JSFiddle - React, Tailwind, and code Playground

HTML

<div style="height:500px;width:500;background-color:green;">
    <div id="dxy" style="width:100px; background-color:red">test</div>
</div>

JavaScript

window.onload = addListeners();

function addListeners(){
    document.getElementById('dxy').addEventListener('mousedown', mouseDown, false);
    window.addEventListener('mouseup', mouseUp, false);

}

function mouseUp()
{
    window.removeEventListener('mousemove', divMove, true);
}

function mouseDown(e){
  window.addEventListener('mousemove', divMove, true);
}

function divMove(e){
    var div = document.getElementById('dxy');
  div.style.position = 'absolute';
  div.style.top = e.clientY + 'px';
  div.style.left = e.clientX + 'px';
}