JSFiddle - React, Tailwind, and code Playground
HTML
<div class="container"><div class="content"><div class="banner">abs el inside</div></div></div>CSS
body { margin: 0; }
.container {
background: black;
}
.content {
height: 300px;
background: blue;
}
.banner {
width: 50px;
height: 50px;
background: #bada55;
position: relative;
}