JSFiddle - React, Tailwind, and code Playground

HTML

<div id="box">
    <div id="results">
        <span id="pageX"></span>
        <span id="pageY"></span>
    </div>
    <div id="inner-box"></div>
    <div id="followMouse">*</div>
</div>

CSS

#box {
    height:1000px;
    position:relative;
}
#inner-box 
{
     width:400px;
     height:400px;
    background-color:Red;    
    margin-top:500px;
} 

#followMouse {
    position:absolute;
}

#results { position:fixed; top:0px; }

JavaScript

$("#inner-box").on("mousemove", function(evt) {
    var offset = $("#inner-box").offset();
    $("#followMouse").show()
        .css("left", evt.pageX - offset.left + 10 + "px")
        .css("top", evt.pageY - offset.top - 10 + "px");
});