title: Unable to set the width of webkit-scrollbar-thumb
body: <p>I am trying to style up a custom scrollbar that works in Chrome and Safari. I’ve tried the following CSS:</p>
  
  <pre><code>::-webkit-scrollbar {
      width: 15px;
  }
  
  ::-webkit-scrollbar-track {
      background-color: rgba(100, 100, 100, .5);
      width: 15px;
  }
  
  ::-webkit-scrollbar-thumb {
      background-color: #818B99;
      border-radius: 9px;
      width: 9px;
  }
  </code></pre>
  
  <p>However the <code>width</code> on the <code>-webkit-scrollbar-thumb</code> is being ignored. I would like the thumb to be thinner than the track, as above.  </p>
  
  <p>It appears that I can fake the width by setting a border on the <code>-webkit-scrollbar-thumb</code> of 3px with the same colour as the track, however this only works with an opaque background colour, and I need it to work with a transparent colour for the track as above.</p>
  
  <p>Example jsfiddle: <a href="http://jsfiddle.net/L6Uzu/1/">http://jsfiddle.net/L6Uzu/1/</a></p>