diff --git a/src/ClaudeDo.Ui/Views/Controls/ModalShell.axaml.cs b/src/ClaudeDo.Ui/Views/Controls/ModalShell.axaml.cs
index 9ae35f36..19b17b2a 100644
--- a/src/ClaudeDo.Ui/Views/Controls/ModalShell.axaml.cs
+++ b/src/ClaudeDo.Ui/Views/Controls/ModalShell.axaml.cs
@@ -23,48 +23,57 @@ public class ModalShell : ContentControl
     public ICommand? CloseCommand { get => GetValue(CloseCommandProperty); set => SetValue(CloseCommandProperty, value); }
 
     private Window? _window;
-    private PixelPoint _dragStartScreen;
-    private PixelPoint _dragStartPos;
-    private bool _dragging;
 
     protected override void OnApplyTemplate(TemplateAppliedEventArgs e)
     {
         base.OnApplyTemplate(e);
         if (e.NameScope.Find<Border>("PART_TitleBar") is { } bar)
-        {
             bar.PointerPressed += OnTitleBarPressed;
-            bar.PointerMoved += OnTitleBarMoved;
-            bar.PointerReleased += OnTitleBarReleased;
-        }
     }
 
-    // VisualRoot is a TopLevelHost (not the Window) in Avalonia 12, so resolve the
-    // owning Window via TopLevel.GetTopLevel and drive the move manually — BeginMoveDrag
-    // and a VisualRoot-as-Window cast both fail here.
+    /// Mirrors what MainWindow does for itself: with an extended client area a maximised window
+    /// overhangs the screen by the invisible resize border, so the chrome has to be inset by
+    /// OffScreenMargin or its edges (and the close button) get clipped. Doing it here covers
+    /// every modal at once instead of per code-behind.
+    protected override void OnAttachedToVisualTree(VisualTreeAttachmentEventArgs e)
+    {
+        base.OnAttachedToVisualTree(e);
+        _window = TopLevel.GetTopLevel(this) as Window;
+        if (_window is null) return;
+        Margin = _window.OffScreenMargin;
+        _window.PropertyChanged += OnWindowPropertyChanged;
+    }
+
+    protected override void OnDetachedFromVisualTree(VisualTreeAttachmentEventArgs e)
+    {
+        base.OnDetachedFromVisualTree(e);
+        if (_window is not null) _window.PropertyChanged -= OnWindowPropertyChanged;
+        _window = null;
+    }
+
+    private void OnWindowPropertyChanged(object? sender, AvaloniaPropertyChangedEventArgs e)
+    {
+        if (e.Property == Window.OffScreenMarginProperty && _window is not null)
+            Margin = _window.OffScreenMargin;
+    }
+
+    /// <summary>
+    /// Hands the drag to the window manager instead of moving the window by hand.
+    /// </summary>
+    /// <remarks>
+    /// This is what makes Windows snap work — drag to the top edge to maximise, to a side for
+    /// half the screen, with the usual preview overlay. Assigning <c>Window.Position</c> per
+    /// pointer-move (what this used to do) bypasses the OS move loop entirely, so no snap
+    /// gesture is ever recognised. The OS only snaps resizable windows, so the non-resizable
+    /// modals opt out on their own without a flag here.
+    ///
+    /// Note: <c>VisualRoot</c> is a TopLevelHost rather than the Window in Avalonia 12, so the
+    /// window has to come from <see cref="TopLevel.GetTopLevel"/>. Do not capture the pointer —
+    /// <see cref="Window.BeginMoveDrag"/> runs its own modal loop and needs the input.
+    /// </remarks>
     private void OnTitleBarPressed(object? sender, PointerPressedEventArgs e)
     {
         if (!e.GetCurrentPoint(this).Properties.IsLeftButtonPressed) return;
-        _window = TopLevel.GetTopLevel(this) as Window;
-        if (_window is null) return;
-        _dragStartScreen = _window.PointToScreen(e.GetPosition(_window));
-        _dragStartPos = _window.Position;
-        _dragging = true;
-        e.Pointer.Capture(sender as IInputElement);
-    }
-
-    private void OnTitleBarMoved(object? sender, PointerEventArgs e)
-    {
-        if (!_dragging || _window is null
-            || !e.GetCurrentPoint(this).Properties.IsLeftButtonPressed) return;
-        var cur = _window.PointToScreen(e.GetPosition(_window));
-        _window.Position = new PixelPoint(
-            _dragStartPos.X + (cur.X - _dragStartScreen.X),
-            _dragStartPos.Y + (cur.Y - _dragStartScreen.Y));
-    }
-
-    private void OnTitleBarReleased(object? sender, PointerReleasedEventArgs e)
-    {
-        _dragging = false;
-        e.Pointer.Capture(null);
+        (TopLevel.GetTopLevel(this) as Window)?.BeginMoveDrag(e);
     }
 }