JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
  <div class="circle"></div>
</div>

CSS

.container {
  display: flex;
  background-color: tomato;
  width: 100vw;
  height: 100vh;
}

.circle {
  margin: auto;
  width: 200px;
  height: 200px;
  border-radius: 50%;
  border: 10px solid #fff;
  box-shadow: 0 0 0 9999px rgba(0, 0, 0, .5);
}