diff --git a/lib/widgets/assistant_artifact_sidebar.dart b/lib/widgets/assistant_artifact_sidebar.dart
index 308c5b16..19b6d220 100644
--- a/lib/widgets/assistant_artifact_sidebar.dart
+++ b/lib/widgets/assistant_artifact_sidebar.dart
@@ -401,6 +401,10 @@ class _AssistantArtifactSidebarState extends State<AssistantArtifactSidebar> {
 class AssistantArtifactSidebarRevealButton extends StatelessWidget {
   const AssistantArtifactSidebarRevealButton({super.key, required this.onTap});
 
+  static const double _buttonWidth = 32;
+  static const double _buttonHeight = 36;
+  static const double _buttonRadius = 8;
+
   final VoidCallback onTap;
 
   @override
@@ -411,10 +415,10 @@ class AssistantArtifactSidebarRevealButton extends StatelessWidget {
       child: InkWell(
         key: const Key('assistant-artifact-pane-toggle'),
         onTap: onTap,
-        borderRadius: BorderRadius.circular(AppRadius.sidebar),
+        borderRadius: BorderRadius.circular(_buttonRadius),
         child: Container(
-          width: 44,
-          height: 56,
+          width: _buttonWidth,
+          height: _buttonHeight,
           decoration: BoxDecoration(
             gradient: LinearGradient(
               begin: Alignment.topLeft,
@@ -424,7 +428,7 @@ class AssistantArtifactSidebarRevealButton extends StatelessWidget {
                 palette.chromeSurface,
               ],
             ),
-            borderRadius: BorderRadius.circular(AppRadius.sidebar),
+            borderRadius: BorderRadius.circular(_buttonRadius),
             border: Border.all(
               color: palette.chromeStroke.withValues(alpha: 0.88),
               width: 0.9,
diff --git a/test/features/assistant_page_suite.dart b/test/features/assistant_page_suite.dart
index 53b9cbf5..4d07268e 100644
--- a/test/features/assistant_page_suite.dart
+++ b/test/features/assistant_page_suite.dart
@@ -296,6 +296,34 @@ void main() {
     },
   );
 
+  testWidgets('AssistantPage uses a compact collapsed artifact toggle', (
+    WidgetTester tester,
+  ) async {
+    final controller = await createTestController(tester);
+
+    await pumpPage(
+      tester,
+      child: AssistantPage(controller: controller, onOpenDetail: (_) {}),
+      platform: TargetPlatform.macOS,
+    );
+
+    final toggle = find.byKey(const Key('assistant-artifact-pane-toggle'));
+    final decoratedBody = find.descendant(
+      of: toggle,
+      matching: find.byWidgetPredicate(
+        (widget) => widget is Container && widget.decoration is BoxDecoration,
+      ),
+    );
+
+    expect(toggle, findsOneWidget);
+    expect(tester.getSize(toggle), const Size(32, 36));
+
+    final body = tester.widget<Container>(decoratedBody);
+    final decoration = body.decoration! as BoxDecoration;
+
+    expect(decoration.borderRadius, BorderRadius.circular(8));
+  });
+
   testWidgets(
     'AssistantPage shows Single Agent provider selector on the right',
     (WidgetTester tester) async {},