JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://ajax.googleapis.com/ajax/libs/prototype/1.7.3.0/prototype.js"></script>

JavaScript

var dblCtrlKey = 0;
Event.observe(document, 'keydown', function(event) {
  if (dblCtrlKey != 0 && event.ctrlKey) {
    alert("Ok double ctrl");
    dblCtrlKey = 0;
  } else {
    dblCtrlKey = setTimeout('dblCtrlKey = 0;', 300);
  }
});