title: Firefox gradient not working
body: <p>I created small web page:</p>
  
  <pre><code>&lt;!DOCTYPE html&gt;
  &lt;html&gt;
    &lt;head&gt;
      &lt;style&gt;
         html
         {
          position: fixed; 
         }
         body {
         background: radial-gradient(ellipse at center, rgba(141,141,141,0) 0,rgba(141,141,141,1) 100%);
         }
  
      &lt;/style&gt;
    &lt;/head&gt;
    &lt;body&gt;
      &lt;p&gt;TEST&lt;/p&gt;
    &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>It's small example to illustrate problem but I have bigger application where is the same. When I add position: fixed to html tag gradient on body tag stops working. It works fine on Google Chrome, Internet Explorer, Microsoft Edge but not on Firefox. I can add that when a change gradient to background-color or backgorund-image it works fine. Firefox version:53.0.3. Do you have any ideas how to deal with that? </p>