JSFiddle - React, Tailwind, and code Playground

HTML

<div class="jedna"></div>

<div class="dva"></div>

<div class="tri"></div>

CSS

body {
    background-color: #EEE;
}
.jedna {
    background: #232323;
    width: 100px;
    height: 100px;
    position: absolute;
    z-index: 2;
    left: 80px;
    top: 80px;
}
.dva {
    background: #ff0000;
    width: 100px;
    height: 100px;
    position: absolute;
    z-index: 0;
}

.tri {
    background: #FFF000;
    width: 100px;
    height: 100px;
    position: absolute;
    z-index: 1;  
    left: 40px;
    top: 40px;
}