JSFiddle - React, Tailwind, and code Playground

HTML

<div></div>

CSS

body{
    background: url('http://www.zeppelin.ru/i/main_back.png');
}
div {
    margin: 20px 0;
    height: 50px;
    background-color: #543E3F;
    border-radius: 20px;
    background: radial-gradient(110% 20px at center top, transparent 40%, #543E3F 42%);
}