JSFiddle - React, Tailwind, and code Playground

HTML

<button id="trigger" class="btn primary">Open modal</button>
<div id="theModal" class="cd-box modal bg">
  <div class=card>
    <div class="title">
      <h3>Title</h3>
    </div>
    <div class="close"></div>
    <div class="inside">
      <p>This is some content that goes into the modal. The width adjusts according to the content.</p>
    </div>
    <div class="buttons">
      <button id="exit" class="btn secondary">Exit</button>
      <button class="btn primary">Continue with action</button>
    </div>
  </div>
</div>

JavaScript

var modal = document.getElementById("theModal");
var btn = document.getElementById("trigger");
var exit = document.getElementById("exit");
var span = document.getElementsByClassName("close")[0];
btn.onclick = function () {
	modal.style.display = "block";
}
exit.onclick = function () {
	modal.style.display = "none";
}
window.onclick = function (event) {
	console.log(event)
	if (event.target == modal) {
  	modal.style.display = "none";
  }
}