handle fullscreen mode better

chrome/hide_tabs_with_one_tab.css

@@ -4,6 +4,7 @@ See the above repository for updates as well as full license text. */
 /* Makes tabs toolbar items zero-height initially and sets enlarge them to fill up space equal to tab-min-height set on tabs. Optionally use privatemode_indicator_as_menu_button.css to replace main menu icon with private browsing indicator while tabs are hidden. */
 /* Firefox 65+ only */
 
+
 :root[sizemode="normal"] #nav-bar{ --uc-window-drag-space-width: 20px }
 
 #titlebar{ -moz-appearance: none !important; }
@@ -53,6 +54,6 @@ See the above repository for updates as well as full license text. */
 :root[tabsintitlebar] #toolbar-menubar[autohide="true"][inactive]{
   transition: height 0ms steps(1) 80ms;
 }
-#nav-bar{
+:where(#nav-bar){
   border-inline: var(--uc-window-drag-space-width) solid var(--toolbar-bgcolor);
 }