JSFiddle - React, Tailwind, and code Playground

HTML

<div class="fill">
  I fill the viewport!
</div>
<div class="normal">
  I'm just a normal div
</div>
<div class="fill">
  I fill the viewport, too!
</div>
<div class="normal">
  I'm just a normal div, too
</div>

CSS

body {
  margin: 0;
  padding: 0;
}

.fill {
  width: 100%;
  height: 100vh;
  background: green;
  text-align: center;
  color: white;
}

.normal {
  height: 100px;
}