设置动画在两秒内完成 - 在线编辑器

          <html>
<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <style>
    div {
      width: 100px;
      height: 100px;
      background: red;
      position: relative;
      animation: mymove infinite;
      animation-duration: 2s;

      /* Safari and Chrome */
      -webkit-animation: mymove infinite;
      -webkit-animation-duration: 2s;
    }

    @keyframes mymove {
      from {
        top: 0px;
      }
      to {
        top: 200px;
      }
    }

    @-webkit-keyframes mymove
    /* Safari and Chrome */

    {
      from {
        top: 0px;
      }
      to {
        top: 200px;
      }
    }
  </style>
</head>
<body>

  <p><strong>注意:</strong> animation-duration属性不兼容 Internet Explorer 9 以及更早版本的浏览器.</p>

  <div></div>

  <p><b>注意:</b> 要指定动画属性。否则时间若是0,动画不会进行。</p>

</body>
</html>
        