Update wavgen.css

wavgen.css

@@ -121,7 +121,7 @@ img:hover {opacity: 0.7;}
 .modal {
   display: none; /* Hidden by default */
   position: fixed; /* Stay in place */
-  z-index: 1; /* Sit on top */
+  z-index: 500; /* Sit on top */
   padding-top: 100px; /* Location of the box */
   left: 0;
   top: 0;