.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%
        )
    }