbrowser/content/tab.js
index 8f2ebf3a0bd4e2af01cf41024b16bd491e8ed961..27721e26c3cd8cb066b462dedfa4ce785ca5c2c3 100644
--- a/browser/components/tabbrowser/content/tab.js
+++ b/browser/components/tabbrowser/content/tab.js
@@ -21,6 +21,7 @@
           <hbox class="tab-group-line"/>
         </vbox>
         <hbox class="tab-content" align="center">
+          <box class="tab-reset-pin-button" role="button" data-l10n-id="tabbrowser-reset-pin-button" data-l10n-args='{"tabCount": 1}' keyNav="false"><image/></box>
           <stack class="tab-icon-stack">
             <hbox class="tab-throbber"/>
             <hbox class="tab-icon-pending"/>
@@ -35,9 +36,11 @@
                 pack="center"
                 flex="1">
             <label class="tab-text tab-label" role="presentation"/>
+            <label class="zen-tab-sublabel" data-l10n-id="zen-tab-sublabel" data-l10n-args='{"tabSubtitle": "zen-default-pinned"}' role="presentation"/>
           </vbox>
           <image class="tab-note-icon" role="presentation"/>
           <image class="tab-close-button close-icon" role="button" data-l10n-id="tabbrowser-close-tabs-button" data-l10n-args='{"tabCount": 1}' keyNav="false"/>
+          <image class="tab-reset-button reset-icon" role="button" data-l10n-id="tabbrowser-unload-tab-button" data-l10n-args='{"tabCount": 1}' keyNav="false"/>
         </hbox>
       </stack>
       `;
@@ -84,7 +87,7 @@
         ".tab-content":
           "pinned,selected=visuallyselected,multiselected,titlechanged,attention",
         ".tab-icon-stack":
-          "sharing,pictureinpicture,crashed,busy,soundplaying,soundplaying-scheduledremoval,pinned,muted,blocked,selected=visuallyselected,activemedia-blocked",
+          "zen-essential,sharing,pictureinpicture,crashed,busy,soundplaying,soundplaying-scheduledremoval,pinned,muted,blocked,selected=visuallyselected,activemedia-blocked",
         ".tab-throbber":
           "fadein,pinned,busy,progress,selected=visuallyselected",
         ".tab-icon-pending":
@@ -93,9 +96,9 @@
           "src=image,requestcontextid,fadein,pinned,selected=visuallyselected,busy,crashed,sharing,pictureinpicture,pending,discarded",
         ".tab-sharing-icon-overlay": "sharing,selected=visuallyselected,pinned",
         ".tab-icon-overlay":
-          "sharing,pictureinpicture,crashed,busy,soundplaying,soundplaying-scheduledremoval,pinned,muted,blocked,selected=visuallyselected,activemedia-blocked",
+          "zen-essential,sharing,pictureinpicture,crashed,busy,soundplaying,soundplaying-scheduledremoval,pinned,muted,blocked,selected=visuallyselected,activemedia-blocked",
         ".tab-audio-button":
-          "crashed,soundplaying,soundplaying-scheduledremoval,pinned,muted,activemedia-blocked",
+          "zen-essential,crashed,soundplaying,soundplaying-scheduledremoval,pinned,muted,activemedia-blocked",
         ".tab-label-container":
           "pinned,selected=visuallyselected,labeldirection",
         ".tab-label":
@@ -184,7 +187,7 @@
     }
 
     set _visuallySelected(val) {
-      if (val == this.hasAttribute("visuallyselected")) {
+      if (val == this.hasAttribute("visuallyselected") || (!val && this.linkedBrowser?.closest('.browserSidebarContainer').classList.contains('zen-glance-background'))) {
         return;
       }
 
@@ -220,11 +223,25 @@
     }
 
     get visible() {
-      return (
-        this.isOpen &&
-        !this.hidden &&
-        (!this.group || this.group.isTabVisibleInGroup(this))
-      );
+      if (!this.isOpen || this.hidden || this.hasAttribute("zen-empty-tab")) {
+        return false;
+      }
+      // Selected tabs are always visible
+      if (this.selected || this.multiselected) return true;
+      // Recursively check all parent groups
+      let currentParent = this.group;
+      while (currentParent) {
+        if (currentParent.collapsed && !currentParent.activeTabs?.includes(this)) {
+          return false;
+        }
+        currentParent = currentParent.group;
+      }
+      if (this.pinned && !this.hasAttribute("zen-essential") &&
+          gZenWorkspaces.activeWorkspaceElement?.hasCollapsedPinnedTabs &&
+          !gZenWorkspaces.activeWorkspaceElement.collapsiblePins.activeTabs?.includes(this)) {
+        return false;
+      }
+      return true;
     }
 
     get hidden() {
@@ -303,7 +320,7 @@
         return false;
       }
 
-      return true;
+      return !this.hasAttribute("zen-empty-tab");
     }
 
     get lastAccessed() {
@@ -388,7 +405,18 @@
     }
 
     get group() {
-      return this.closest("tab-group");
+      if (typeof gBrowser === "undefined") {
+        return null;
+      }
+      if (gBrowser.isTabGroup(this.parentElement?.parentElement)) {
+        return this.parentElement.parentElement;
+      }
+      if (this.pinned && !this.hasAttribute('zen-essential')) {
+        let collapsiblePins = gZenWorkspaces.workspaceElement(this.getAttribute('zen-workspace-id'))?.collapsiblePins;
+        if (collapsiblePins?.collapsed) {
+          return collapsiblePins;
+        }
+      }
     }
 
     get splitview() {
@@ -470,6 +498,10 @@
         }
       }
 
+      if (event.target.classList.contains("tab-reset-pin-button")) {
+        gZenPinnedTabManager.onResetPinButtonMouseOver(this, event);
+      }
+
       // If the previous target wasn't part of this tab then this is a mouseenter event.
       if (!this.contains(event.relatedTarget)) {
         this._mouseenter();
@@ -499,6 +531,7 @@
       if (!this.contains(event.relatedTarget)) {
         this._mouseleave();
       }
+      gZenPinnedTabManager.onResetPinButtonMouseOut(this);
     }
 
     on_dragstart(event) {
@@ -533,6 +566,8 @@
         this.style.MozUserFocus = "ignore";
       } else if (
         event.target.classList.contains("tab-close-button") ||
+        event.target.classList.contains("tab-reset-button") ||
+        event.target.classList.contains("tab-reset-pin-button") ||
         event.target.classList.contains("tab-icon-overlay") ||
         event.target.classList.contains("tab-audio-button")
       ) {
@@ -567,7 +602,7 @@
           }
         } else if (
           event.altKey &&
-          Services.prefs.getBoolPref("browser.tabs.splitView.enabled", false)
+          true
         ) {
           eventMaySelectTab = false;
         } else if (!this.selected && this.multiselected) {
@@ -592,6 +627,10 @@
       this.style.MozUserFocus = "";
     }
 
+    get glanceTab() {
+      return this.querySelector("tab[zen-glance-tab]");
+    }
+
     on_click(event) {
       if (event.button != 0) {
         return;
@@ -615,14 +654,31 @@
             trigger: "alt_click",
           });
         }
+        if (
+          !event.target.classList.contains("tab-close-button") &&
+          !event.target.classList.contains("tab-icon-overlay") &&
+          !event.target.classList.contains("tab-audio-button") &&
+          Services.prefs.getBoolPref("zen.splitView.enable-tab-click-split", false)
+        ) {
+          if (!this.splitView) {
+            gZenViewSplitter.contextSplitTabs(this);
+          } else {
+            gBrowser.selectedTab = this;
+            gZenViewSplitter.removeTabFromGroup(this, undefined, {
+              forUnsplit: true,
+              changeTab: false
+            });
+          }
+        }
         return;
       }
 
-      if (event.getModifierState("Accel") || event.shiftKey) {
+      if (event.shiftKey) {
         return;
       }
 
       if (
+        !event.getModifierState("Accel") &&
         gBrowser.multiSelectedTabsCount > 0 &&
         !event.target.classList.contains("tab-close-button") &&
         !event.target.classList.contains("tab-icon-overlay") &&
@@ -634,8 +690,9 @@
       }
 
       if (
-        event.target.classList.contains("tab-icon-overlay") ||
-        event.target.classList.contains("tab-audio-button")
+        !event.getModifierState("Accel") &&
+        (event.target.classList.contains("tab-icon-overlay") ||
+        event.target.classList.contains("tab-audio-button"))
       ) {
         if (this.activeMediaBlocked) {
           if (this.multiselected) {
@@ -653,7 +710,7 @@
         return;
       }
 
-      if (event.target.classList.contains("tab-close-button")) {
+      if (!event.getModifierState("Accel") && event.target.classList.contains("tab-close-button")) {
         if (this.multiselected) {
           gBrowser.removeMultiSelectedTabs(
             lazy.TabMetrics.userTriggeredContext(
@@ -673,6 +730,14 @@
         // (see tabbrowser-tabs 'click' handler).
         gBrowser.tabContainer._blockDblClick = true;
       }
+
+      if (event.target.classList.contains("tab-reset-pin-button")) {
+        gZenPinnedTabManager._onTabResetPinButton(event, this, 'reset');
+        gBrowser.tabContainer._blockDblClick = true;
+      } else if (!event.getModifierState("Accel") && event.target.classList.contains("tab-reset-button")) {
+        gZenPinnedTabManager.onCloseTabShortcut(event, this);
+        gBrowser.tabContainer._blockDblClick = true;
+      }
     }
 
     on_dblclick(event) {
@@ -696,6 +761,8 @@
           animate: true,
           triggeringEvent: event,
         });
+      } else if (this.hasAttribute('zen-essential') && !event.target.classList.contains("tab-icon-overlay")) {
+        gZenPinnedTabManager._onTabResetPinButton(event, this, 'reset');
       }
     }