<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
@keyframes aaa {
from {-webkit-transform: scale(1);
transform: scale(1);}
to{-webkit-transform: scale(2);
transform: scale(2);}
}
#aaa{
margin:200px auto;
width:250px;
height:250px;
background: red;
border-radius: 50%;
}
#aaa:hover{
animation: aaa 0.1s ease-in 0s infinite alternate;
}
</style>
</head>
<body>
<div id="aaa"></div>
</body>
</html>
CSS3的animation+scale实现视觉冲击力的效果
原文：http://www.cnblogs.com/qiancheng123/p/6337295.html