:root {
            --black: #000000;
            --white: #ffffff;
            --light-gray: #f5f5f5;
            --medium-gray: #e0e0e0;
            --dark-gray: #333333;
            --transition: all 0.4s cubic-bezier(0.25, 0.8, 0.25, 1);
        }

        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        body {
            font-family: 'Montserrat', sans-serif;
            color: var(--black);
            background-color: var(--white);
            line-height: 1.6;
            overflow-x: hidden;
        }

        h1, h2, h3, h4 {
            font-family: 'Playfair Display', serif;
            font-weight: 600;
            letter-spacing: 0.5px;
        }

        .container {
            width: 95%;
            max-width: 1200px;
            margin: 150px auto 100px;
            padding: 0 20px;
        }

        .payment-header {
            text-align: center;
            margin-bottom: 50px;
        }

        .payment-header h1 {
            font-size: 32px;
            margin-bottom: 15px;
            position: relative;
            display: inline-block;
        }

        .payment-header h1::after {
            content: '';
            position: absolute;
            bottom: -10px;
            left: 50%;
            transform: translateX(-50%);
            width: 80px;
            height: 2px;
            background: var(--black);
        }

        .payment-header p {
            font-size: 14px;
            color: var(--dark-gray);
            max-width: 600px;
            margin: 0 auto;
        }

        .payment-container {
            display: flex;
            gap: 40px;
            flex-wrap: wrap;
        }

        .payment-form-container {
            flex: 1;
            min-width: 300px;
        }

        .payment-summary {
            flex: 0 0 350px;
            background: var(--light-gray);
            padding: 30px;
            border-radius: 0;
        }

        .payment-card {
            background: var(--white);
            border: 1px solid var(--medium-gray);
            border-radius: 0;
            padding: 30px;
            box-shadow: 0 5px 30px rgba(0, 0, 0, 0.05);
            margin-bottom: 30px;
        }

        .payment-card-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 25px;
        }

        .payment-card-header h3 {
            font-size: 18px;
            font-weight: 600;
        }

        .payment-protection {
            display: flex;
            align-items: center;
            gap: 10px;
            font-size: 12px;
            color: var(--dark-gray);
        }

        .payment-protection i {
            color: var(--black);
        }

        .card-icons {
            display: flex;
            gap: 10px;
            margin-bottom: 20px;
        }

        .card-icons img {
            height: 30px;
            filter: grayscale(100%);
            opacity: 0.5;
            transition: var(--transition);
            border-radius: 0;
        }

        .card-icons img.active {
            filter: grayscale(0);
            opacity: 1;
        }

        .form-group {
            margin-bottom: 20px;
            position: relative;
        }

        .form-group label {
            display: block;
            margin-bottom: 8px;
            font-size: 13px;
            font-weight: 500;
            text-transform: uppercase;
            letter-spacing: 1px;
            color: var(--dark-gray);
        }

        .form-control {
            width: 100%;
            padding: 12px 15px;
            border: 1px solid var(--medium-gray);
            border-radius: 0;
            font-size: 15px;
            transition: var(--transition);
            background-color: var(--white);
            color: var(--black);
        }

        .form-control:focus {
            outline: none;
            border-color: var(--black);
            box-shadow: 0 0 0 1px var(--black);
        }

        .form-control.error {
            border-color: var(--black);
        }

        .error-message {
            color: var(--black);
            font-size: 12px;
            margin-top: 5px;
            display: none;
            font-weight: 500;
        }

        .form-row {
            display: flex;
            gap: 20px;
        }

        .form-row .form-group {
            flex: 1;
        }

        .cvv-info {
            position: absolute;
            top: 0;
            right: 0;
            cursor: help;
        }

        .cvv-info i {
            color: var(--dark-gray);
            font-size: 16px;
        }

        .cvv-tooltip {
            position: absolute;
            top: 100%;
            right: 0;
            background: var(--black);
            color: var(--white);
            padding: 10px;
            font-size: 12px;
            border-radius: 0;
            width: 200px;
            z-index: 10;
            display: none;
        }

        .cvv-info:hover .cvv-tooltip {
            display: block;
        }

        .save-card {
            display: flex;
            align-items: center;
            gap: 10px;
            margin: 25px 0;
            font-size: 14px;
        }

        .save-card input {
            accent-color: var(--black);
        }

        .btn-pay {
            width: 100%;
            padding: 15px;
            background: var(--black);
            color: var(--white);
            border: none;
            border-radius: 0;
            font-size: 16px;
            font-weight: 600;
            cursor: pointer;
            transition: var(--transition);
            text-transform: uppercase;
            letter-spacing: 1px;
        }

        .btn-pay:hover {
            background: var(--dark-gray);
            transform: translateY(-2px);
        }

        .btn-pay:disabled {
            background: var(--medium-gray);
            cursor: not-allowed;
            transform: none;
        }

        .payment-summary h3 {
            font-size: 18px;
            margin-bottom: 25px;
            padding-bottom: 15px;
            border-bottom: 1px solid var(--medium-gray);
        }

        .summary-item {
            display: flex;
            justify-content: space-between;
            margin-bottom: 15px;
            font-size: 14px;
        }

        .summary-total {
            font-weight: 600;
            font-size: 16px;
            margin: 25px 0;
            padding-top: 15px;
            border-top: 1px solid var(--medium-gray);
        }

        .secure-payment {
            display: flex;
            align-items: center;
            gap: 10px;
            font-size: 12px;
            color: var(--dark-gray);
            margin-top: 30px;
        }

        .secure-payment i {
            color: var(--black);
            font-size: 16px;
        }

        /* Credit Card Preview */
        .card-preview {
            background: linear-gradient(135deg, #333333, #000000);
            color: white;
            border-radius: 0;
            padding: 20px;
            margin-bottom: 30px;
            height: 200px;
            display: flex;
            flex-direction: column;
            justify-content: space-between;
            box-shadow: 0 10px 20px rgba(0, 0, 0, 0.2);
            transition: var(--transition);
            position: relative;
            overflow: hidden;
        }

        .card-preview::before {
            content: '';
            position: absolute;
            top: -50%;
            right: -50%;
            width: 200px;
            height: 200px;
            background: radial-gradient(circle, rgba(255, 255, 255, 0.1) 0%, rgba(255, 255, 255, 0) 70%);
            border-radius: 0;
        }

        .card-preview .card-logo {
            text-align: right;
            font-size: 24px;
            font-weight: bold;
            opacity: 0.8;
        }

        .card-preview .card-number {
            font-size: 20px;
            letter-spacing: 2px;
            font-family: 'Courier New', monospace;
            margin: 20px 0;
            word-spacing: 8px;
        }

        .card-preview .card-details {
            display: flex;
            justify-content: space-between;
            font-size: 14px;
            opacity: 0.8;
        }

        .card-preview .card-name {
            text-transform: uppercase;
        }

        .card-preview .card-expiry {
            text-align: right;
        }

        /* Responsive */
        @media (max-width: 768px) {
            .container {
                margin-top: 120px;
            }
            
            .payment-container {
                flex-direction: column;
            }
            
            .payment-summary {
                order: -1;
            }
            
            .form-row {
                flex-direction: column;
                gap: 0;
            }
        }