diff --git a/static/css/theme.css b/static/css/theme.css
index 0f8c6e0d11..e09fc349e1 100644
--- a/static/css/theme.css
+++ b/static/css/theme.css
@@ -1026,11 +1026,7 @@ tbody > tr:nth-child(even) > td {
 .topbar-sidebar-divider::after {
     content: "\00a0";
 }
-@media screen and (max-width: 48rem) {
-    .topbar-sidebar-divider {
-        border-inline-start-color: transparent;
-    }
-}
+
 .topbar-wrapper > .topbar-area-start {
     display: flex;
     flex-direction: row;
diff --git a/static/css/variant.css b/static/css/variant.css
index 59947c6d7a..12c619af81 100644
--- a/static/css/variant.css
+++ b/static/css/variant.css
@@ -256,6 +256,11 @@ table {
 .topbar-sidebar-divider {
     border-inline-start-color: var(--INTERNAL-MENU-TOPBAR-SEPARATOR-color);
 }
+@media screen and (max-width: 48rem) {
+    .topbar-sidebar-divider {
+        border-inline-start-color: transparent;
+    }
+}
 
 #R-body a[aria-disabled="true"],
 #R-searchresults .autocomplete-suggestion > .context {
@@ -462,6 +467,11 @@ article ul > li > input[type="checkbox"] {
 #R-header-topbar {
     border-inline-end-color: var(--INTERNAL-MENU-TOPBAR-BORDER-color);
 }
+@media screen and (max-width: 48rem) {
+    .mobile-support #R-header-topbar {
+        border-inline-end-color: var(--INTERNAL-MENU-BORDER-color);
+    }
+}
 
 #R-header-wrapper,
 #R-homelinks,