title: <DOCTYPE html> versus <html> - rendering problems firefox and chrome
body: <p>have been using no <code>DOCTYPE</code> but rather simply starting with <code>&lt;html&gt;</code> as per HTML5 standards (as I understood them).  everything going ok.</p>
  
  <p>began using <code>Jade</code>, which insists on <code>DOCTYPE</code>. using <code>&lt;!DOCTYPE html&gt;</code> - pages no longer render correctly(?).</p>
  
  <p>as an easy and trivial example (behavior is same on firefox and chrome):</p>
  
  <pre><code>&lt;html&gt;
      &lt;body &gt;
          &lt;div style='height:50%; background-color:pink;'&gt;&lt;/div&gt;
          &lt;div style='height:50%; background-color:blue;'&gt;&lt;/div&gt;
      &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>render just fine - have page pink, half blue</p>
  
  <pre><code>&lt;!DOCTYPE html&gt;
  &lt;html&gt;
      &lt;body &gt;
          &lt;div style='height:50%; background-color:pink;'&gt;&lt;/div&gt;
          &lt;div style='height:50%; background-color:blue;'&gt;&lt;/div&gt;
      &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>renders two skinny DIV's you can't see.</p>
  
  <ol>
  <li>what's going on?</li>
  <li>thought <code>DOCTYPE</code> was being deprecated for HTML5</li>
  <li>what should I be doing?</li>
  </ol>