.box{    border:5px solid #333;    border-radius:500px;    width:500px;    height:500px;    position: relative;    overflow:hidden;    }.back{    background: #000;    width: 250px;    height: 250px;    position: absolute;    border-radius: 500px;    left: 25%;    }.backs{    background: #fff;    width: 250px;    height: 250px;    position: absolute;    border-radius: 500px;    left: 25%;    bottom:0;    }.right_d{    background:#000;    width:250px;    height:500px;    right:0;    position:absolute;}.n1{    background:#fff;    width:100px;    height:100px;    border-radius:100px;    position:absolute;    top:25%;    left:25%;}.n2{    background:#000;    width:100px;    height:100px;    border-radius:100px;    position:absolute;    bottom:25%;    left:25%;}