diff --git a/ui/flutter/AGENTS.md b/ui/flutter/AGENTS.md
index f827385c6..e20be7734 100644
--- a/ui/flutter/AGENTS.md
+++ b/ui/flutter/AGENTS.md
@@ -126,7 +126,7 @@ Guidelines:
 Use the following desktop reference metrics unless a specific screen requires a documented exception:
 
 - Reference window: `1024 x 768`
-- Primary rail width: `64px`
+- Primary rail width: `78px` (reserves space for native macOS traffic lights)
 - Secondary filter sidebar width: `256px`
 - Main content header height: `80px`
 - Window drag header height on Windows: `30px`
diff --git a/ui/flutter/lib/features/extensions/presentation/pages/extensions_page.dart b/ui/flutter/lib/features/extensions/presentation/pages/extensions_page.dart
index 9d7206056..043952ce4 100644
--- a/ui/flutter/lib/features/extensions/presentation/pages/extensions_page.dart
+++ b/ui/flutter/lib/features/extensions/presentation/pages/extensions_page.dart
@@ -30,7 +30,8 @@ import '../widgets/extension_setting_field.dart';
 import '../widgets/extension_update_dialog.dart';
 import '../widgets/extension_update_status.dart';
 
-const _extensionCardMinWidth = 290.0;
+// Keep three columns in the 1024px reference window with the wider primary rail.
+const _extensionCardMinWidth = 280.0;
 const _extensionGridSpacing = 10.0;
 
 int _extensionGridColumnCount(double width) {
diff --git a/ui/flutter/lib/features/settings/presentation/pages/settings_page.dart b/ui/flutter/lib/features/settings/presentation/pages/settings_page.dart
index c78a18a1b..eb1059594 100644
--- a/ui/flutter/lib/features/settings/presentation/pages/settings_page.dart
+++ b/ui/flutter/lib/features/settings/presentation/pages/settings_page.dart
@@ -2128,7 +2128,7 @@ class _BrowserExtensionLinks extends StatelessWidget {
               children: [
                 const Icon(Icons.open_in_new, size: 15),
                 const SizedBox(width: AppDesignTokens.space8),
-                Text(link.label),
+                Flexible(child: Text(link.label, maxLines: 1, overflow: TextOverflow.ellipsis)),
               ],
             ),
           ),
diff --git a/ui/flutter/lib/shared/theme/app_design_tokens.dart b/ui/flutter/lib/shared/theme/app_design_tokens.dart
index 615fb139e..4904b483f 100644
--- a/ui/flutter/lib/shared/theme/app_design_tokens.dart
+++ b/ui/flutter/lib/shared/theme/app_design_tokens.dart
@@ -5,7 +5,8 @@ class AppDesignTokens {
 
   static const double windowHeaderHeight = 30;
   static const double windowRadius = 12;
-  static const double railWidth = 68;
+  // Leave room for native macOS traffic lights while keeping rail widths consistent across platforms.
+  static const double railWidth = 78;
   static const double filterSidebarWidth = 192;
   static const double contentHeaderHeight = 48;
   static const double taskRowHeight = 72;
diff --git a/ui/flutter/test/widget_test.dart b/ui/flutter/test/widget_test.dart
index 2d7ae42ff..393b7b0bf 100644
--- a/ui/flutter/test/widget_test.dart
+++ b/ui/flutter/test/widget_test.dart
@@ -630,9 +630,9 @@ void main() {
     tester.view.physicalSize = const Size(1024, 768);
     await tester.pumpAndSettle();
     expect(gridColumns(), 3);
-    expect(tester.getSize(find.byKey(const ValueKey('extension-card-extension-0'))).width, greaterThanOrEqualTo(290));
+    expect(tester.getSize(find.byKey(const ValueKey('extension-card-extension-0'))).width, greaterThanOrEqualTo(280));
 
-    tester.view.physicalSize = const Size(1028, 608);
+    tester.view.physicalSize = const Size(1024, 608);
     await tester.pumpAndSettle();
     expect(gridColumns(), 3);
     expect(tester.getSize(find.byKey(const ValueKey('extension-search-field-container'))).width, 240);
@@ -644,6 +644,7 @@ void main() {
     tester.view.physicalSize = const Size(720, 608);
     await tester.pumpAndSettle();
     expect(find.byType(PrimaryRail), findsOneWidget);
+    expect(gridColumns(), 2);
     final compactSearchRect = tester.getRect(find.byKey(const ValueKey('extension-search-field-container')));
     expect(compactSearchRect.width, lessThan(240));
     expect(compactSearchRect.height, closeTo(sortRect.height, 0.01));
@@ -665,7 +666,7 @@ void main() {
   });
 
   testWidgets('extension cards compact large counts without crowding their actions', (WidgetTester tester) async {
-    await _setTestSize(tester, const Size(722, 608));
+    await _setTestSize(tester, const Size(720, 608));
     await tester.pumpWidget(
       ProviderScope(
         overrides: [extensionsControllerProvider.overrideWith(CrowdedExtensionCardController.new)],
@@ -683,7 +684,7 @@ void main() {
     final cardRect = tester.getRect(find.byKey(const ValueKey('extension-card-crowded-extension')));
     final statsRect = tester.getRect(find.byKey(const ValueKey('extension-card-stats-crowded-extension')));
     final actionsRect = tester.getRect(find.byKey(const ValueKey('extension-card-actions-crowded-extension')));
-    expect(cardRect.width, closeTo(290, 0.01));
+    expect(cardRect.width, closeTo(284, 0.01));
     expect(statsRect.right, lessThanOrEqualTo(actionsRect.left - 8));
     expect(actionsRect.right, lessThanOrEqualTo(cardRect.right - 14));
     expect(tester.takeException(), isNull);