title: CSS mystery: Width being set to 0px without any CSS rules?
body: <p>So, check out <a href="http://www.madingley.org/uploaded/devtools.png" rel="nofollow noreferrer">this screenshot of a page I'm working on in Chrome Developer Tools</a>:</p>
  <p><a href="https://i.stack.imgur.com/SB00j.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/SB00j.png" alt="" /></a></p>
  <p>The top rule in 'Matched CSS Rules' suggests that the width of the element should be 160px.</p>
  <p>But in 'Computed Style' the width is actually 0px.</p>
  <p>If you click on the '0px', it again shows the rule suggesting that the width should be 160px. But it's not.</p>
  <p>What's going on? What is setting the width to 0px that is invisble to Chrome Developer Tools?</p>
  <p>And how can I debug this?</p>