<!DOCTYPE html>
<html>
<title>W3.CSS</title>
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://www.w3schools.com/w3css/4/w3.css">
<body>
<div class="w3-container">
<h2>Button Bars</h2>
<p>The size of each items can be defined by using <strong>style="width:"</strong>:</p>
<div class="w3-bar">
<button class="w3-bar-item w3-button w3-black" style="width:33.3%">Button</button>
<button class="w3-bar-item w3-button w3-teal" style="width:33.3%">Button</button>
<button class="w3-bar-item w3-button w3-red" style="width:33.3%">Button</button>
</div>
</div>
</body>
</html>