跟着圆形边框走的八卦

style样式代码：

 <style>
        body{
            background-color: lightcyan;
            width: 600px;height: 600px;
            border-radius: 50%;
            border: 1px solid gray;
            animation:bagua 5s linear  infinite;

        }
        @keyframes bagua{
            100%{transform: rotate(720deg)}
        }

        #bagua {
            margin-left: 200px;
            width: 0px;
            height:200px;
            position:relative;
            border-left:100px solid black;
            border-right:100px solid white;
            border-radius:50%;
        }


        #bagua:before,#bagua:after{
            position:absolute;
            content:"";
        }

        #bagua:before {
            width:100px;height:100px;
            top:0;left:-50px;
            z-index:5;
            background-color:white;border-radius:50%;
            box-shadow:0 100px 0px  black;
        }

        #bagua:after {
            width:30px;height:30px;
            top:35px;left:-30px;z-index:10;
            background-color:black;border-radius:50%;
            box-shadow:0 100px 0px white;
        }



    </style>

html代码：

<div id="bagua"></div>