Fix GTK CSS warnings and popover cleanup on widget destroy

Remove overflow property from .icon-rounded (not valid in GTK CSS).
Remove prefers-reduced-motion media query (not supported by GTK CSS
engine - reduced motion is handled by gtk-enable-animations setting).
Unparent PopoverMenu on widget destroy to prevent finalization warnings
when library view refreshes.

data/resources/style.css

@@ -75,7 +75,6 @@ flowboxchild:focus-visible .card {
 /* Rounded icon clipping for list view */
 .icon-rounded {
     border-radius: 8px;
-    overflow: hidden;
 }
 
 /* ===== WCAG AAA Focus Indicators ===== */
@@ -190,14 +189,9 @@ row:focus-visible {
 }
 
 /* ===== Reduced Motion (WCAG AAA 2.3.3) ===== */
-@media (prefers-reduced-motion: reduce) {
-    * {
-        transition-duration: 0 !important;
-        transition-delay: 0 !important;
-        animation-duration: 0 !important;
-        animation-delay: 0 !important;
-    }
-}
+/* Note: GTK CSS does not support prefers-reduced-motion or !important.
+   Reduced motion is handled by the GTK toolkit settings instead
+   (gtk-enable-animations). */
 
 /* ===== Minimum Target Size (WCAG 2.5.8) ===== */
 button.flat.circular,

src/ui/library_view.rs

@@ -607,6 +607,12 @@ fn attach_context_menu(widget: &impl gtk::prelude::IsA<gtk::Widget>, menu_model:
     popover.set_parent(widget.as_ref());
     popover.set_has_arrow(false);
 
+    // Unparent the popover when the widget is destroyed to avoid GTK warnings
+    let popover_cleanup = popover.clone();
+    widget.as_ref().connect_destroy(move |_| {
+        popover_cleanup.unparent();
+    });
+
     // Right-click
     let click = gtk::GestureClick::new();
     click.set_button(3);