title: HTML/CSS: total page width is wider than content
body: <p>I have a strange problem, and I can't find the cause!  I have the following webpage:
    <a href="http://uk.translation-vocabulary.com/de-german" rel="noreferrer">http://uk.translation-vocabulary.com/de-german</a>
  and the perceived width of the page is perhaps 300px greater than the width of the content.  So a horizontal scrollbar is present even when the viewport is horizontally stretched to match the visible content.</p>
  
  <p>I have been inspecting elements with Firebug, trying to find the culprit.  No success so far.</p>
  
  <p>This effect observed in Firefox, Safari, Chrome.  Untested: IE.</p>
  
  <p>Any help greatly appreciated!</p>
  
  <p>Benjamin.</p>