JSFiddle - React, Tailwind, and code Playground

HTML

<div id='one'>

Navi bar
</div>

<pre...

CSS

body {
  display: flex;
  flex-direction: column;
  height: 100vh;
  margin: 0px;
}

#one {
  background-color: red;
}

#two {
  margin-top: 0px;
  background-color: black;
  color: white;
  overflow-y: scroll;
}