title: CSS "top" property not working with percentage (%), but working with pixels (px)
body: <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-css lang-css prettyprint-override"><code>body {
    background: #8E2800;
  }
  #main {
    background: purple;
    position: relative;
    color: white;
  }
  #title {
    background: grey;
    position: absolute;
    top: 50%;
    left: 50%;
    height: 40%;
    width: 50%;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;div&gt;
    &lt;div id="main"&gt;
      &lt;div id="title"&gt;
        &lt;h2&gt;Weather Forecast&lt;/h2&gt;
      &lt;/div&gt;
    &lt;/div&gt;
  &lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>
  
  <p>Also as working demo can be found on codepen:
  <a href="http://codepen.io/manzur/pen/RomyjK?editors=1100" rel="nofollow noreferrer">http://codepen.io/manzur/pen/RomyjK?editors=1100</a></p>