index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>ten</title>
    <link rel="stylesheet" href="index.css">
    <script src="https://kit.fontawesome.com/394da0ce72.js" crossorigin="anonymous"></script>
</head>
<body>
    <main>
        <label id="label">
            Make ten with…
            <p id="description">Enter four digits.</p>
            <input id="numbers" type="text" pattern="[0-9]{4}" autofocus>
        </label>
        <ul id="result"></ul>
    </main>
    <footer>
        <a href="https://github.com/sidney-pham">
            <i class="fab fa-github" title="sidney-pham"></i>
        </a>
    </footer>
    <script src="ten.js"></script>
</body>
</html>