diff --git a/l10n b/l10n
index 70534bcec..102a19cde 160000
--- a/l10n
+++ b/l10n
@@ -1 +1 @@
-Subproject commit 70534bcec754b1cd108f275708cfba4427d0b7d4
+Subproject commit 102a19cdee3cee5e6f963902f1546e61a0283954
diff --git a/src/browser/app/profile/features.inc b/src/browser/app/profile/features.inc
index cf2efc883..7835d02b6 100644
--- a/src/browser/app/profile/features.inc
+++ b/src/browser/app/profile/features.inc
@@ -28,7 +28,11 @@ pref('zen.injections.match-urls', 'http://localhost/*', locked);
 #endif
 pref('zen.rice.share.notice.accepted', false);
 
+#ifdef XP_MACOSX
+pref('zen.theme.border-radius', 10); // In pixels
+#else
 pref('zen.theme.border-radius', 8); // In pixels
+#endif
 
 pref('zen.theme.color-prefs.use-workspace-colors', true);
 
diff --git a/src/browser/components/sessionstore/SessionStore-sys-mjs.patch b/src/browser/components/sessionstore/SessionStore-sys-mjs.patch
index 1e49c4903..ebc9b26d2 100644
--- a/src/browser/components/sessionstore/SessionStore-sys-mjs.patch
+++ b/src/browser/components/sessionstore/SessionStore-sys-mjs.patch
@@ -1,5 +1,5 @@
 diff --git a/browser/components/sessionstore/SessionStore.sys.mjs b/browser/components/sessionstore/SessionStore.sys.mjs
-index 5633e5032f5d50c70512187d27e045b579978927..724fe7ec3bb6058c006f25b1d9ee0ce10f7b2e36 100644
+index 5633e5032f5d50c70512187d27e045b579978927..6b9e56cb62a4812925ff812763ea9b0e6a478202 100644
 --- a/browser/components/sessionstore/SessionStore.sys.mjs
 +++ b/browser/components/sessionstore/SessionStore.sys.mjs
 @@ -2081,7 +2081,6 @@ var SessionStoreInternal = {
@@ -41,6 +41,15 @@ index 5633e5032f5d50c70512187d27e045b579978927..724fe7ec3bb6058c006f25b1d9ee0ce1
  
        if (inBackground === false) {
          aWindow.gBrowser.selectedTab = newTab;
+@@ -5225,7 +5225,7 @@ var SessionStoreInternal = {
+     }
+ 
+     let workspaceID = aWindow.getWorkspaceID();
+-    if (workspaceID) {
++    if (workspaceID && !(this.isLastRestorableWindow() && AppConstants.platform == "macosx")) {
+       winData.workspaceID = workspaceID;
+     }
+   },
 @@ -5416,14 +5416,15 @@ var SessionStoreInternal = {
      }
  
diff --git a/src/zen/common/ZenUIManager.mjs b/src/zen/common/ZenUIManager.mjs
index f7120a121..71e6f350c 100644
--- a/src/zen/common/ZenUIManager.mjs
+++ b/src/zen/common/ZenUIManager.mjs
@@ -382,6 +382,12 @@ var gZenUIManager = {
 
   // Section: Notification messages
   _createToastElement(messageId, options) {
+    // Check if this message ID already exists
+    for (const child of this._toastContainer.children) {
+      if (child._messageId === messageId) {
+        return [child, true];
+      }
+    }
     const element = document.createXULElement('vbox');
     const label = document.createXULElement('label');
     document.l10n.setAttributes(label, messageId, options);
@@ -393,23 +399,34 @@ var gZenUIManager = {
       element.appendChild(description);
     }
     element.classList.add('zen-toast');
-    return element;
+    element._messageId = messageId;
+    return [element, false];
   },
 
   async showToast(messageId, options = {}) {
-    const toast = this._createToastElement(messageId, options);
+    const [toast, reused] = this._createToastElement(messageId, options);
     this._toastContainer.removeAttribute('hidden');
     this._toastContainer.appendChild(toast);
-    await this.motion.animate(toast, { opacity: [0, 1], scale: [0.8, 1] }, { type: 'spring', bounce: 0.5, duration: 0.7 });
-    await new Promise((resolve) => setTimeout(resolve, 3000));
-    await this.motion.animate(toast, { opacity: [1, 0], scale: [1, 0.9] }, { duration: 0.2, bounce: 0 });
-    const toastHeight = toast.getBoundingClientRect().height;
-    // 5 for the separation between toasts
-    await this.motion.animate(toast, { marginBottom: [0, `-${toastHeight + 5}px`] }, { duration: 0.2 });
-    toast.remove();
-    if (!this._toastContainer.hasChildNodes()) {
-      this._toastContainer.setAttribute('hidden', 'true');
+    if (reused) {
+      await this.motion.animate(toast, { scale: 0.2 }, { duration: 0.1, bounce: 0 });
+      toast._useCount++;
+    } else {
+      toast._useCount = 1;
     }
+    if (!toast.style.hasOwnProperty('transform')) {
+      toast.style.transform = 'scale(0)';
+    }
+    await this.motion.animate(toast, { scale: 1 }, { type: 'spring', bounce: 0.2, duration: 0.5 });
+    await new Promise((resolve) => setTimeout(resolve, 3000));
+    if (toast._useCount <= 1) {
+      await this.motion.animate(toast, { opacity: [1, 0], scale: [1, 0.5] }, { duration: 0.2, bounce: 0 });
+      toast.remove();
+      if (!this._toastContainer.hasChildNodes()) {
+        this._toastContainer.setAttribute('hidden', 'true');
+      }
+      return;
+    }
+    toast._useCount--;
   },
 
   get panelUIPosition() {
diff --git a/src/zen/common/styles/zen-popup.css b/src/zen/common/styles/zen-popup.css
index e91498b9b..e5ea9309c 100644
--- a/src/zen/common/styles/zen-popup.css
+++ b/src/zen/common/styles/zen-popup.css
@@ -338,7 +338,6 @@ menuitem {
   position: fixed;
   top: calc(var(--zen-element-separation) * 2);
   z-index: 1000;
-  gap: 1rem;
   display: flex;
   align-items: end;
 
@@ -351,7 +350,7 @@ menuitem {
   }
 
   & .zen-toast {
-    padding: 0.5rem 0.6rem;
+    padding: 10px;
     border-radius: 12px;
     background: linear-gradient(
       170deg,
@@ -362,14 +361,16 @@ menuitem {
     box-shadow: 0 0 14px 3px rgba(0, 0, 0, 0.05);
     border: 1px solid rgba(0, 0, 0, 0.1);
     display: flex;
-    font-weight: 500;
-    gap: 5px;
+    font-weight: 600;
     flex-direction: column;
-    gap: 2px;
-    width: fit-content;
+    width: max-content;
+    font-size: medium;
+    position: absolute;
+    transform-origin: top center;
 
     & .description {
       opacity: 0.6;
+      font-size: small;
     }
   }
 }
diff --git a/src/zen/compact-mode/ZenCompactMode.mjs b/src/zen/compact-mode/ZenCompactMode.mjs
index b69d1a362..c5bf01fca 100644
--- a/src/zen/compact-mode/ZenCompactMode.mjs
+++ b/src/zen/compact-mode/ZenCompactMode.mjs
@@ -48,6 +48,7 @@ var gZenCompactModeManager = {
 
     // Clear hover states when window state changes (minimize, maximize, etc.)
     window.addEventListener('sizemodechange', () => this._clearAllHoverStates());
+    window.addEventListener('TabOpen', this._onTabOpen.bind(this));
 
     if (AppConstants.platform == 'macosx') {
       window.addEventListener('mouseover', (event) => {
@@ -194,11 +195,7 @@ var gZenCompactModeManager = {
       const isCompactMode = this.preference;
       const canHideSidebar =
         Services.prefs.getBoolPref('zen.view.compact.hide-tabbar') || gZenVerticalTabsManager._hasSetSingleToolbar;
-      let canAnimate =
-        lazyCompactMode.COMPACT_MODE_CAN_ANIMATE_SIDEBAR &&
-        !this.sidebar.hasAttribute('zen-user-show') &&
-        !this.sidebar.hasAttribute('zen-has-empty-tab') &&
-        !this.sidebar.hasAttribute('zen-has-hover');
+      let canAnimate = lazyCompactMode.COMPACT_MODE_CAN_ANIMATE_SIDEBAR && !this.isSidebarPotentiallyOpen();
       if (typeof this._wasInCompactMode !== 'undefined') {
         canAnimate = false;
         delete this._wasInCompactMode;
@@ -552,6 +549,21 @@ var gZenCompactModeManager = {
       }
     }
   },
+
+  isSidebarPotentiallyOpen() {
+    return (
+      this.sidebar.hasAttribute('zen-user-show') ||
+      this.sidebar.hasAttribute('zen-has-hover') ||
+      this.sidebar.hasAttribute('zen-has-empty-tab')
+    );
+  },
+
+  _onTabOpen(event) {
+    const tab = event.target;
+    if (!tab.selected && this.preference && !this.isSidebarPotentiallyOpen()) {
+      gZenUIManager.showToast('zen-background-tab-opened');
+    }
+  },
 };
 
 document.addEventListener(