title: micro clearfix doesn't work
body: <p>i am using nicolas gallagher's micro-clearfix in my Fixed layout. And in my layout the green colored footer does not appear. Which means the clearfix doesn't work properly </p>
  
  <pre><code>&lt;div class="container"&gt;
      &lt;aside class="al"&gt;
      &lt;/aside&gt;
      &lt;section class="content"&gt;
  
      &lt;/section&gt;
      &lt;aside class="ar"&gt;
      &lt;/aside&gt;
      &lt;footer class="cf"&gt;
      &lt;/footer&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>css</p>
  
  <pre><code>.container {
      width: 500px;
      height: 400px;
      margin: 0 auto;
  }
  .al {
      background: red;
      width: 100px;
      height: 100px;
      float: left;
  }
  .content {
      float: left;
      width: 300px;
      height: 100px;
      background: black;
  }
  .ar {
      background: red;
      width: 100px;
      height: 100px;
      float: left;
  }
  footer {
      background: blue;
      width: 100%;
      height: 100px;
      background: green;
  }
  </code></pre>
  
  <p>and micro clearfix</p>
  
  <pre><code>.cf:after, .cf:before {
      content: " ";
      display: table; 
  }
  .cf:after {
      clear: both;
  }
  .cf {
      *zoom: 1;
  }
  </code></pre>
  
  <p><a href="http://jsfiddle.net/4NJ6v/1/" rel="nofollow">DEMO</a></p>
  
  <p>What am i doing wrong. how do i make this work. could someone help me please</p>