title: why use negative margins?
body: <p>Just looking at some CSS here, and I noticed:</p>
  
  <pre><code>.head{position:relative;overflow:hidden;margin:-30px 0 0 -25px;width:820px;padding:20px 25px 0 25px;background:url(/images/bkg.gif) 0 0 no-repeat;}
  </code></pre>
  
  <p>Why would you put -30 and -25px margins?</p>