title: Button width as a percentage of parent
body: <p>I want to my button to spread out 90% of the width of my screen.</p>
  
  <p>When I run my HTML, the button is just about 10% of the screen. However, if I set the width to a number with pixels, it resizes fine.</p>
  
  <p>What's going wrong?</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-css lang-css prettyprint-override"><code>.quiz {
    /*top: 240px;*/
    position: fixed;
    z-index: -1;
  }
  
  .quiz button {
    width: 90%;
    border-radius: 8px;
    display: block;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;div class="quiz"&gt;
    &lt;button&gt;Option 1&lt;/button&gt;
  &lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>