<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>文档标题</title>
<script src="https://www.imooc.com/static/lib/jquery/1.9.1/jquery.js"></script>
<style type="text/css">
.circle{
width:280px;
height:180px;
background:radial-gradient(closest-side,red 1%,yellow 10%,#00ffff 50%);
border-radius:50%;
position:absolute;
top:200px;
}
</style>
</head>
<body>
<div id="circle" class="circle" onmouseover="b()" onmouseout="d()"></div>
<input type="button" value="start" onclick="ae()"/>
<div id="seconds" class="second"></div>
<script type="text/javascript">
var e
function b(){$(".circle").animate({width:"-=10px", height:"+=10px",top:"-=15px",right:"-=15",opacity:"1"},3000);
}
function ae(){e=setInterval(b,1000)}
var w=$(".circle").width()
var h=$(".circle").height()
if(r==l){clearInterval(e)}
</script>
</body>
</html>
红尘往事，一切随风！
