.box{

        width: 100px;

        height: 100px;

        background: orange;

        border: 1px solid #000;

        border-radius: 20% 80% 30% 70%/80% 70% 30% 20%;

    }

.box{

        width: 100px;

        height: 100px;

        background: green;

        box-shadow: 0 0 0 2px blue,inset 0 0 20px #000,110px 0 0 2px blue;

    }

.box{

        width: 100px;

        height: 100px;

        border: 10px solid red;

        border-radius: 50%;

        background: linear-gradient(

            to right bottom,

            transparent 46%,

            red 46%,

            red 54%,

            transparent 54%

        )

    }