JSFiddle - React, Tailwind, and code Playground

HTML

<div class="block"></div>
<div class="block"></div>
<div class="block"></div>
<div class="block"></div>
<div class="block"></div>

CSS

.block {
  width: 100px;
  height: 50px;
  margin: 5px;
  background: blue;
  cursor: pointer;
}

.block--active {
  background-color: red;
}

JavaScript

document.addEventListener('click', (e) => {
	if (!e.target.classList.contains('block')) return;
  const elem = document.querySelector('.block.block--active');
  if (elem) elem.classList.remove('block--active');
  e.target.classList.add('block--active');
});