Add arcade mode to chrome://dino

components/neterror/resources/neterror.css

 /* Copyright 2013 The Chromium Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file. */
 
 /* Don't use the main frame div when the error is in a subframe. */
 html[subframe] #main-frame-error {
   display: none;
 }
 
 /* Don't use the subframe error div when the error is in a main frame. */
@@ skipping 444 matching lines @@
 
   .interstitial-wrapper {
     margin-top: 5%;
   }
 
   .nav-wrapper {
     margin-top: 30px;
   }
 }
 
-@media (min-width: 600px) and (max-width: 736px) and (orientation: landscape) {
-  .offline .interstitial-wrapper {
-    margin-left: 0;
-    margin-right: 0;
-  }
-}
-
 @media (min-width: 420px) and (max-width: 736px) and
        (min-height: 240px) and (max-height: 420px) and
        (orientation:landscape) {
   .interstitial-wrapper {
     margin-bottom: 100px;
   }
 }
 
 @media (min-height: 240px) and (orientation: landscape) {
   .offline .interstitial-wrapper {
@@ skipping 25 matching lines @@
     overflow: inherit;
     padding: 0 8px;
   }
 }
 
 @media (max-width: 120px) {
   button {
     width: auto;
   }
 }
+
+.arcade-mode,
+.arcade-mode .runner-container,
+.arcade-mode .runner-canvas {
+  max-width: 100%;
+  overflow: hidden;
+}
+
+.arcade-mode #buttons,
+.arcade-mode #main-content {
+  opacity: 0;
+  overflow: hidden;
+}
+
+.arcade-mode .interstitial-wrapper {
+  height: 100vh;
+  max-width: 100%;
+  overflow: hidden;
+}
+
+.arcade-mode .runner-container {
+  left: 0;
+  margin: auto;
+  right: 0;
+  top: 0;
+  transform-origin: top center;
+  transition: transform 250ms cubic-bezier(0.4, 0.0, 1, 1) .4s;
+  z-index: 2;
+}