title: What CSS is responsible for center aligning the div 'columns twelve' in this page
body: <p>If we look at the the page <a href="http://www.groupon.co.uk/deals/edinburgh/white-apple-2-6/55361548" rel="nofollow noreferrer">http://www.groupon.co.uk/deals/edinburgh/white-apple-2-6/55361548</a> there is a div element with CSS classes <code>columns</code> and <code>twelve</code>. It seems to me that this class is somehow responsible for a center aligned container - which has an equally spaced margin on the left and right. </p>
  
  <p><img src="https://i.stack.imgur.com/3tIaI.png" alt="enter image description here"></p>
  
  <p>I have tried studying the CSS on this page for quite some time to determine what piece of CSS is responsible for the center placing of the main content of the page but I cannot find what is giving this div the placement in the center.</p>
  
  <p>Can somebody please highlight for me the CSS assigned to columns twelve class on this page giving the center with white spacing on the left and right of the div? Thank you!</p>