:root {
            --primary: #4a6cf7;
            --primary-dark: #3a56d4;
            --secondary: #6c757d;
            --success: #28a745;
            --danger: #dc3545;
            --light: #f8f9fa;
            --dark: #212529;
            --border-radius: 10px;
            --box-shadow: 0 8px 20px rgba(0, 0, 0, 0.12);
            --transition: all 0.3s ease;
        }
        
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }
        
        body {
            background: linear-gradient(135deg, #f5f7ff 0%, #e6e9ff 100%);
            color: var(--dark);
            line-height: 1.6;
            padding: 20px;
            min-height: 100vh;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
        }
        
        .container {
            max-width: 900px;
            width: 100%;
            background: white;
            border-radius: var(--border-radius);
            box-shadow: var(--box-shadow);
            overflow: hidden;
            margin: 20px auto;
        }
        
        header {
            background: linear-gradient(to right, var(--primary), var(--primary-dark));
            color: white;
            padding: 25px;
            text-align: center;
        }
        
        header h1 {
            margin-bottom: 10px;
            font-size: 2.2rem;
        }
        
        header p {
            font-size: 1.1rem;
            opacity: 0.9;
        }
        
        .form-container {
            padding: 35px;
        }
        
        .form-group {
            margin-bottom: 25px;
        }
        
        label {
            display: block;
            margin-bottom: 10px;
            font-weight: 600;
            font-size: 1.05rem;
        }
        
        input, select, textarea {
            width: 100%;
            padding: 14px 18px;
            border: 1px solid #ddd;
            border-radius: var(--border-radius);
            font-size: 16px;
            transition: var(--transition);
        }
        
        input:focus, select:focus, textarea:focus {
            border-color: var(--primary);
            outline: none;
            box-shadow: 0 0 0 3px rgba(74, 108, 247, 0.2);
        }
        
        .radio-group {
            display: flex;
            flex-wrap: wrap;
            gap: 20px;
            margin-top: 10px;
        }
        
        .radio-option {
            flex: 1;
            min-width: 200px;
            border: 2px solid #e0e0e0;
            border-radius: var(--border-radius);
            padding: 20px;
            cursor: pointer;
            transition: var(--transition);
            text-align: center;
        }
        
        .radio-option:hover {
            border-color: var(--primary);
            transform: translateY(-3px);
        }
        
        .radio-option.selected {
            border-color: var(--primary);
            background-color: rgba(74, 108, 247, 0.05);
            box-shadow: 0 5px 15px rgba(74, 108, 247, 0.1);
        }
        
        .radio-option h3 {
            margin-bottom: 8px;
            color: var(--primary);
        }
        
        .radio-option .price {
            font-size: 1.4rem;
            font-weight: 700;
            color: var(--dark);
            margin: 10px 0;
        }
        
        .radio-option .description {
            font-size: 0.9rem;
            color: var(--secondary);
        }
        
        .payment-methods {
            display: flex;
            flex-wrap: wrap;
            gap: 15px;
            margin-top: 10px;
        }
        
        .payment-method {
            flex: 1;
            min-width: 150px;
            border: 2px solid #e0e0e0;
            border-radius: var(--border-radius);
            padding: 20px;
            text-align: center;
            cursor: pointer;
            transition: var(--transition);
        }
        
        .payment-method:hover {
            border-color: var(--primary);
            transform: translateY(-3px);
        }
        
        .payment-method.selected {
            border-color: var(--primary);
            background-color: rgba(74, 108, 247, 0.05);
            box-shadow: 0 5px 15px rgba(74, 108, 247, 0.1);
        }
        
        .payment-method svg {
            width: 50px;
            height: 50px;
            margin-bottom: 15px;
        }
        
        .payment-method .method-name {
            font-weight: 600;
            margin-top: 10px;
        }
        
        button {
            background: linear-gradient(to right, var(--primary), var(--primary-dark));
            color: white;
            border: none;
            padding: 18px 25px;
            border-radius: var(--border-radius);
            font-size: 18px;
            font-weight: 600;
            cursor: pointer;
            width: 100%;
            transition: var(--transition);
            margin-top: 10px;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 10px;
        }
        
        button:hover {
            transform: translateY(-3px);
            box-shadow: 0 8px 20px rgba(74, 108, 247, 0.3);
        }
        
        button:active {
            transform: translateY(0);
        }
        
        .success-page, .error-page {
            text-align: center;
            padding: 60px 30px;
        }
        
        .success-page h2, .error-page h2 {
            margin-bottom: 20px;
            font-size: 2.2rem;
        }
        
        .success-page h2 {
            color: var(--success);
        }
        
        .error-page h2 {
            color: var(--danger);
        }
        
        .success-page p, .error-page p {
            margin-bottom: 30px;
            font-size: 1.1rem;
            max-width: 600px;
            margin-left: auto;
            margin-right: auto;
        }
        
        .icon-container {
            width: 100px;
            height: 100px;
            margin: 0 auto 30px;
            display: flex;
            align-items: center;
            justify-content: center;
            border-radius: 50%;
            background-color: rgba(40, 167, 69, 0.1);
            color: var(--success);
        }
        
        .error-icon-container {
            background-color: rgba(220, 53, 69, 0.1);
            color: var(--danger);
        }
        
        .icon-container i {
            font-size: 50px;
        }
        
        .hidden {
            display: none;
        }
        
        .btn-back {
            display: inline-block;
            padding: 12px 25px;
            background: var(--primary);
            color: white;
            text-decoration: none;
            border-radius: var(--border-radius);
            font-weight: 600;
            transition: var(--transition);
            margin-top: 20px;
        }
        
        .btn-back:hover {
            background: var(--primary-dark);
            transform: translateY(-3px);
        }
        
        @media (max-width: 768px) {
            .form-container {
                padding: 25px;
            }
            
            .radio-option {
                min-width: 100%;
            }
            
            .payment-method {
                min-width: 100%;
            }
            
            header h1 {
                font-size: 1.8rem;
            }
        }
        
        .loading {
            display: none;
            text-align: center;
            padding: 30px;
        }
        
        .spinner {
            border: 5px solid #f3f3f3;
            border-top: 5px solid var(--primary);
            border-radius: 50%;
            width: 50px;
            height: 50px;
            animation: spin 1s linear infinite;
            margin: 0 auto 20px;
        }
        
        @keyframes spin {
            0% { transform: rotate(0deg); }
            100% { transform: rotate(360deg); }
        }