title: Trying to center div horizontally and vertically in screen
body: <p>I'm trying to make a div for my landing page of my website center in the very center of the screen, but it is not working. </p>
  
  <p>Here is my code</p>
  
  <p>CSS:</p>
  
  <pre><code>.centerDiv{
  width:800px;
  margin:0 auto;
  border-radius: 5px;
  background:#111;
  padding:10px;}
  </code></pre>
  
  <p>HTML:</p>
  
  <pre><code>&lt;div id="centerDiv" class="centerDiv"&gt;
     &lt;h1&gt;Title&lt;/h1&gt;
     &lt;p&gt;Text will go here.&lt;/p&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>Thanks.</p>