JSFiddle - React, Tailwind, and code Playground

HTML

<div id="content">
    SYDNEY (Reuters) - An Australian man had his driving licence suspended for 10 months and was fined after he was caught driving a scooter made of a motorised beer cooler capable of carrying several dozen drinks -- after knocking back a few.
</div>
<div id="output">   
    
</div>    
<div id="onTop">
    <!-- I'm always on top -->
</div>

CSS

#content {
    background-color:#cccc99;    
}

#onTop {
    position:absolute;
    width: 100px;
    height: 50px;
    left: 100px;
    top: 10px;
    background-color: #cccccc;
}

JavaScript

$(function() {
    var output = $("#output");
    var content = $("#content");
    var eventSource = $("<div></div>");
    $("body").append(eventSource);
    
    eventSource.css({
        position: "absolute",
        left: content.offset().left,
        top: content.offset().top,
        width: content.width(),
        height: content.height(),
        opacity: 0,
        "z-index": 999,
    }).mouseenter(function(e){
        output.text("I'm in!");
    }).mouseout(function(e) {
        output.text("I'm out!"); 
    });
});