JSFiddle - React, Tailwind, and code Playground

by skirtle

HTML

<div class="outer" onclick="event.target.className += ' other'">
  <div class="inner">
  </div>
</div>

CSS

.outer {
  background: #000;
  height: 100vh;
  width: 100vw;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 2s;
}

.other {
  background: #fff;
}

.inner {
  height: 200px;
  width: 200px;
  background: #c60;
}