title: Three equal-width columns with margin
body: <p>I'm trying to create a layout where I have three equal-wdith columns (33% width each). However, I want a 15px margin on either side of the middle column.</p>
  
  <p>Please see this jsbin example I've created: <a href="http://jsbin.com/usiduy/edit" rel="nofollow">http://jsbin.com/usiduy/edit</a><br>
  How can I get the blue column to sit on the right?</p>