JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
    <div class="gray"></div>
    <div class="white"></div>
</div>

CSS

.container {
    height: 200px;
    overflow: hidden;
    position: relative;
}
.gray,
.white {
    position: absolute;
    left: -25%;
    right: -25%;
    border-radius: 100%;
}

.gray {
    top: -50%;
    border:100px solid gray;
    border-top: none;
    height: 200px;
}

.white {
    top: -80%;
    background-color: white;
    height: 300px;
}