JSFiddle - React, Tailwind, and code Playground

HTML

<div class="box move z20">
  dfs
</div>


<div class='section withWillChange z30'>
</div>
<!-- 
-->

<div class='section withPosition z30'>
</div>


<div class='withGrid'>
  <div class='section z30'>
  </div>
</div>

CSS

.box{
  width: 90px;
  height: 90px;
  background-color: coral;
}
.section{
  background-color: cadetblue;
  min-height: 900px;
  padding-top: 50px;
}

.move{
  position: relative;
  top: 50px;
  left: 50px;
}

.withPosition{
  position: relative;
}

.withGrid{
  display: grid;
}

.withWillChange{
  will-change: opacity;
  opacity: 99;
}

.z20{
  z-index: 20;
}
.z30{
  z-index: 30;
}