JSFiddle - React, Tailwind, and code Playground

HTML

<div id="wrapper">
  
  <div class="child">div1</div>
  
  <div class="child">div2</div>

</div>

CSS

html,body {
  height:100%;
}

#wrapper {
  background:aqua;
  height:100%;
}

.child {
  height:100%;
}