JSFiddle - React, Tailwind, and code Playground

HTML

<div class="modalOverlay" id="modal" onkeydown="hideModalKeyPress(e);">Press ESC to hide me.</div>

/*
 * I want to set the div's visibility to hidden
 * when user presses ESC key
*/

CSS

.modalOverlay
{
  width: 200px;
  height: 200px;
  opacity: 0.8;
  background-color: black;
  visibility: visible;
}

JavaScript

document.onkeydown = function(evt) {
    evt = evt || window.event;
    if (evt.keyCode == 27) {
        document.getElementById("modal").style.visibility = "hidden";
    }
};