title: CSS div cut off screen by margin-left - need scrollbar
body: <p>I have a div that has <code>top:50%; left:50%;</code> and also has a margin-left of some value (usually negative).</p>
  
  <p>When the browser window is re-sized, the edge of the div can get cut off. Is there any easy way to easily add in a scrollbar when this happens?</p>
  
  <p><a href="http://jsfiddle.net/t3sqeceL/1/" rel="nofollow">DEMO</a></p>