examples/show-on-initial-load.html

<!DOCTYPE html>
<html>
  <head>
    <link href="../css/perfect-scrollbar.css" rel="stylesheet">
    <script src="../dist/perfect-scrollbar.js"></script>
    <style>
    #container {
      position: relative;
      margin: 0px auto;
      padding: 0px;
      width: 600px;
      height: 400px;
      overflow: auto;
    }
    #container .content {
      background-image: url('./assets/azusa.jpg');
      width: 1280px;
      height: 720px;
    }
    </style>
  </head>
  <body>
    <div id="container">
      <div class="content">
      </div>
    </div>

    <script>
    var $ = document.querySelector.bind(document);

    new PerfectScrollbar('#container');
    setTimeout(() => $('#container').classList.add('ps--focus'), 0);
    setTimeout(() => $('#container').classList.remove('ps--focus'), 750);
    </script>
  </body>
</html>