Firefox flex height fix

whats_open/templates/404.html

@@ -7,13 +7,13 @@
       display: -ms-flexbox;
       display: -webkit-flex;
       display: flex;
+      height: 100%;
     }
     .container {
       margin: auto;
     }
     h1 {
       font-family: "Helvetica Neue", "Helvetica", sans-serif;
-      margin-top:	-8%;
     }
     #squirrels {
       width: 100%;