fix: Cleaned up codeblock code + fixed up issue with bottom border

Author: lamATnginx

assets/css/v2/style.css

@@ -1050,13 +1050,9 @@ blockquote.side-callout {
 
 .tab-content {
   border-bottom: 1px solid black;
-  margin-left: calc(-1 * var(--overflow-gutter-extension));
 
   .tab-pane {
     display: none;
-
-    /* Push the content 1rem right due to the gutter displacement */
-    margin-left: 1rem;
   }
 
   .active {