title: CSS height 100% bug in firefox?
body: <p>I have the following html:</p>
  
  <pre><code>&lt;html&gt;
      &lt;head&gt; … &lt;/head&gt;
      &lt;body&gt;
          &lt;div id="entireContent"&gt;
              &lt;div class="header"&gt; … &lt;/div&gt;
              &lt;div id="contentBody"&gt; … &lt;/div&gt;
          &lt;/div&gt;
      &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>and the following css: </p>
  
  <pre><code>#entireContent {
      min-height: 100%;
      height: 100%;
      position: absolute;
      left: 0px;
      right: 0px;
      margin: auto;
      width: 1200px;
      max-width: 1200px;
      -moz-box-sizing: border-box;
  }
  
  .header {
      width: 100%;
      position: relative;
      margin: auto;
      height: 83px;
  }
  
  #contentBody {
      border-top: 5px solid rgb(45, 87, 40);
      height: calc(100% - 83px);
      -moz-box-sizing: border-box;
  }
  </code></pre>
  
  <p>In chrome everything it's ok. the contentBody stretches all over the remaining height.
  But in firefox add some white space (like 30px) down under the  tag..
  Does anyone know why? </p>