JSFiddle - React, Tailwind, and code Playground

HTML

<div id='headerBar'>
    <div id='headerBarContent'>
        <div id='leftContentSubdiv'></div>
        <div id='rightContentSubdiv'></div>
    </div>
</div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br /></div>
<div>ASasd jasd kadj as dja da <br...

CSS

#headerBar
{
    position: fixed;
    left: 0px;
    right: 0px;
    background:red;
    min-width: 1024px;
    width: 100%;
    height: 34px;

    z-index: 10000;
}

#headerBarContent
{
    display: inline-block;

    position: absolute;
    left: 50%;
    margin-left: -512px;
    background:yellow;
    width: 1024px;
}

#leftContentSubdiv, #rightContentSubdiv
{
    position: relative;
    background:green;
    width: 512px;
    height: 34px;
}

@media screen and (max-width: 800px){
    #headerBar{
        position:relative;
    }
}