Make the submission thank you page vertically

centered

app/assets/stylesheets/application.css.scss

@@ -35,6 +35,10 @@ $light: #fff;
   height: 100%;
 }
 
+.is-vcentered{
+  height: 100vh;
+}
+
 .content {
   padding: 30px 60px 50px;