Details + Tachyons example https://test.phonesites.com/dropdown-test

details-tachyons.html

<details class="pv1 ph2 ph4-ns mw6 center cf tc">
    <summary class="bg-blue link relative button-reset pv3 white db tc ba b--transparent bg-animate pointer w-100 br2 fw8">
      Details
    </summary>
    <ul class="list pl0 ml0 center mw6 ba b--light-silver br3">
      <li class="ph3 pv2 bb b--light-silver">
        <a href="#">Top Option</a>
      </li>
      <li class="ph3 pv2 bb b--light-silver">
        <a href="#">Middle Option(s)</a>
      </li>
      <li class="ph3 pv2">
        <a href="#">Bottom Option</a>
      </li>
    </ul>
</details>