JSFiddle - React, Tailwind, and code Playground

HTML

<div id="parent">
    <div id="child"></div>
</div>

<div id="sibling">
</div>

CSS

div { width: 100px; height: 100px; position: absolute; }

#parent {
    z-index: 100;
    top: 0;
    left: 0;
    background-color: red;
}

#child {
    z-index: 102;
    left: 20px;
    top: 20px;
    background-color: orange;
}

#sibling {
    z-index: 101;
    top: 10px;
    left: 10px;
    background-color: green;
}