Hide the box

In the next commits we can pop it out, and display it there.

Author: vmcj

webapp/public/style_domjudge.css

@@ -764,4 +764,8 @@ blockquote {
 
 #no-picture-in-picture {
     display: none;
+}
+
+#pop-out-container {
+    display: none;
 }