title: How to center the Firefox #urlbar?
body: <p>In the Firefox navigationbar I only have the back/forward buttons on the one side<br>
  and the menu button on the other side of the urlbar.<br>
  Now I'd like to horizontally center the urlbar on the remaining space of the navigationbar with a custom userstyle.</p>
  
  <p>In my css, I've added the following code:</p>
  
  <pre><code>#urlbar {
   width: 800px;
   margin: 0 auto !important;
  }
  </code></pre>
  
  <p>But that doesn't work. Can you maybe point me in the right direction?  </p>
  
  <p>Thanks!</p>