JSFiddle - React, Tailwind, and code Playground

HTML

<div id="outer">div. This is a div. This is a div. This is a div. This is a div. This is a div. This is a div. This is a div. This is a div. This is a div. This is a div
</div>

CSS

body, html{
  height: 100%;
  margin: 0;
  padding: 0;
  background-color: blue;
  padding: 2px;
}

#outer{
  width: 100%;
  height: 100%;
  padding: 2px;
  background-color: red;
}

#inner{
  width: 100%;
  min-height: 100%;
  max-height: auto;
  background-color: yellow
}