title: Make flex items have equal width in a row
body: <p>I want the headers (<code>h4.child-title</code>) to have the same length within the parent container in the below example.</p>
  <p>But I'm not successful in achieving this.</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>.top-level {
    display: flex;
    flex-flow: row wrap;
  }
  
  .section {
    display: flex;
    flex-flow: row nowrap;
    border: 1px solid;
    margin-right: 12px;
    margin-top: 12px;
  }
  
  .section-child {
    display: flex;
    flex-flow: column nowrap;
    align-items: center;
    flex: 1 1 0;
  }
  
  .child-title {
    white-space: nowrap;
  }
  
  .vertical-separator {
    width: 1px;
    background-color: rgba(0, 0, 0, 0.3);
    margin: 8px;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;div class="top-level"&gt;
    &lt;section class="section"&gt;
      &lt;div claas="section-child"&gt;
        &lt;h4 class="child-title"&gt;Title&lt;/h4&gt;
        &lt;!--A lot more content here--&gt;
      &lt;/div&gt;
      &lt;div class="vertical-separator"&gt;&lt;/div&gt;
      &lt;div class="section-child"&gt;
        &lt;h4 class="child-title"&gt;Longer title&lt;/h4&gt;
        &lt;!--A lot more content here--&gt;
      &lt;/div&gt;
      &lt;div class="vertical-separator"&gt;&lt;/div&gt;
      &lt;div class="section-child"&gt;
        &lt;h4 class="child-title"&gt;Much much longer title&lt;/h4&gt;
        &lt;!--A lot more content here--&gt;
      &lt;/div&gt;
    &lt;/section&gt;
    &lt;section class="section"&gt;
      &lt;div claas="section-child"&gt;
        &lt;h4 class="child-title"&gt;Title&lt;/h4&gt;
        &lt;!--A lot more content here--&gt;
      &lt;/div&gt;
      &lt;div class="vertical-separator"&gt;&lt;/div&gt;
      &lt;div class="section-child"&gt;
        &lt;h4 class="child-title"&gt;Longer title&lt;/h4&gt;
        &lt;!--A lot more content here--&gt;
      &lt;/div&gt;
      &lt;div class="vertical-separator"&gt;&lt;/div&gt;
      &lt;div class="section-child"&gt;
        &lt;h4 class="child-title"&gt;Much much longer title&lt;/h4&gt;
        &lt;!--A lot more content here--&gt;
      &lt;/div&gt;
    &lt;/section&gt;
    &lt;section class="section"&gt;
      &lt;div claas="section-child"&gt;
        &lt;h4 class="child-title"&gt;Title&lt;/h4&gt;
        &lt;!--A lot more content here--&gt;
      &lt;/div&gt;
      &lt;div class="vertical-separator"&gt;&lt;/div&gt;
      &lt;div class="section-child"&gt;
        &lt;h4 class="child-title"&gt;Longer title&lt;/h4&gt;
        &lt;!--A lot more content here--&gt;
      &lt;/div&gt;
      &lt;div class="vertical-separator"&gt;&lt;/div&gt;
      &lt;div class="section-child"&gt;
        &lt;h4 class="child-title"&gt;Much much longer title&lt;/h4&gt;
        &lt;!--A lot more content here--&gt;
      &lt;/div&gt;
    &lt;/section&gt;
  &lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>