OverlayScrollbars/packages/overlayscrollbars/test/playwright/setups/structureSetup/observers/index.html

<div id="controls">
  <button id="start">start</button>
</div>
<div id="stage">
  <div>
    <div id="target" class="container">
      <span>Hello</span>
    </div>
  </div>
</div>