Improve sign up page on small screens

app/assets/stylesheets/about.scss

@@ -109,10 +109,18 @@
     }
   }
 
-  @media screen and (max-width: 360px) {
+  @media screen and (max-width: 625px) {
     .wrapper {
       padding: 20px;
     }
+
+    .screenshot-with-signup .mascot {
+      display: none;
+    }
+
+    .features-list {
+      display: block;
+    }
   }
 }