JSFiddle - React, Tailwind, and code Playground

HTML

<div class="content">
    <div class="left"></div>
    <div class="right">
        Protocol -- Specifies the protocol name be used to access the resource on the Internet. (HTTP (without SSL) or HTTPS (with SSL))

hostname -- Host name specifies the host that owns the resource. For example, www.stackoverflow.com. A server provides services using the name of the host.

port -- A port number used to recognize a specific process to which an Internet or other network message is to be forwarded when it arrives at a server.

pathname -- The path gives info about the specific resource within the host that the Web client wants to access. For example, stackoverflow.com/index.html.

query -- A query string follows the path component, and provides a string of information that the resource can utilize for some purpose (for example, as parameters for a search or as data to be processed).

hash -- The anchor portion of a URL, includes the hash sign (#).
        <div class="scroll">
            <h1>Fixed Top</h1>
            Protocol -- Specifies the protocol name be used to access the resource on the Internet. (HTTP (without SSL) or HTTPS (with SSL))

hostname -- Host name specifies the host that owns the resource. For example, www.stackoverflow.com. A server provides services using the name of the host.

port -- A port number used to recognize a specific process to which an Internet or other network message is to be forwarded when it arrives at a server.

pathname -- The path gives info about the specific resource within the host that the Web client wants to access. For example, stackoverflow.com/index.html.

query -- A query string follows the path component, and provides a string of information that the resource can utilize for some purpose (for example, as parameters for a search or as data to be processed).

hash -- The anchor portion of a URL, includes the hash sign (#).Protocol -- Specifies the protocol name be used to access the resource on the Internet. (HTTP (without...

CSS

.content {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    overflow: hidden;
}
.left {
    position: absolute;
    top: 0;
    left: 0px;
    width: 20px;
    bottom: 0;
    background: red;
}
.right {
    position: absolute;
    top: 0;
    bottom: 0;
    left: 20px;
    right: 0;
    overflow: auto;
    background: #f5f5f5;
}
.scroll {
    background: yellow;
}

JavaScript

$(document).ready(function() {
    $('.right').scroll(function() {
        if ($('.scroll').offset().top <= 0) {
            $('.scroll').css({
                'position': 'fixed',
                'top': 0,
                'left': '20px',
                'right': '0',
                'overflow': 'auto'
            })
        }
    })
})