JSFiddle - React, Tailwind, and code Playground

HTML

<div></div>

CSS

* {
  box-sizing: border-box
}

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

div {
  height: 100px;
  background: linear-gradient(-45deg, red 50%, darkred 50.1%);
}