title: Pseudo elements breaking justify-content: space-between in flexbox layout
body: <p>I have three divs inside a parent div that are being spaced out using:</p>
  
  <pre><code>display: flex;
  justify-content: space-between;
  </code></pre>
  
  <p>However, the parent div has an <code>:after</code> on it which is making the three divs not go out to the edge of parent div. Is there a way to have flexbox ignore the <code>:before</code> and <code>:after</code>?</p>
  
  <p><a href="http://codepen.io/landon1013/pen/pNRNvg" rel="noreferrer">codepen.io</a></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>.container {
    width: 100%;
    display: flex;
    justify-content: space-between;
    padding-top: 50px;
    background: gray;
  }
  
  .container div {
      background: red;
      height: 245px;
      width: 300px;
    }
  .container:before {
      content: '';
      display: table;
    }
  .container:after {
      clear: both;
      content: '';
      display: table;
    }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;div class="container"&gt;
    &lt;div&gt;&lt;/div&gt;
    &lt;div&gt;&lt;/div&gt;
    &lt;div&gt;&lt;/div&gt;
  &lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>