JSFiddle - React, Tailwind, and code Playground

by spliter

HTML

<div style="height:1000px;width:500px;">
    
    <div id="floatbar" style="background:gray;
                                width:200px;
                                height:40px;
                                position:absolute;
                                left:0;top:200px;">
    </div>
</div>

JavaScript

$(window).scroll(function(){
    if ($(window).scrollTop() >= 200)
    {
        $("#floatbar").css({position:'fixed',left:'0',top:'0'});
    }
    else
    {
        $("#floatbar").css({position:'absolute',left:'0',top:'200px'});
    }
});