Fix color

Author: bcbogdan

src/theme/DocSidebar/Mobile/index.scss

@@ -13,7 +13,7 @@
 
   &__additional-links {
     flex-shrink: 0;
-    background: var(--ifm-background-color);
+    background: var(--color-background);
     border-top: 1px solid var(--ifm-toc-border-color);
     padding: 0.75rem 0;
     margin-top: 0;