.payment-modal {
            position: fixed;
            inset: 0;
            background: rgba(0,0,0,0.6);
            display: none;
            align-items: center;
            justify-content: center;
            padding: 20px;
            z-index: 4000;
            backdrop-filter: blur(4px);
        }

        .payment-modal.active {
            display: flex;
        }

        .payment-modal-content {
            width: 100%;
            max-width: 520px;
            max-height: calc(100vh - 40px);
            background: #ffffff;
            border-radius: 24px;
            overflow: hidden;
            box-shadow: 0 30px 80px rgba(0,0,0,0.25);
            animation: fadeInUp 0.25s ease;
            display: flex;
            flex-direction: column;
        }

        .payment-modal-header {
            display: flex;
            align-items: center;
            justify-content: space-between;
            padding: 22px 24px;
            background: linear-gradient(135deg, var(--primary-red) 0%, var(--dark-red) 100%);
            color: var(--white);
        }

        .payment-modal-header h3 {
            font-size: 22px;
            font-weight: 700;
        }

        .payment-close {
            width: 42px;
            height: 42px;
            border: none;
            border-radius: 50%;
            background: rgba(255,255,255,0.15);
            color: var(--white);
            cursor: pointer;
            font-size: 18px;
        }

        .payment-modal-body {
            padding: 24px;
            overflow-y: auto;
            overflow-x: hidden;
            -webkit-overflow-scrolling: touch;
            flex: 1;
        }

        .payment-summary {
            background: #f8f9fa;
            border: 1px solid #ececec;
            border-radius: 16px;
            padding: 16px;
            margin-bottom: 20px;
        }

        .payment-summary strong {
            display: block;
            font-size: 17px;
            margin-bottom: 6px;
            color: var(--text-dark);
        }

        .payment-summary span {
            display: block;
            color: var(--text-gray);
            font-size: 14px;
            margin-bottom: 4px;
        }

        .payment-form-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 16px;
        }

        .payment-form-group {
            margin-bottom: 16px;
        }

        .payment-form-group.full {
            grid-column: 1 / -1;
        }

        .payment-form-group label {
            display: block;
            margin-bottom: 8px;
            font-size: 14px;
            font-weight: 600;
            color: var(--text-dark);
        }

        .payment-form-group input {
            width: 100%;
            padding: 14px 16px;
            border: 2px solid #e6e6e6;
            border-radius: 12px;
            font-size: 15px;
            color: var(--text-dark);
            background: #fff;
            transition: all 0.3s ease;
        }

        .payment-form-group input:focus {
            outline: none;
            border-color: var(--primary-red);
            box-shadow: 0 0 0 4px rgba(227, 6, 19, 0.08);
        }

        .payment-secure-note {
            margin-top: 8px;
            font-size: 13px;
            color: var(--text-gray);
            display: flex;
            align-items: center;
            gap: 8px;
        }

        .payment-secure-note i {
            color: #28a745;
        }

        .payment-action-bar {
            position: sticky;
            bottom: 0;
            margin-top: 18px;
            padding-top: 14px;
            background: linear-gradient(to top, #ffffff 78%, rgba(255,255,255,0.92) 100%);
        }

        .payment-submit {
            width: 100%;
            margin-top: 0;
            padding: 16px;
            border: none;
            border-radius: 14px;
            background: linear-gradient(135deg, var(--primary-red) 0%, var(--dark-red) 100%);
            color: var(--white);
            font-size: 16px;
            font-weight: 700;
            cursor: pointer;
            transition: all 0.3s ease;
        }

        .payment-submit:hover {
            transform: translateY(-2px);
            box-shadow: 0 14px 30px rgba(227, 6, 19, 0.25);
        }

        @media (max-width: 768px) {
            .payment-modal {
                padding: 0;
                align-items: flex-end;
            }
            .payment-modal-content {
                max-width: 100%;
                max-height: 88vh;
                border-radius: 24px 24px 0 0;
            }
            .payment-modal-header { padding: 18px; }
            .payment-modal-header h3 { font-size: 18px; }
            .payment-modal-body {
                padding: 18px;
            }
            .payment-form-grid { grid-template-columns: 1fr; gap: 0; }
            .payment-action-bar {
                margin-top: 14px;
                padding-bottom: calc(env(safe-area-inset-bottom, 0px) + 6px);
            }
        }