<!DOCTYPE html>
<html>
<head>
    <title>Invalid Request</title>
    <style>
        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
            display: flex;
            justify-content: center;
            align-items: center;
            height: 100vh;
            margin: 0;
            background-color: #f5f5f5;
        }
        .container {
            text-align: center;
            padding: 40px;
            background: white;
            border-radius: 8px;
            box-shadow: 0 2px 10px rgba(0,0,0,0.1);
            max-width: 500px;
        }
        h1 {
            color: #ff9800;
            margin-bottom: 20px;
        }
        p {
            color: #666;
        }
    </style>
</head>
<body>
    <div class="container">
        <h1>⚠️ Invalid Request</h1>
        <p>This doesn't appear to be a valid authentication callback.</p>
        <p>Please close this tab and try the authentication process again.</p>
    </div>
</body>
</html>
