css3同心圆闪烁扩散效果

<!DOCTYPE html>

<html >

<head>

<meta charset="UTF-8">

<title>Document</title>

</head>

<style type='text/css'>

.circle{width:200px;height:200px;position:absolute;top:50%;left:50%;margin:-100px 0 0 -100px;}

.circle1, .circle2, .circle3, .center{

position:absolute;

left:50%;

top:50%;

margin:-30px 0 0 -30px;

width:60px;

height:60px;

border-radius:30px;

background-color:#666666;

}

.center{

position:absolute;

left:50%;

top:50%;

margin:-35px 0 0 -35px;

width:70px;

height:70px;

border-radius:35px;

background:#111111;/

text-align:center;

line-height:70px;

color:#EAEAEA;

font-size:16px;

font-family:'';

}

.circle1{

-webkit-animation:circle 3s linear infinite;

animation:circle 3s linear infinite;

}

.circle2{

-webkit-animation:circle 3s linear 0.8s infinite;

animation:circle 3s linear 0.8s infinite;

}

.circle3{

-webkit-animation:circle 3s linear 1.6s infinite;/* Safari and Chrome */

animation:circle 3s linear 1.6s infinite;

}

@-webkit-keyframes circle{ /* Safari and Chrome */

from{

opacity:1;

-webkit-transform:scale(0);

}

to{

opacity:0;

-webkit-transform:scale(3);

}

}

</style>

</head>

<body>

<div class='circle'>

<div class='circle1'>&nbsp;</div>

<div class='circle2'>&nbsp;</div>

<div class='circle3'>&nbsp;</div>

<div class='center'></div>

</div>

</body>

</html>