.strange-shape {
border-radius: 50px 120px 75px 10px / 100px 10% 30px 100px;
/* same as */
border-top-left-radius: 50px / 100px;
border-top-right-radius: 120px / 10%;
border-bottom-right-radius: 75px / 30px;
border-bottom-left-radius: 10px / 100px;
}