Center the detail tabs over the chat area

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/app/view.rs

@@ -325,10 +325,23 @@ impl App {
             .padding([0, 6])
             .on_press(Message::ToggleSidebar)
             .style(button::text);
+        // Center the tabs over the detail area, not the whole window, so the
+        // sidebar's width (plus its divider) shifts them along.
+        let detail_offset = if self.preferences.sidebar_collapsed {
+            0.0
+        } else {
+            self.preferences
+                .sidebar_width
+                .clamp(MIN_SIDEBAR_WIDTH, MAX_SIDEBAR_WIDTH) as f32
+                + 5.0
+        };
         stack![
-            container(self.detail_tabs())
+            row![
-                .center_x(Length::Fill)
+                Space::with_width(detail_offset),
-                .center_y(Length::Fill),
+                container(self.detail_tabs())
+                    .center_x(Length::Fill)
+                    .center_y(Length::Fill),
+            ],
             container(row![Space::with_width(TRAFFIC_LIGHT_WIDTH), toggle]).center_y(Length::Fill),
         ]
         .width(Length::Fill)