JSFiddle - React, Tailwind, and code Playground

HTML

<div id="top"></div>
<div id="menu"></div>
<div id="page"></div>

CSS

#top {
height:200px;
background:red;
width:100%;
}
#menu {
height:80px;
background:black;
width:100%;
}
.fixed {
position:fixed;
top:0;
left:0;
}
#page {
height:5000px;
background:yellow;
width:100%;
}

JavaScript

$(window).scroll(function() {    
    var scroll = $(window).scrollTop();
    if (scroll >= 200) {
        $("#menu").addClass("fixed");
    } else {
        $("#menu").removeClass("fixed");
    }
});