 does not work when the machine is slow
      (e.g. When you show "Layers" in Chrome Devtool)
    </p>
    <div style="width:100%">
      <div
        id="box3"
        style="width:100px;height:100px;background-color: orange"
      ></div>
      <button id="btn3">Go</button>
    </div>
    <script id="code3">
      ;(function() {
        const box = document.getElementById("box3")
        document.getElementById("btn3").addEventListener("click", () => {
          const box = document.getElementById("box3")