JSFiddle - React, Tailwind, and code Playground

HTML

<div class="root">
  <div class="child1"></div>
  <div class="child2"></div>
</div>

CSS

.root {
    position: relative;
    z-index: 1;
    background-color: black;
    margin-top: 100px;
    width: 800px;
    height: 800px;
}

.root >.child1 {
    float: right;
    width: 300px;
    height: 300px;
    background-color: red;
}

.root >.child2 {
    position: relative;
    top: -50px;
    width: 300px;
    height: 300px;
    background-color: blue;
}