title: CSS: what does a double-declaration do?
body: <p>i'm building a custom theme for wordpress and saw this in the default 2010 style.css file:</p>
  
  <pre><code>#wrapper {
    margin: 0 auto;
    width: 940px;
  }
  #wrapper {
    background: pink;
    margin-top: 20px;
    padding: 0 20px;
  }
  </code></pre>
  
  <p>now this is the default code (except the <code>pink</code>).  when i try and collapse it, which seems logical, it makes quite a difference.</p>
  
  <p>what i can't figure out is WHY you'd declare the same element twice like that?  i've never seen that before...</p>
  
  <p>WR!</p>