chromium/third_party/blink/web_tests/external/wpt/css/css-multicol/multicol-span-all-dynamic-add-008-ref.html

<!DOCTYPE html>
<html>
  <meta charset="utf-8">
  <title>CSS Multi-column Layout Test Reference: Add a nested multi-column spanner to the outer column</title>
  <link rel="author" title="Ting-Yu Lin" href="mailto:[email protected]">
  <link rel="author" title="Mozilla" href="http://www.mozilla.org/">

  <style>
  #column {
    column-count: 3;
    column-rule: 6px solid;
    width: 400px;
    outline: 1px solid black;
  }
  h3 {
    column-count: 2;
    column-span: all;
    outline: 1px solid blue;
  }
  </style>

  <body>
    <article id="column">
      <div>block1</div>
      <h3>multi-column spanner</h3>
      <h3>spanner</h3>
      <div>block2</div>
    </article>
  </body>
</html>