JSFiddle - React, Tailwind, and code Playground

HTML

<hr>

CSS

* {
  box-sizing: border-box
}

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

hr {
  width: 50%;
  height: 2px;
  border: 0;
  margin: 1em auto;
  background: violet;
  
}