JSFiddle - React, Tailwind, and code Playground

HTML

<div id="cellValueEditorDiv"></div>

CSS

#cellValueEditorDiv {
    width: 500px;
    height: 500px;
    background-color: #F00;
}

JavaScript

function mouseCords(e) {
    alert(e.offsetX + " " + e.offsetY);
}

document.getElementById("cellValueEditorDiv").addEventListener("click", mouseCords, false);