title: margin-top only when the flex item is wrapped
body: <p>I have a flex container with two flex items. I want to set a margin-top on the second one, but only when it's wrapped and not at the first flex line.</p>
  
  <p>If possible, I want to avoid using media queries.</p>
  
  <p>I thought margin-bottom on the first element could be a solution. However, it adds space at the bottom when the elements are not wrapped, so same problem.</p>
  
  <p>This is my code:</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false">
  <div class="snippet-code">
  <pre class="snippet-code-css lang-css prettyprint-override"><code>.container {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-around;
  }
  .item-big {
    background: blue;
    width: 300px;
  }
  .item-small {
    background: red;
    margin-top: 30px;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;div class="container"&gt;
    &lt;div class="item-big"&gt;
      FIRST BIG ELEM
    &lt;/div&gt;
    &lt;div class="item-small"&gt;
      SECOND SMALL ELEM
    &lt;/div&gt;
  &lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>