JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html>
<html>
  <head>
    <style>
      .content {
        color: red;
        font-size: 24px;
      }
    </style>
  </head>

  <body>
    <p>Complete the form</p>
    <form id="form" action="URL" target="_self" method="POST">
      <div><input type="text" placeholder="name" required name="Name"></div>
      <div><input type="email" placeholder="email" required name="E-mail"></div>
      <div><button type="submit">Send</button></div>
    </form>
    <div id="content" style="display: none;" class="content">
      This is new content!
    </div>



    <script type="text/javascript">
      function f() {
        const elementToHide = document.getElementById("form");
        elementToHide.style.display = 'none';
        const elementToShow = document.getElementById("content");
        elementToShow.style.display = 'block';
      }
      const timerRef = setTimeout(f, 1000 * 10);

    </script>
  </body>

</html>