JSFiddle - React, Tailwind, and code Playground

by vjeux

HTML

<div class="container">
    <div class="a">a</div>
    <div class="b">b</div>
</div>

CSS

div {
    display: flex;
    flex-direction: column;
    opacity: 0.9;
    margin: 10px;
}
.container {
    background: black;
    height: 200px;
    position: relative;
}
.a {
    background: red;
    position: absolute;
    flex: auto;
    z-index: 5;
}
.b {
    background: blue;
    flex: auto;
}