fix: mobile menu wrong height caused by new stacking context from backdrop-blur

assets/css/main.css

@@ -451,7 +451,7 @@ pre {
 }
 
 /* Prevent body scroll when mobile menu is open */
-body:has(#mobile-menu-toggle:checked) {
+body:has(#mobile-menu-toggle:checked):not(:has(#mobile-menu-dialog.mobile-menu-style-dropdown)) {
   overflow: hidden;
 }
 
@@ -485,15 +485,6 @@ body:has(#mobile-menu-toggle:checked) {
     opacity 0.3s ease-in-out;
 }
 
-/* A backdrop-filter turns the header pill into a containing block for
-   position:fixed descendants, which would trap the fullscreen mobile menu
-   inside it. Lift the filter while that menu is open — the fullscreen
-   overlay covers the header anyway, so the change is invisible. */
-header > div:has(.mobile-menu-fullscreen #mobile-menu-toggle:checked) {
-  -webkit-backdrop-filter: none;
-  backdrop-filter: none;
-}
-
 /* Dropdowns near the end of the bar open leftward so they stay on screen */
 .nested-menu:nth-last-child(-n + 3) .menuhide,
 .mobile-header-row .menuhide {