@momentum-ui/react-collaboration/scss/components/collapse-button/examples/expanded.html

Cisco Momentum UI Framework for React Collaboration Applications

<button
  class="md-button md-button--36 md-collapse-button md-collapse-button--left"
  alt="collapse"
  type="button"
  aria-label="collapse"
  tabindex="0"
>
  <span class="md-button__children" style="opacity: 1;">
    <i
      class="md-icon icon icon-panel-control-left_12"
      style="font-size: 12px;"
    ></i>
  </span>
</button>