offline.html

<!DOCTYPE html>
<html>

<head>
    <meta charset="UTF-8">
    <title>Node Template</title>
    <style>
        * {
            margin: 0;
            padding: 0;
        }

        div {
            align-items: center;
            background: #000;
            box-sizing: border-box;
            color: #fff;
            cursor: default;
            display: flex;
            font-family: 'Arial';
            font-size: 1.6rem;
            height: 100%;
            justify-content: center;
            left: 0;
            padding: 4rem;
            position: fixed;
            text-align: center;
            top: 0;
            width: 100%;
            z-index: 4;
        }
    </style>
</head>

<body>
    <div>
        <p>
            This experience is only available with internet connection.
        </p>
    </div>
</body>

</html>