<html>
<head>
<style>
div
{
width:100px;
height:100px;
background:red;
position:relative;
animation:myfirst 5s infinite;
animation-direction:alternate;
/* Safari 和 Chrome */
-webkit-animation:myfirst 5s infinite;
-webkit-animation-direction: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;}
}
@-webkit-keyframes myfirst /* Safari 和 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;}
}
</style>
</head>
<body>
<p><strong>注意：</strong>Internet Explorer 9 及其之前的版本不支持 animation-direction 属性。</p>
<div></div>
</body>
</html>