title: react/semantic-ui: How to get a fullscreen segment
body: <p>I would like to build a layout like the homepage example of semantic-ui: <a href="http://semantic-ui.com/examples/homepage.html" rel="nofollow noreferrer">http://semantic-ui.com/examples/homepage.html</a></p>
  
  <p>The first vertical black segment has nearly full height. It is done by the <code>masthead</code> class, but I don't understand from where this class comes.</p>
  
  <p>I'm using react, so this is my layout so far:</p>
  
  <pre><code>render() {
      return (
          &lt;div&gt;
              &lt;Segment vertical inverted&gt;
                  &lt;p&gt;Main&lt;/p&gt;
              &lt;/Segment&gt;
              &lt;Segment vertical&gt;
                  &lt;p&gt;First&lt;/p&gt;
              &lt;/Segment&gt;
          &lt;/div&gt;
      )
  }
  </code></pre>
  
  <p>But with this the first segment doesn't have full height.</p>