/* Centered container with soft shadow */
        .container {
            max-width: 500px;
            background: #fff;
            padding: 30px;
            border-radius: 12px;
            box-shadow: 0px 8px 20px rgba(0, 0, 0, 0.1);
            text-align: center;
            transition: 0.3s;
        }

        .container:hover {
            transform: scale(1.02);
            box-shadow: 0px 10px 25px rgba(0, 0, 0, 0.15);
        }

        h1 {
            color: #444;
            font-weight: bold;
            margin-bottom: 20px;
        }

        label {
            font-weight: bold;
            margin-bottom: 5px;
            color: #666;
        }

        input[type="text"] {
            width: 100%;
            padding: 12px;
            border: 2px solid #ddd;
            border-radius: 8px;
            font-size: 16px;
            transition: 0.3s;
        }

        input[type="text"]:focus {
            border-color: #4CAF50;
            outline: none;
            box-shadow: 0px 0px 5px rgba(76, 175, 80, 0.5);
        }

        .btn {
            width: 100%;
            padding: 12px;
            border-radius: 8px;
            font-size: 16px;
            font-weight: bold;
            transition: 0.3s;
        }

        .btn-primary {
            background: #007bff;
            border: none;
        }

        .btn-primary:hover {
            background: #0056b3;
        }

        .btn-success {
            margin-top: 10px;
            background: #28a745;
            border: none;
        }

        .btn-success:hover {
            background: #218838;
        }

        /* Dark Mode */
        body.dark-mode {
            background-color: #121212;
            color: white;
        }

        .dark-mode .container {
            background: #222;
            box-shadow: 0px 8px 20px rgba(255, 255, 255, 0.1);
        }

        .dark-mode h1 {
            color: #ddd;
        }

        .dark-mode label {
            color: #bbb;
        }

        .dark-mode input[type="text"] {
            background: #333;
            color: white;
            border: 2px solid #555;
        }

        .dark-mode .btn-primary {
            background: #5cb85c;
        }

        .dark-mode .btn-primary:hover {
            background: #4cae4c;
        }

        .dark-mode .btn-success {
            background: #17a2b8;
        }

        .dark-mode .btn-success:hover {
            background: #138496;
        }

        /* Dark Mode Toggle */
        .dark-mode-switch {
            position: fixed;
            top: 15px;
            right: 15px;
        }

        /* Responsive */
        @media (max-width: 600px) {
            .container {
                padding: 20px;
            }
        }