title: :before && :after pseudo elements not showing Firefox
body: <p>Firefox is not displaying :after and :before but they do show in Chrome.</p>
  
  <p>Firefox &amp; Chrome:
  <a href="https://i.stack.imgur.com/9cBr5.png" rel="noreferrer"><img src="https://i.stack.imgur.com/9cBr5.png" alt="enter image description here"></a></p>
  
  <p>Viewing the source directly in Firefox shows the CSS is there:
  <a href="https://i.stack.imgur.com/0QBgc.png" rel="noreferrer"><img src="https://i.stack.imgur.com/0QBgc.png" alt="enter image description here"></a></p>
  
  <p>This is happening on multiple elements on the page using :after.</p>
  
  <p>I have tried using both before and after. I have also tried both :: and : variations.</p>
  
  <p>If I use the same CSS in codepen it works:
  <a href="http://codepen.io/anon/pen/XXOZWL" rel="noreferrer">http://codepen.io/anon/pen/XXOZWL</a></p>
  
  <pre><code>&lt;input type="checkbox" class="mobile_auth" /&gt;
  
  .mobile_auth {
      visibility: hidden;
  }
  
  .mobile_auth:after {
      background-image: url('https://lh4.googleusercontent.com/-gD_ItALdha8/AAAAAAAAAAI/AAAAAAAAAB4/eEbUyChzCJc/photo.jpg?sz=110');
      content: '';
      height: 33px;
      width: 33px;
      display: block;
      cursor: pointer;
      visibility: visible;
      margin: auto;
      position: relative;
      top: -3px;
      left: 3px;
  }
  
  .mobile_auth::after {
      background-image: url('https://lh4.googleusercontent.com/-gD_ItALdha8/AAAAAAAAAAI/AAAAAAAAAB4/eEbUyChzCJc/photo.jpg?sz=110');
      content: '';
      height: 33px;
      width: 33px;
      display: block;
      cursor: pointer;
      visibility: visible;
      margin: auto;
      position: relative;
      top: -3px;
      left: 3px;
  }
  
  .mobile_auth:checked:after {
      background-position: right;
  }
  </code></pre>
  
  <p>You can see the page live at: ***.com login with User: demo Pass: demo and click 'config'. Lots of buttons are missing in the latest Firefox.</p>
  
  <p>It's strange because it doesn't show at all. It's not like the element is there and I can't see it. It isn't even showing that it exists in console.</p>