<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<script src="https://cdn.tailwindcss.com"></script>
</head>
<body>
<h1>Hello world!</h1>
<h1 class="text-3xl font-bold underline">Hello world!</h1>
</body>
</html>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<script src="https://cdn.tailwindcss.com"></script>
</head>
<body>
<h1>Hello world!</h1>
<h1 class="text-3xl font-bold underline">Hello world!</h1>
</body>
</html>