body {
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            min-height: 100vh;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            color: #333;
        }

        .container {
            padding-top: 2rem;
            padding-bottom: 2rem;
        }

        .card {
            border: none;
            border-radius: 15px;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
            backdrop-filter: blur(10px);
            background: rgba(255, 255, 255, 0.95);
        }

        .card-header {
            background: linear-gradient(135deg, #2196F3, #21CBF3);
            color: white;
            border-radius: 15px 15px 0 0 !important;
            padding: 1.5rem;
        }

        .form-control,
        .form-select {
            border-radius: 10px;
            border: 2px solid #e0e0e0;
            padding: 0.75rem 1rem;
            font-size: 1.1rem;
            transition: all 0.3s ease;
        }

        .form-control:focus,
        .form-select:focus {
            border-color: #2196F3;
            box-shadow: 0 0 0 0.2rem rgba(33, 150, 243, 0.25);
        }

        .btn-primary {
            background: linear-gradient(135deg, #2196F3, #21CBF3);
            border: none;
            border-radius: 10px;
            padding: 0.75rem 2rem;
            font-size: 1.1rem;
            font-weight: 600;
            transition: all 0.3s ease;
        }

        .btn-primary:hover {
            transform: translateY(-2px);
            box-shadow: 0 5px 15px rgba(33, 150, 243, 0.4);
        }

        .btn-info {
            background-color: #17a2b8;
            border: none;
            border-radius: 10px;
            padding: 0.75rem 1.5rem;
            font-size: 1.1rem;
            font-weight: 600;
            color: white;
            transition: all 0.3s ease;
        }

        .btn-info:hover {
            background-color: #138496;
            transform: translateY(-1px);
        }

        .btn-success {
            background-color: #28a745;
            border: none;
            border-radius: 10px;
            padding: 0.75rem 1.5rem;
            font-size: 1.1rem;
            font-weight: 600;
            color: white;
            transition: all 0.3s ease;
        }

        .btn-success:hover {
            background-color: #218838;
            transform: translateY(-1px);
        }

        .btn-outline-secondary {
            border-radius: 10px;
            padding: 0.75rem 1.5rem;
            font-size: 1.1rem;
            font-weight: 600;
            transition: all 0.3s ease;
        }

        .alert {
            border-radius: 10px;
            border: none;
        }

        .form-label {
            font-weight: 600;
            color: #495057;
            margin-bottom: 0.5rem;
        }

        .card-body {
            padding: 2rem;
        }

        .qr-code {
            display: flex;
            justify-content: center;
            align-items: center;
            padding: 10px;
            border: 1px solid #ddd;
            border-radius: 8px;
            background-color: white;
            min-height: 270px;
        }

        .qr-code canvas,
        .qr-code table {
            max-width: 100%;
            height: auto;
        }

        .spinner-border-sm {
            width: 1rem;
            height: 1rem;
        }

        .loading {
            opacity: 0.6;
            pointer-events: none;
        }

        .fixed-alert {
            position: sticky;
            top: 20px;
            z-index: 1050;
            width: 100%;
            max-width: 600px;
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
        }

        @media (max-width: 768px) {
            .container {
                padding-top: 1rem;
            }

            .card-body {
                padding: 1.5rem;
            }
        }