简单的球体运动制作

<!DOCTYPE html>
<html lang="zh-cn">
<head>
    <meta charset="utf-8" />
    <title></title>
    <style>
        .circle{
            margin: 0 auto;
            width: 200px;
            height: 200px;
            opacity: 0.7;
            display: block;
            background-image: radial-gradient(circle at 120px 80px,#5cabff ,#000); /* 径向渐变 */
            border-radius: 50%;    /* 对球体进行初始化 */
            /*box-shadow: -3px -3px 3px #000;*/
            -webkit-animation:move 2s ease-in-out infinite reverse;
        }   

        .circle_shadow{  /* 阴影配合球体运动，看起来更立体 */
            margin: 500px auto;
            width: 200px;
            height: 5px;
            background-color: #ccc;
            border-radius: 50%;
            -webkit-animation:shadow 2s ease-in-out infinite;  
        }
     

        @-webkit-keyframes move{
            0%{ -webkit-transform:translateY(0px); }

            50%{ -webkit-transform:translateY(500px); }
           
            100%{ -webkit-transform:translateY(0px); }
        }

        @-webkit-keyframes shadow{
            0%{width:50px;}
            25%{width:125px;}
            50%{width:200px;}
            25%{width:125px;}
            100%{width:50px;}
        }
    </style>
</head>
<body>
   <div class="box">
        <div class="circle"> </div>
    <div class="circle_shadow"></div>
   </div>
</body>
</html>
效果图