title: div doesn't fully expand to content
body: <p>I'm not a css expert but I'm running out of ideas what could trigger this unwanted behaviour. I'm want to use a <code>div</code> as background for the main section of my site. Once there is a lot of content in my <code>div content</code> the <code>div content_wrapper</code> doesn't fully expand. This a section of my HTML</p>
  
  <pre><code>&lt;div class="content_wrapper"&gt;
      &lt;div class="content"&gt;
          &lt;h1&gt;Some heading&lt;/h1&gt;
          &lt;p&gt;lot's of text&lt;/p&gt;
      &lt;/div&gt;
  &lt;footer&gt;
      &lt;div id="foot"&gt;
          &lt;a id="disclaimer" href="disclaimer.html"&gt; disclaimer&lt;/a&gt; 
      &lt;/div&gt;
      &lt;/footer&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>And the .css. </p>
  
  <pre><code>.content_wrapper{
      position: absolute;
      width: 100%;
      height: 100%;
      top: 215px;
      background-color: #EEE;
  
  }
  .content{
      z-index: 5;
      float:left;
      margin: 50px 0 50px 20px;
      width: 75%;
      padding: 20px;
      background-color: #FFF;
      border-left: dashed 1px #CCC;
      border-top: dashed 1px #CCC;
  
      -webkit-border-top-left-radius: 25px;
      -moz-border-radius-topleft: 25px;
      border-top-left-radius: 25px;
  }
  </code></pre>
  
  <p>Any ideas what is going on and why?</p>