W3Schools Tryit Editor

<!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>Disabled Buttons (w3-button)</h2>
  
  <p>Link buttons:</p>
  <a class="w3-button w3-black" href="#">Link Button</a>  
  <a class="w3-button w3-black w3-disabled" href="#">Link Button</a>
  
  <p>Button buttons:</p>  
  <button class="w3-button w3-teal">Button</button>
  <button class="w3-button w3-teal" disabled>Button</button>
  
  <p>Input buttons:</p>    
  <input type="button" class="w3-button w3-red" value="Input Button">
  <input type="button" class="w3-button w3-red" value="Input Button" disabled>

<h2>Disabled Buttons (w3-btn)</h2>
  
  <p>Link buttons:</p>
  <a class="w3-btn w3-black" href="#">Link Button</a>  
  <a class="w3-btn w3-black w3-disabled" href="#">Link Button</a>
  
  <p>Button buttons:</p>  
  <button class="w3-btn w3-teal">Button</button>
  <button class="w3-btn w3-teal" disabled>Button</button>
  
  <p>Input buttons:</p>    
  <input type="button" class="w3-btn w3-red" value="Input Button">
  <input type="button" class="w3-btn w3-red" value="Input Button" disabled>
</div>

</body>
</html>