title: Vertical align responsive container in Bootstrap
body: <p>I'm trying to vertical align a container div within a jumbotron. </p>
  
  <p>Because the height of the container (and so the jumbotron also) is variable <code>top: 50%; margin-top: -'height * 0.5'</code> won't work.</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false">
  <div class="snippet-code">
  <pre class="snippet-code-css lang-css prettyprint-override"><code>@import url('https://maxcdn.bootstrapcdn.com/bootstrap/3.3.2/css/bootstrap.min.css');
   .banner {
    padding: 48px 0px 48px 0px;
    text-align: center;
  }
  .banner:after {
    content: "";
    display: block;
    padding-top: 12.5%;
  }
  
    .container {
    background: red !important; /* For testing vertical alignment */
    }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;header class="jumbotron banner"&gt;
    &lt;div class="container"&gt;
      &lt;h1&gt;Title&lt;/h1&gt;
  
      &lt;p&gt;Subtitle&lt;/p&gt;
      &lt;p&gt; &lt;a class="btn btn-lg btn-primary" href="#" role="button"&gt;Button&lt;/a&gt;
  
      &lt;/p&gt;
    &lt;/div&gt;
  &lt;/header&gt;</code></pre>
  </div>
  </div>
  </p>