JSFiddle - React, Tailwind, and code Playground

HTML

<div id="fixed">Fixed Position</div>
<div id="relative">Relative Position</div>

CSS

body{
    height: 3000px;
}

#fixed{
    top: 0;
    height; 100px;
    background: green;
    width: 100%;
    position: fixed;
    z-index: 2;
}

#relative{
    position: relative;
    top: 100px;
    left: 50px;
    height: 100px;
    width: 100px;
    background: red;
    z-index: 1;
}