tweaked fix of 3rd level margin issue for screen width less than 991px

css/oeru_course_core_alter.css

@@ -701,6 +701,6 @@ a.external {
 }
 
 /* fix bug with 3rd level navigation having a 15px inset from the rest of the margin at small screen widths */
-#primary .third-level-nav .col-md-12 {
-    padding-right: 0 !important;
+@media (max-width: 991px) {
+    #primary .third-level-nav .col-md-12 { padding-right: 0 !important; }
 }