JSFiddle - React, Tailwind, and code Playground

HTML

<div class="toto">
  
</div>

CSS

html {
  background-color: red;
  height: 100%;
}
body {
  background-color: green;
  height: 100%;
  margin:0;
}
.toto {
  background-color: blue;
  width: 100px;
  height: 100px;
  margin-top:50px;
}