css/css-multicol/multicol-span-all-button-001-ref.html

<!DOCTYPE html>
<html>
  <meta charset="utf-8">
  <title>CSS Multi-column Layout Test: Test a multi-column container on button works with a column-span:all child</title>
  <link rel="author" title="Ting-Yu Lin" href="tlin@mozilla.com">
  <link rel="author" title="Mozilla" href="http://www.mozilla.org/">

  <style>
  button {
    width: 400px;
  }
  .inner {
    column-count: 3;
    column-rule: 6px solid;
  }
  h3 {
    column-span: all;
    outline: 1px solid blue;
  }
  </style>

  <button>
    <div class="inner">
      <div>block1</div><div>block2</div>
      <h3>spanner</h3>
      <div>block3</div><div>block4</div>
    </div>
  </button>
</html>