title: html button size height percentage
body: <p>How can I set the button size in HTML to be percentage of screen. Pixel units work but percentage does not.
  See this fiddle: <a href="https://jsfiddle.net/3po5o7cb/10/" rel="nofollow">https://jsfiddle.net/3po5o7cb/10/</a></p>
  
  <pre><code>&lt;button style="width:20%; height:20%"&gt;&lt;/button&gt;
  &lt;button style="width:200px;height:200px"&gt;&lt;/button&gt;
  </code></pre>