diff --git a/browser/themes/windows/browser.css b/browser/themes/windows/browser.css
index 7dcb386d38d25ee483f19322ea327b4dc6a244e0..c30a16e503224691572118efa0f1ff9e108895b3 100644
--- a/browser/themes/windows/browser.css
+++ b/browser/themes/windows/browser.css
@@ -41,7 +41,6 @@
     @media -moz-pref("widget.windows.mica.toplevel-backdrop", 2) {
       /* For acrylic, do the same we do for popups to guarantee some contrast */
       /* stylelint-disable-next-line stylelint-plugin-mozilla/use-design-tokens, stylelint-plugin-mozilla/no-base-design-tokens */
-      background-color: light-dark(var(--color-white-alpha-60), var(--color-black-alpha-60));
     }
 
     /* Using a semitransparent background preserves the tinting from the backdrop.
@@ -73,14 +72,13 @@
 }
 
 /* This is needed for Windows 10, see bug 1961257 */
-@media (-moz-windows-accent-color-in-titlebar) {
-  :root[customtitlebar][sizemode="normal"] #navigator-toolbox {
+  :root[customtitlebar][sizemode="normal"] #browser {
+    --zen-sidebar-compact-top-offset: 1px;
     border-top: 0.5px solid ActiveBorder;
     &:-moz-window-inactive {
       border-top-color: InactiveBorder;
     }
   }
-}
 
 /* Titlebar */
 
