<div class="htmleaf-container">
    <div class="wrapper">
      <div class="container">
        <h1>Welcome</h1>

        <form class="form">
          <input type="text" placeholder="Username">
          <input type="password" placeholder="Password">
          <button type="submit" id="login-button">Login</button>
        </form>
      </div>

      <ul class="bg-bubbles">
        <li></li>
        <li></li>
        <li></li>
        <li></li>
        <li></li>
        <li></li>
        <li></li>
        <li></li>
        <li></li>
        <li></li>
      </ul>
    </div>
  </div>

  <script src="js/jquery-2.1.1.min.js" type="text/javascript"></script>
  <script>
    $('#login-button').click(function (event) {
      event.preventDefault();
      $('form').fadeOut(500);
      $('.wrapper').addClass('form-success');
    });
  </script>