round-color: blue;
    height: 100px;
    position: relative;
    transition-duration: 2s;
    transition-property: top;
    transition-timing-function: linear;
    width: 100px;
  }
</style>
<body>
  <p>Click blue square below. Test passes if the blue square moves down gradually not immediately until it stops.</p>
  <div id="test"></div>
  <script>
    (function() {
      var test = document.querySelector("#test");
      test.addEventListener("click", function(evt) {
        test.setAttribute("style", "top