JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
  <div class="box">:-)</div>
</div>

CSS

html, 
body {
  width: 100%;
  height: 100%;
  padding: 0;
  margin: 0;
  background: lightblue;
}

/* ------------- */

.container {
  min-width: 100%;
  min-height: 100%;
  background: red;
  
  display: flex;
  flex-direction: row;
  justify-content: center;
  align-items: center;
}

.box {
  background: yellow;
}