简单CSS3动画

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <style type="text/css">
        body{
            font-size:12px;
            margin:0;padding:0;
        }
        #box{
            width:300px;
            height: 300px;
            margin:100px auto;
            border:1px solid #ccc;
            transition: all 0.3s;
            -webkit-transition: all 0.3s;
        }
        .inner-box{
            width:60px;
            height: 30px;
            margin:100px auto;
            border:1px solid #ccc;
            transition: all 0.3s;
            -webkit-transition: all 0.3s;
        }

@-webkit-keyframes myfirst /* Safari 和 Chrome */
{
from{transform:rotate(0deg);}
to {transform:rotate(360deg);}
}

        #box:hover{
            border-radius: 50%;
            background:#007aff;
            box-shadow: 5px 10px 10px rgba(0,0,0,.3);

            -webkit-animation: myfirst 3s;
            -webkit-animation-iteration-count:3;
            -webkit-animation-direction:alternate;

        }
    </style>
</head>

<body>
    <div id="box">
        <div class="inner-box"></div>
        <div class="inner-box"></div>
    </div>
</body>
</html>