.basis {

    width: 250px;

    height: 250px;

    margin: 50px auto;

    background: conic-gradient(#000 12.5%, #fff 0 37.5%, #000 0 62.5%, #fff 0 87.5%, #000 0);

    border: 5px solid #999;

}

​

.wallpaper {

    width: 250px;

    height: 250px;

    margin: 50px auto;

    background: conic-gradient(#000 12.5%, #fff 0 37.5%, #000 0 62.5%, #fff 0 87.5%, #000 0);

    background-size: 50px 50px;

    border: 5px solid #999;

}

​

.wallpaper2 {

    width: 250px;

    height: 250px;

    margin: 50px auto;

    background: conic-gradient(#000 12.5%, #fff 0 37.5%, #000 0 62.5%, #fff 0 87.5%, #000 0);

    background-size: 50px 50px;

    border-radius: 50%;

    border: 5px solid #999;

}