<head>
<meta charset="UTF-8">
<title></title>
<style type="text/css">
#box{
position: relative;
width: 100px;
margin: 100px auto 0;
}
span{
position: absolute;
width: 50px;
height: 50px;
border: 5px solid #fff;
border-radius: 50%;
-webkit-animation: a 4s infinite linear;
}
span:nth-child(1){
-webkit-animation-delay: 0s;
}
span:nth-child(2){
-webkit-animation-delay: 0.66s;
}
span:nth-child(3){
-webkit-animation-delay: 1.33s;
}
@-webkit-keyframes a{
0%{-webkit-transform: scale(0); opacity: 0;}
25%{-webkit-transform: scale(0); opacity: 0.5;}
50%{-webkit-transform: scale(1); opacity: 1;}
75%{-webkit-transform: scale(1.5); opacity: 0.5;}
100%{-webkit-transform: scale(2); opacity: 0;}
}
</style>
</head>
<body style="background-color: darkgreen;">
<div id="box">
<span></span>
<span></span>
<span></span>
</div>
</body>