JSFiddle - React, Tailwind, and code Playground

HTML

<div class="outer">
  <div class="inner"></div>
  <p>Hello World</p>
</div>

CSS

.outer {
  display: table-cell;
  text-align: center;
  vertical-align: middle;
  border: 1px solid red;
  width: 500px;
  height: 800px;
}

.inner {
  height: 100px;
  width: 100px;
  margin: 0 auto;
  border: 1px solid blue;
}