JSFiddle - React, Tailwind, and code Playground

HTML

<div class="side">
<div id="follower"><a href="#">hello</a></div>
</div>

CSS

.side {
    
    background-color: green;
    height: 800px;
    width:100px;
    margin:50px;
}


#follower{
  position : absolute;
  background-color : red;
  color : white;
  padding : 10px;
}

JavaScript

var mouseX = 0, mouseY = 0;
$(".side").mousemove(function(e){
   mouseY = e.clientY-19; 
   follower.html(mouseY);
});

// cache the selector
var follower = $("#follower");
yp = 0;
var loop = setInterval(function(){

    yp += (mouseY - yp) / 6;
    follower.css({top:yp});
    
}, 10);