Fixed Split.js issues when resizing to around 1000px wide

src/web/stylesheets/layout/_structure.css

@@ -39,8 +39,8 @@ div#output {
 
 .split {
     box-sizing: border-box;
-    /* overflow: auto;
-    Removed to enable Background Magic button pulse to overflow.
+    /* overflow: auto; */
+    /* Removed to enable Background Magic button pulse to overflow.
     Replace this rule if it seems to be causing problems. */
     position: relative;
 }