JSFiddle - React, Tailwind, and code Playground

HTML

<div id="jedna">
    <div id="dva"></div>
</div>

CSS

body {
    background-color:black;
    
}
#jedna {
    width:200px;
    height:200px;
    background-color:white;
    position:absolute;
    z-index:-2;
    
}
#dva {
    width:200px;
    height:200px;
    background-color:red;
    z-index:1;
    margin:50px;
  
}