<!-- add it to the head section of the html file -->
<link href="https://unpkg.com/tailwindcss@^1.0/dist/tailwind.min.css"
rel="stylesheet"><!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 class="text-3xl font-bold underline">
Hello world!
</h1>
</body>
</html>