404.html

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Page not found - 404</title>
</head>

<body>
    <style>
        * {
            margin: 0;
            padding: 0;
        }

        body {
            text-align: center;
            background-color: #ccc;
            font-family: sans-serif;
            color: #000;
        }

        a {
            text-decoration: none;
            color: dodgerblue;
        }

        h1 {
            font-size: 120px;
        }

        h4 {
            margin-bottom: 2em;
        }
    </style>
    <h1>404</h1>
    <h4>Sorry, but this page not found.</h4>
    <a href="/">Back to home</a>
</body>

</html>