JSFiddle - React, Tailwind, and code Playground

HTML

<body>
    <div class="mainSection sticky-ready">
        <header>
            <img src="http://placehold.it/300x80&text=Header+and+Nav" width="300" height="80" alt="header">
        </header>
        <section class="content clearfix">
            <section class="left">
                 <h1 class="headlineBar"><img src="http://placehold.it/200x40/A9200D/ffffff/&text=Headlines"></h1>

                <ul>
                    <li>
                        <img src="http://placehold.it/200x140/aaaaaa/ffffff&text=Story+Item">
                    </li>
                    <li>
                        <img src="http://placehold.it/200x140/777777/ffffff/&text=Story+Item">
                    </li>
                    <li>
                        <img src="http://placehold.it/200x140/aaaaaa/ffffff&text=Story+Item">
                    </li>
                    <li>
                        <img src="http://placehold.it/200x140/777777/ffffff/&text=Story+Item">
                    </li>
                    <li>
                        <img src="http://placehold.it/200x140/aaaaaa/ffffff&text=Story+Item">
                    </li>
                    <li>
                        <img src="http://placehold.it/200x140/777777/ffffff/&text=Story+Item">
                    </li>
                    <li>
                        <img src="http://placehold.it/200x140/aaaaaa/ffffff&text=Story+Item">
                    </li>
                    <li>
                        <img src="http://placehold.it/200x140/777777/ffffff/&text=Story+Item">
                    </li>
                    <li>
                        <img src="http://placehold.it/200x140/aaaaaa/ffffff&text=Story+Item">
                    </li>
                    <li>
                        <img src="http://placehold.it/200x140/777777/ffffff/&text=Story+Item">
                    </li>
                    <li>
                        <img src="http://placehold.it/200x140/aaaaaa/ffffff&text=Story+Item">
               ...

CSS

/* LAYOUT */
 .mainSection {
    margin:0 auto;
    width:350px;
}

aside {
    width:100px;
    float:left;
}
.left {
    
    width:200px;
    float:left;
}
.right {
    float:right;
}
/* Sticky Control */
 .sticky-ready .sticky {
    position:fixed !important;
}
.headlineBar {
    position:relative;
    z-index:10;
}
/* #Reset & Basics (Inspired by E. Meyers)
================================================== */
 html, body, div, span, applet, object, iframe, h1, h2, h3, h4, h5, h6, p, blockquote, pre, a, abbr, acronym, address, big, cite, code, del, dfn, em, img, ins, kbd, q, s, samp, small, strike, strong, sub, sup, tt, var, b, u, i, center, dl, dt, dd, ol, ul, li, fieldset, form, label, legend, table, caption, tbody, tfoot, thead, tr, th, td, article, aside, canvas, details, embed, figure, figcaption, footer, header, hgroup, menu, nav, output, ruby, section, summary, time, mark, audio, video {
    margin: 0;
    padding: 0;
    border: 0;
    font-size: 100%;
    font: inherit;
    vertical-align: baseline;
}
article, aside, details, figcaption, figure, footer, header, hgroup, menu, nav, section {
    display: block;
}
body {
    line-height: 1;
}
ol, ul {
    list-style: none;
}
blockquote, q {
    quotes: none;
}
blockquote:before, blockquote:after, q:before, q:after {
    content:'';
    content: none;
}
table {
    border-collapse: collapse;
    border-spacing: 0;
}

JavaScript

$(function () {


    var headlineBarPos = $('.headlineBar').offset().top; // returns number
var moduleControllerPos = $('.moduleController').offset().top; // returns number    
    var sidebarHeight = $('.sticky-sidebar-wrap').height();
    var sidebarTop = $('.sticky-sidebar-wrap').offset().top;
    var windowHeight = $(window).height();

    var totalHeight = sidebarHeight + sidebarTop;

    $(window).scroll(function () { // scroll event 

        var windowTop = $(window).scrollTop(); // returns number
        
        // fixing the headline bar    
        if (headlineBarPos < windowTop) {
            $('.headlineBar').addClass('sticky').css('top', '0');
        } else {
            $('.headlineBar').removeClass('sticky').removeAttr('style');
        }
        
        if (moduleControllerPos < windowTop + windowHeight) {
            $('.sticky-sidebar-wrap').addClass('sticky').css('top', '0');
        } else {
$('.sticky-sidebar-wrap').removeClass('sticky').removeAttr('style');        }

       




        console.log(windowTop);

    });


    console.log(headlineBarPos);
    console.log(sidebarHeight);
    console.log(sidebarTop);

});