JSFiddle - React, Tailwind, and code Playground

HTML

<div>Board</div>

CSS

div {
    width: 180px;
    border-radius: 30px;
    padding: 20px;
    line-height: 10px;
    font-size: 16px;
    color: #FFF;
    position: relative;
    overflow: hidden;
}
div:before, div:after {
    content:"";
    position: absolute;
    left: 18px;
    width: 180px;
    height: 20px;
    border-radius: 50%;
    z-index: -1;
}
div:before {
    top: -15px;
    box-shadow: 0 -9970px 0 10000px black;
}
div:after {
    bottom: -15px;
    box-shadow: 0 9970px 0 10000px black;
}
body {
    background-color: cornflowerblue;
}