   <aside>
      Tap to lift/drop the card.
      <br>
      Current z-index = <span id="card-z">0</span>
    </aside>
    <script>
      document.addEventListener('polymer-ready', function() {
        var fab = document.getElementById('card');
        fab.addEventListener('shadow-z-changed', function() {
          document.getElementById('card-z').textContent = fab.z;
        });
      });
    </script>
  </section>

  <section>
    <div>
      <style>
        x-shadow.fab {
          margin: 48px 142px;
 