<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1">
<link href='app.css' rel='stylesheet'>
<script src='crypto.js'></script>
<script src='app.js'></script>
</head>
<body>
<main>
<h1>Secret Message Machine</h1>
<input placeholder='Enter a key'>
<section>
<textarea placeholder='Enter a message to encrypt'></textarea>
<button>Encrypt</button>
</section>
<section>
<textarea placeholder='Enter a message to decrypy'></textarea>
<button>Decrypt</button>
</section>
</main>
</body>
</html>