JSFiddle - React, Tailwind, and code Playground

by Gustavo Rodrigues

HTML

<div class="item"></div>
<div class="item"></div>
<div class="item"></div>
<div class="item"></div>
<div class="item"></div>
<button onclick="changeBG()">
  Change BG
</button>

CSS

.item { 
width: 50px;
height: 50px;
background: green;
margin-right: 10px;
margin-top: 10px;
}
button { margin-top: 20px; }

JavaScript

window.changeBG = function() { 
	var items = document.getElementsByClassName('item');
  for(var i in items) items[i].style.backgroundColor = 'red'; 
}