side>
      z-depth = 4
    </aside>
  </section>

  <section>
    <div>
      <div class="card paper-shadow-top-z-5">
        <div class="card-inner paper-shadow-bottom-z-5">
        </div>
      </div>
    </div>
    <aside>
      z-depth = 5
    </aside>
  </section>

  <br>
  <br>
  <br>
  <br>

  <polymer-element name="x-shadow" attributes="z" on-tap="{{tapAction}}">
    <template>
      <style>
        :host,
        .paper-shadow-bottom {
          display: block;
          background: white;
       