fix(nav): zero FA vertical-align in top bar for flex centering

assets/css/frontend/nav/zib-utilities.css

@@ -331,13 +331,13 @@ body.mobile-navbar-show { overflow: hidden; }
   display: inline-block;
   vertical-align: middle;
 }
-/* FA in header: kill common FA vertical drift vs flex centers */
+/* FA in header: line-height only — do NOT set vertical-align (causes flex drift). */
 .navbar-top .fa,
 .navbar-top .fas,
 .navbar-top .far,
 .navbar-top .fab {
-  line-height: 1;
-  vertical-align: -0.05em;
+  line-height: 1 !important;
+  vertical-align: 0 !important;
 }
 .navbar-top .css-icon {
   width: 1em;