Merge branch '32700-extra-nav-border' into 'master'

Only show extra nav border on layout nav

Closes #32700

See merge request !11657

app/assets/stylesheets/framework/header.scss

@@ -40,7 +40,17 @@ header {
     }
 
     &.with-horizontal-nav {
-      border-color: transparent;
+      border-bottom: 0;
+
+      .navbar-border {
+        height: 1px;
+        position: absolute;
+        right: 0;
+        left: 0;
+        bottom: -1px;
+        background-color: $border-color;
+        opacity: 0;
+      }
     }
 
     .container-fluid {
@@ -114,16 +124,6 @@ header {
     }
   }
 
-  .navbar-border {
-    height: 1px;
-    position: absolute;
-    right: 0;
-    left: 0;
-    bottom: 0;
-    background-color: $border-color;
-    opacity: 0;
-  }
-
   .global-dropdown {
     position: absolute;
     left: -10px;