与上面的动画相同，但是使用了简写的动画 animation 属性 - 在线编辑器

          <!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <style>
    div {
      width: 100px;
      height: 100px;
      background: red;
      position: relative;
      animation: myfirst 5s linear 2s infinite alternate;
      /* Firefox: */
      -moz-animation: myfirst 5s linear 2s infinite alternate;
      /* Safari and Chrome: */
      -webkit-animation: myfirst 5s linear 2s infinite alternate;
      /* Opera: */
      -o-animation: myfirst 5s linear 2s infinite alternate;
    }

    @keyframes myfirst {
      0% {
        background: red;
        left: 0px;
        top: 0px;
      }
      25% {
        background: yellow;
        left: 200px;
        top: 0px;
      }
      50% {
        background: blue;
        left: 200px;
        top: 200px;
      }
      75% {
        background: green;
        left: 0px;
        top: 200px;
      }
      100% {
        background: red;
        left: 0px;
        top: 0px;
      }
    }

    @-moz-keyframes myfirst
    /* Firefox */

    {
      0% {
        background: red;
        left: 0px;
        top: 0px;
      }
      25% {
        background: yellow;
        left: 200px;
        top: 0px;
      }
      50% {
        background: blue;
        left: 200px;
        top: 200px;
      }
      75% {
        background: green;
        left: 0px;
        top: 200px;
      }
      100% {
        background: red;
        left: 0px;
        top: 0px;
      }
    }

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

    {
      0% {
        background: red;
        left: 0px;
        top: 0px;
      }
      25% {
        background: yellow;
        left: 200px;
        top: 0px;
      }
      50% {
        background: blue;
        left: 200px;
        top: 200px;
      }
      75% {
        background: green;
        left: 0px;
        top: 200px;
      }
      100% {
        background: red;
        left: 0px;
        top: 0px;
      }
    }

    @-o-keyframes myfirst
    /* Opera */

    {
      0% {
        background: red;
        left: 0px;
        top: 0px;
      }
      25% {
        background: yellow;
        left: 200px;
        top: 0px;
      }
      50% {
        background: blue;
        left: 200px;
        top: 200px;
      }
      75% {
        background: green;
        left: 0px;
        top: 200px;
      }
      100% {
        background: red;
        left: 0px;
        top: 0px;
      }
    }
  </style>
</head>
<body>

  <p><b>注意:</b> 该实例在 Internet Explorer 9 及更早 IE 版本是无效的。</p>

  <div></div>

</body>
</html>
        