JSFiddle - React, Tailwind, and code Playground

HTML

<div class="parent">
    <div class="child"></div>
</div>

CSS

div.parent {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 500px;
    background: blue;
}
.child {
  width: 200px;
  height: 200px;
  background: red;
}