JSFiddle - React, Tailwind, and code Playground

HTML

<button>Button 1</button>
<button id="btn">Another button</button>

CSS

button {
    background: #666;
    border: 0;
    border-radius: 5px;
    color: #fff;
    padding: 5px;
    width: 200px;
}

JavaScript

document.getElementById('btn').textContent = 'New text with big content';