<head>
<meta charset="UTF-8">
<title></title>
<style type="text/css">
#box{
width: 400px;
height: 400px;
margin: 100px auto 0;
position: relative;
}
span{
position: absolute;
width: 16px;
height: 16px;
border-radius: 50%;
background: #fff;
-webkit-animation: a 1s infinite linear;
}
span:nth-child(1){
left: 0px;
-webkit-animation-delay: 0s;
}
span:nth-child(2){
left: 20px;
-webkit-animation-delay: 0.25s;
}
span:nth-child(3){
left: 40px;
-webkit-animation-delay: 0.5s;
}
span:nth-child(4){
left: 60px;
-webkit-animation-delay: 0.75s;
}
span:nth-child(5){
left: 80px;
-webkit-animation-delay: 1s;
}
@-webkit-keyframes a{
0%{-webkit-transform: translateY(0px); opacity: 0.5;}
50%{-webkit-transform: translateY(-30px); opacity: 1;}
100%{-webkit-transform: translateY(0px); opacity: 0.5;}
}
</style>
</head>
<body style="background-color: royalblue;">
<div id="box">
<span></span>
<span></span>
<span></span>
<span></span>
<span></span>
</div>
</body>