undisplay container-overview till width of 970px

static/css/application.css

@@ -407,6 +407,12 @@ div#opacity-buttons {
     }
 }
 
+@media (max-width: 970px) {
+    div#container-overview {
+        display: none;
+    }
+}
+
 @media (min-width: 1850px) {
     div#axis-container {
         width: 40%;