title: input fields not responding to display flex
body: <p>I have a set of input fields that look like so:</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>.input-set {
    display: flex;
    align-items: center;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;div class="input-set"&gt;
    &lt;div class="group-1"&gt;
      &lt;input class="input" /&gt;
      &lt;input class="input" /&gt;
      &lt;input class="input" /&gt;
    &lt;/div&gt;
  
    &lt;div class="group-2"&gt;
      &lt;input class="input" /&gt;
      &lt;input class="input" /&gt;
      &lt;input class="input" /&gt;
    &lt;/div&gt;
  
    &lt;div class="group-3"&gt;
      &lt;input class="input" /&gt;
      &lt;input class="input" /&gt;
      &lt;input class="input" /&gt;
    &lt;/div&gt;
  &lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>
  <p>However, the set of three inputs fields are still showing horizontally. I have added <code>display: flex;</code> to the groupings of inputs and it is still showing horizontally.</p>