non native menu fixs (thanks i486)

Author: K4sum1

browser/themes/shared/customizableui/panelUI-shared.css

@@ -2198,3 +2198,33 @@ panelview {
   padding: var(--space-xxlarge) 0 var(--space-medium);
   gap: var(--space-small);
 }
+
+@media (-moz-bool-pref: "widget.non-native-theme.enabled") {
+  #PlacesToolbarItems toolbarbutton.bookmark-item menupopup.toolbar-menupopup menuseparator::before {
+    border-top: 1px solid var(--panel-separator-color) !important;
+    content: "" !important;
+    display: block !important;
+    flex: 1 !important;
+  }
+
+  #PlacesToolbarItems toolbarbutton.bookmark-item menupopup.toolbar-menupopup menuseparator {
+    appearance: unset !important;
+    -moz-default-appearance: unset !important;
+    border-top: unset !important;
+    border-bottom: unset !important;
+  }
+
+  #bookmarks-menu-button menupopup#BMB_bookmarksPopup menuseparator::before {
+    border-top: 1px solid var(--panel-separator-color) !important;
+    content: "" !important;
+    display: block !important;
+    flex: 1 !important;
+  }
+
+  #bookmarks-menu-button menupopup#BMB_bookmarksPopup menuseparator {
+    appearance: unset !important;
+    -moz-default-appearance: unset !important;
+    border-top: unset !important;
+    border-bottom: unset !important;
+  }
+}