<head>
<meta charset="UTF-8">
<title></title>
<style type="text/css">
.quan{
position: relative;
border: 4px solid rgba(255,255,255,.25);
width: 80px;
height: 80px;
border-radius: 50%;
-webkit-animation: a 1s infinite linear;
}
span{
position: absolute;
width: 80px;
height: 80px;
border: 4px solid transparent;
border-top: 4px solid #fff;
top: -4px;
left: -4px;
border-radius: 50%;
}
@-webkit-keyframes a{
0%{-webkit-transform: rotate(0deg);}
100%{-webkit-transform: rotate(360deg);}
}
</style>
</head>
<body style="background-color: palevioletred;">
<div class="quan">
<span id=""></span>
</div>
</body>
原文：http://www.cnblogs.com/luckyXcc/p/5721089.html