title: Make empty div of one line height
body: <p>Is it possible to create a rule that will make the following HTML:</p>
  
  <pre><code>&lt;div style="width: 100%"&gt;&lt;/div&gt;
  </code></pre>
  
  <p>of one line height using just CSS, or do I need to put <code>&amp;nbsp;</code> as the content?</p>