make blacked out spans have a grey background when hovering so it is more clear what state they are in

templates/index.tmpl

@@ -64,6 +64,10 @@
       background-color: white;
     }
 
+    #paper span.black:hover {
+      background-color: grey;
+    }
+
     #aboutToggle {
       color: white;
       font-weight: bold;