/* ========== 全站共用变量 ========== */
        :root {
            --primary-blue: #0b2545;
            --accent-blue: #134074;
            --light-blue: #8da9c4;
            --dark-charcoal: #1d2d44;
            --pure-white: #ffffff;
            --border-color: #e2e8f0;
            --text-main: #334155;
            --alert-red: #d9383a;
            --xnair-accent: #0b2545;
            --xnair-soft-bg: #f8fafc;
            --xnair-card-shadow: 0 2px 12px rgba(0, 0, 0, 0.06);
            --xnair-table-stripe: #f1f5f9;
            --xnair-highlight: #e6f5ff;
            --xnair-cta: #d9383a;
            --xnair-cta-hover: #b82d2f;
            --xnair-green: #16a34a;
            --xnair-amber: #d97706;
        }

        /* ========== 全局基础重置 ========== */
        * {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
        }
        body {
            font-family: "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
            color: var(--text-main);
            background-color: var(--pure-white);
            line-height: 1.6;
            font-size: 16px;
            -webkit-font-smoothing: antialiased;
        }
        img {
            max-width: 100%;
            height: auto;
            display: block;
        }
        a {
            text-decoration: none;
            color: inherit;
            transition: all 0.3s ease;
        }

        /* ========== 全局容器 ========== */
        .container {
            width: 100%;
            max-width: 1440px;
            margin: 0 auto;
            padding: 0 40px;
        }

        /* ========== 顶部信息条 top-bar ========== */
        .top-bar {
            background-color: var(--primary-blue);
            color: var(--pure-white);
            font-size: 14px;
            padding: 12px 0;
            border-bottom: 1px solid rgba(255, 255, 255, 0.1);
        }
        .top-bar-flex {
            display: flex;
            justify-content: space-between;
            align-items: center;
        }

        /* ========== Header 导航 ========== */
        header {
            background: var(--pure-white);
            border-bottom: 1px solid var(--border-color);
            position: sticky;
            top: 0;
            z-index: 1000;
            box-shadow: 0 4px 20px rgba(0, 0, 0, 0.04);
        }
        .header-flex {
            display: flex;
            justify-content: space-between;
            align-items: center;
            height: 80px;
            max-width: 100%;
            padding: 0 12%;
            margin: 0 auto;
            background: #fff;
        }
        .logo-area img {
            height: 55px;
            object-fit: contain;
        }
        nav ul {
            list-style: none;
            display: flex;
            gap: 20px;
        }
        nav ul li a {
            font-size: 16px;
            font-weight: 600;
            color: var(--dark-charcoal);
            padding: 8px 4px;
            letter-spacing: 0.5px;
        }
        nav ul li a:hover,
        nav ul li a.active {
            color: #3399ff;
            background-color: #e6f5ff;
            border-bottom: 6px solid #3399ff;
        }

        /* ========== 汉堡菜单 ========== */
        .menu-toggle {
            display: none;
            font-size: 28px;
            cursor: pointer;
            color: var(--dark-charcoal);
            padding: 8px;
            flex-shrink: 0;
        }

        /* ========== 移动端768px适配 ========== */
        @media(max-width: 768px) {
            .container {
                padding: 0 20px;
            }
            .header-flex {
                position: relative;
                flex-wrap: wrap;
                flex-direction: row !important;
                justify-content: space-between;
                align-items: center;
            }
            .menu-toggle {
                display: block;
                order: 2;
            }
            .logo-area {
                order: 1;
            }
            header nav {
                width: 100%;
                position: absolute;
                left: 0;
                top: 100%;
                background: #fff;
                box-shadow: 0 8px 15px rgba(0, 0, 0, 0.08);
                max-height: 0;
                overflow: hidden;
                transition: max-height 0.35s ease;
                order: 3;
            }
            header nav.open {
                max-height: 600px;
            }
            nav ul {
                flex-direction: column;
                padding: 15px 20px;
                gap: 8px !important;
            }
            nav ul li a {
                display: block;
                padding: 10px 0;
                text-align: center;
            }
            .top-bar-flex {
                flex-direction: column;
                text-align: center;
                gap: 15px;
            }
        }

        /* ========== footer底部样式 ========== */
        footer {
            background-color: #2c2f38;
            color: #e2e8f0;
            padding: 50px 0 30px;
        }
        .footer-row {
            display: grid;
            grid-template-columns: 1fr 1fr 1fr 1fr 1fr;
            gap: 30px;
            margin-bottom: 35px;
        }
        .footer-contact-item {
            display: flex;
            align-items: flex-start;
            gap: 14px;
            margin-bottom: 22px;
        }
        .footer-contact-icon {
            width: 50px;
            height: 50px;
            border-radius: 50%;
            background: #444750;
            display: flex;
            align-items: center;
            justify-content: center;
            flex-shrink: 0;
            font-size: 24px;
        }
        .footer-col h5 {
            font-size: 22px;
            margin-bottom: 20px;
            font-weight: 600;
            color: #fff;
        }
        .footer-col ul {
            list-style: none;
        }
        .footer-col ul li {
            margin-bottom: 10px;
            font-size: 16px;
        }
        .footer-col ul li a:hover {
            color: #8da9c4;
        }
        .footer-bottom-text {
            text-align: center;
            padding-top: 25px;
            border-top: 1px solid #444750;
            font-size: 17px;
            color: #b0b8c4;
        }
        .footer-contact-text a {
            font-size: 20px;
            font-weight: 500;
            color: #fff;
        }
        @media(max-width: 1200px) {
            .footer-row {
                grid-template-columns: repeat(3, 1fr);
                gap: 25px;
            }
        }
        @media(max-width: 768px) {
            .footer-row {
                grid-template-columns: 1fr;
            }
        }

        /* ================================================================
           产品页面专属CSS（xnair- 命名空间，与头部底部零冲突）
           ================================================================ */
        /* -- 面包屑导航 -- */
        .xnair-breadcrumb {
            background: var(--xnair-soft-bg);
            padding: 14px 0;
            font-size: 14px;
            color: #64748b;
            border-bottom: 1px solid var(--border-color);
        }
        .xnair-breadcrumb .container {
            display: flex;
            align-items: center;
            flex-wrap: wrap;
            gap: 6px;
        }
        .xnair-breadcrumb a {
            color: var(--accent-blue);
            font-weight: 500;
        }
        .xnair-breadcrumb a:hover {
            color: #3399ff;
            text-decoration: underline;
        }
        .xnair-breadcrumb .xnair-sep {
            color: #94a3b8;
            margin: 0 4px;
            user-select: none;
        }
        .xnair-breadcrumb .xnair-current {
            color: var(--text-main);
            font-weight: 600;
        }

        /* -- Hero 区域 -- */
        .xnair-hero-wrap {
            background: #fff;
            padding: 48px 0 40px;
        }
        .xnair-hero-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 48px;
            align-items: center;
        }
        .xnair-hero-content h1 {
            font-size: 2rem;
            font-weight: 700;
            color: var(--dark-charcoal);
            line-height: 1.3;
            margin-bottom: 16px;
            letter-spacing: -0.3px;
        }
        .xnair-hero-content .xnair-hero-subtitle {
            font-size: 17px;
            color: #475569;
            margin-bottom: 20px;
            line-height: 1.55;
        }
        .xnair-hero-badges {
            display: flex;
            flex-wrap: wrap;
            gap: 12px;
            margin-bottom: 20px;
        }
        .xnair-hero-badge {
            display: inline-flex;
            align-items: center;
            gap: 6px;
            background: var(--xnair-highlight);
            color: var(--accent-blue);
            font-size: 13px;
            font-weight: 600;
            padding: 8px 14px;
            border-radius: 6px;
            white-space: nowrap;
        }
        .xnair-hero-image {
            position: relative;
            border-radius: 12px;
            overflow: hidden;
            box-shadow: var(--xnair-card-shadow);
            background: #f1f5f9;
        }
        .xnair-hero-image img {
            width: 100%;
            height: auto;
            aspect-ratio: 4/3;
        }
        .xnair-hero-cta-row {
            display: flex;
            flex-wrap: wrap;
            gap: 14px;
            margin-top: 8px;
        }
        .xnair-btn-primary {
            display: inline-block;
            background: var(--xnair-cta);
            color: #fff;
            font-weight: 700;
            font-size: 15px;
            padding: 14px 28px;
            border-radius: 8px;
            letter-spacing: 0.3px;
            transition: background 0.25s ease, transform 0.15s ease;
            cursor: pointer;
            border: none;
            text-align: center;
        }
        .xnair-btn-primary:hover {
            background: var(--xnair-cta-hover);
            transform: translateY(-1px);
        }
        .xnair-btn-outline {
            display: inline-block;
            background: #fff;
            color: var(--accent-blue);
            font-weight: 600;
            font-size: 15px;
            padding: 14px 28px;
            border-radius: 8px;
            border: 2px solid var(--accent-blue);
            letter-spacing: 0.3px;
            transition: all 0.25s ease;
            cursor: pointer;
            text-align: center;
        }
        .xnair-btn-outline:hover {
            background: var(--xnair-highlight);
            border-color: #3399ff;
            color: #3399ff;
        }

        /* -- 主内容区布局（桌面端：TOC侧边栏 + 内容） -- */
        .xnair-main-layout {
            display: grid;
            grid-template-columns: 260px 1fr;
            gap: 40px;
            padding: 40px 0 50px;
            align-items: start;
        }

        /* -- TOC 悬浮目录 -- */
        .xnair-toc-wrap {
            position: sticky;
            top: 100px;
            background: #fff;
            border: 1px solid var(--border-color);
            border-radius: 10px;
            padding: 20px 18px;
            box-shadow: var(--xnair-card-shadow);
            max-height: calc(100vh - 140px);
            overflow-y: auto;
        }
        .xnair-toc-wrap .xnair-toc-title {
            font-size: 15px;
            font-weight: 700;
            color: var(--dark-charcoal);
            margin-bottom: 14px;
            text-transform: uppercase;
            letter-spacing: 0.8px;
            padding-bottom: 10px;
            border-bottom: 2px solid var(--border-color);
        }
        .xnair-toc-wrap ul {
            list-style: none;
            display: flex;
            flex-direction: column;
            gap: 6px;
        }
        .xnair-toc-wrap ul li a {
            display: block;
            font-size: 14px;
            color: #475569;
            padding: 7px 10px;
            border-radius: 5px;
            font-weight: 500;
            line-height: 1.4;
            transition: all 0.2s ease;
        }
        .xnair-toc-wrap ul li a:hover,
        .xnair-toc-wrap ul li a.xnair-toc-active {
            background: var(--xnair-highlight);
            color: #3399ff;
            font-weight: 600;
        }
        .xnair-toc-mobile-toggle {
            display: none;
            width: 100%;
            background: var(--xnair-soft-bg);
            border: 1px solid var(--border-color);
            border-radius: 8px;
            padding: 12px 16px;
            font-size: 15px;
            font-weight: 600;
            color: var(--dark-charcoal);
            cursor: pointer;
            text-align: left;
            margin-bottom: 16px;
        }
        .xnair-toc-mobile-toggle::after {
            content: ' ▾';
            float: right;
            transition: transform 0.3s ease;
        }
        .xnair-toc-mobile-toggle.xnair-open::after {
            transform: rotate(180deg);
        }
        .xnair-toc-mobile-panel {
            display: none;
            background: #fff;
            border: 1px solid var(--border-color);
            border-radius: 8px;
            padding: 14px 16px;
            margin-bottom: 20px;
            box-shadow: var(--xnair-card-shadow);
        }
        .xnair-toc-mobile-panel.xnair-visible {
            display: block;
        }
        .xnair-toc-mobile-panel ul {
            list-style: none;
            display: flex;
            flex-direction: column;
            gap: 4px;
        }
        .xnair-toc-mobile-panel ul li a {
            display: block;
            font-size: 14px;
            color: #475569;
            padding: 8px 10px;
            border-radius: 5px;
            font-weight: 500;
        }

        /* -- 内容区通用样式 -- */
        .xnair-content-area h2 {
            font-size: 1.6rem;
            font-weight: 700;
            color: var(--dark-charcoal);
            margin-bottom: 14px;
            padding-bottom: 10px;
            border-bottom: 3px solid var(--accent-blue);
            letter-spacing: -0.2px;
        }
        .xnair-content-area h3 {
            font-size: 1.2rem;
            font-weight: 700;
            color: var(--dark-charcoal);
            margin-bottom: 10px;
            margin-top: 22px;
        }
        .xnair-content-area p {
            margin-bottom: 14px;
            color: #475569;
            line-height: 1.7;
        }
        .xnair-content-area ul,
        .xnair-content-area ol {
            margin-bottom: 16px;
            padding-left: 22px;
            color: #475569;
        }
        .xnair-content-area ul li,
        .xnair-content-area ol li {
            margin-bottom: 8px;
            line-height: 1.6;
        }
        .xnair-section {
            margin-bottom: 44px;
            scroll-margin-top: 100px;
        }

        /* -- AI Overview 摘要卡片 -- */
        .xnair-overview-card {
            background: var(--xnair-soft-bg);
            border-left: 5px solid var(--accent-blue);
            padding: 22px 24px;
            border-radius: 0 10px 10px 0;
            margin-bottom: 32px;
        }
        .xnair-overview-card p {
            margin-bottom: 0;
            font-size: 15px;
            color: var(--dark-charcoal);
            font-weight: 500;
            line-height: 1.7;
        }

        /* -- 技术参数表格 -- */
        .xnair-specs-table-wrap {
            overflow-x: auto;
            -webkit-overflow-scrolling: touch;
            margin-bottom: 20px;
        }
        .xnair-specs-table {
            width: 100%;
            border-collapse: collapse;
            font-size: 14px;
            min-width: 640px;
        }
        .xnair-specs-table thead th {
            background: var(--accent-blue);
            color: #fff;
            padding: 14px 16px;
            text-align: left;
            font-weight: 600;
            font-size: 13px;
            text-transform: uppercase;
            letter-spacing: 0.5px;
            white-space: nowrap;
        }
        .xnair-specs-table tbody td {
            padding: 12px 16px;
            border-bottom: 1px solid var(--border-color);
            vertical-align: top;
        }
        .xnair-specs-table tbody tr:nth-child(even) td {
            background: var(--xnair-table-stripe);
        }
        .xnair-specs-table tbody tr:hover td {
            background: var(--xnair-highlight);
        }
        .xnair-specs-table .xnair-param-label {
            font-weight: 700;
            color: var(--dark-charcoal);
            white-space: nowrap;
        }

        /* -- 图片通用样式 -- */
        .xnair-figure {
            margin: 24px 0;
            border-radius: 10px;
            overflow: hidden;
            box-shadow: var(--xnair-card-shadow);
            background: #f8fafc;
        }
        .xnair-figure img {
            width: 100%;
            height: auto;
            display: block;
            aspect-ratio: 16/10;
        }
        .xnair-figure figcaption {
            padding: 12px 16px;
            font-size: 13px;
            color: #64748b;
            background: #fff;
            font-style: italic;
            border-top: 1px solid var(--border-color);
        }
        .xnair-img-row {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 24px;
            margin: 20px 0;
        }

        /* -- 全球适应性卡片 -- */
        .xnair-region-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 20px;
            margin: 20px 0;
        }
        .xnair-region-card {
            background: #fff;
            border: 1px solid var(--border-color);
            border-radius: 10px;
            padding: 20px;
            box-shadow: var(--xnair-card-shadow);
            transition: box-shadow 0.3s ease;
        }
        .xnair-region-card:hover {
            box-shadow: 0 6px 24px rgba(0, 0, 0, 0.1);
        }
        .xnair-region-card h4 {
            font-size: 16px;
            font-weight: 700;
            color: var(--dark-charcoal);
            margin-bottom: 8px;
        }
        .xnair-region-card p {
            font-size: 14px;
            color: #475569;
            margin-bottom: 0;
            line-height: 1.6;
        }
        .xnair-region-icon {
            font-size: 32px;
            margin-bottom: 8px;
            display: block;
        }

        /* -- 工程细节列表 -- */
        .xnair-eng-list {
            list-style: none;
            padding-left: 0;
        }
        .xnair-eng-list li {
            position: relative;
            padding-left: 28px;
            margin-bottom: 12px;
            line-height: 1.6;
            color: #475569;
        }
        .xnair-eng-list li::before {
            content: '▸';
            position: absolute;
            left: 0;
            top: 0;
            color: var(--accent-blue);
            font-weight: 700;
            font-size: 16px;
        }

        /* -- FAQ -- */
        .xnair-faq-item {
            border: 1px solid var(--border-color);
            border-radius: 10px;
            margin-bottom: 14px;
            overflow: hidden;
            box-shadow: var(--xnair-card-shadow);
        }
        .xnair-faq-question {
            background: #fff;
            padding: 16px 20px;
            font-weight: 700;
            font-size: 15px;
            color: var(--dark-charcoal);
            cursor: pointer;
            position: relative;
            user-select: none;
            display: flex;
            align-items: center;
            gap: 10px;
        }
        .xnair-faq-question .xnair-faq-icon {
            color: var(--accent-blue);
            font-size: 18px;
            flex-shrink: 0;
        }
        .xnair-faq-answer {
            padding: 0 20px 18px 20px;
            font-size: 14px;
            color: #475569;
            line-height: 1.7;
            display: block;
        }
        .xnair-faq-answer p {
            margin-bottom: 8px;
        }

        /* -- 品质认证 -- */
        .xnair-quality-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 20px;
            margin: 16px 0;
        }
        .xnair-quality-item {
            background: #fff;
            border: 1px solid var(--border-color);
            border-radius: 8px;
            padding: 18px;
            display: flex;
            align-items: flex-start;
            gap: 12px;
            box-shadow: var(--xnair-card-shadow);
        }
        .xnair-quality-icon {
            font-size: 28px;
            flex-shrink: 0;
        }
        .xnair-quality-item h4 {
            font-size: 15px;
            font-weight: 700;
            color: var(--dark-charcoal);
            margin-bottom: 4px;
        }
        .xnair-quality-item p {
            font-size: 13px;
            color: #64748b;
            margin-bottom: 0;
        }

        /* -- 分页导航 -- */
        .xnair-pagination {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 28px 0;
            border-top: 2px solid var(--border-color);
            margin-top: 36px;
            gap: 20px;
            flex-wrap: wrap;
        }
        .xnair-pagination a {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            font-weight: 600;
            color: var(--accent-blue);
            font-size: 15px;
            padding: 10px 18px;
            border-radius: 8px;
            border: 1px solid var(--border-color);
            transition: all 0.25s ease;
            background: #fff;
        }
        .xnair-pagination a:hover {
            background: var(--xnair-highlight);
            border-color: #3399ff;
            color: #3399ff;
        }
        .xnair-pagination .xnair-prev::before {
            content: '←';
            font-size: 18px;
        }
        .xnair-pagination .xnair-next::after {
            content: '→';
            font-size: 18px;
        }

        /* -- 相关产品推荐 -- */
        .xnair-related-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 20px;
            margin: 16px 0;
        }
        .xnair-related-card {
            background: #fff;
            border: 1px solid var(--border-color);
            border-radius: 10px;
            padding: 16px;
            box-shadow: var(--xnair-card-shadow);
            transition: box-shadow 0.3s ease;
            text-align: center;
        }
        .xnair-related-card:hover {
            box-shadow: 0 6px 20px rgba(0, 0, 0, 0.1);
        }
        .xnair-related-card img {
            width: 100%;
            height: auto;
            aspect-ratio: 4/3;
            object-fit: cover;
            border-radius: 6px;
            margin-bottom: 10px;
            background: #f1f5f9;
        }
        .xnair-related-card h4 {
            font-size: 14px;
            font-weight: 700;
            color: var(--dark-charcoal);
            margin-bottom: 4px;
        }
        .xnair-related-card a {
            color: var(--accent-blue);
            font-weight: 600;
            font-size: 13px;
        }
        .xnair-related-card a:hover {
            color: #3399ff;
            text-decoration: underline;
        }

        /* ========== 响应式：产品页面专属 ========== */
        @media(max-width: 1024px) {
            .xnair-hero-grid {
                grid-template-columns: 1fr;
                gap: 28px;
            }
            .xnair-hero-content h1 {
                font-size: 1.6rem;
            }
            .xnair-main-layout {
                grid-template-columns: 1fr;
                gap: 20px;
            }
            .xnair-toc-wrap {
                display: none;
            }
            .xnair-toc-mobile-toggle {
                display: block;
            }
            .xnair-region-grid {
                grid-template-columns: 1fr 1fr;
            }
            .xnair-img-row {
                grid-template-columns: 1fr;
            }
            .xnair-quality-grid {
                grid-template-columns: 1fr;
            }
            .xnair-related-grid {
                grid-template-columns: 1fr 1fr;
            }
        }
        @media(max-width: 640px) {
            .xnair-hero-content h1 {
                font-size: 1.35rem;
            }
            .xnair-hero-badges {
                gap: 8px;
            }
            .xnair-hero-badge {
                font-size: 12px;
                padding: 6px 10px;
            }
            .xnair-region-grid {
                grid-template-columns: 1fr;
            }
            .xnair-related-grid {
                grid-template-columns: 1fr;
            }
            .xnair-pagination {
                flex-direction: column;
                align-items: stretch;
                text-align: center;
            }
            .xnair-btn-primary,
            .xnair-btn-outline {
                width: 100%;
                text-align: center;
                padding: 12px 20px;
                font-size: 14px;
            }
            .xnair-specs-table {
                font-size: 12px;
                min-width: 480px;
            }
            .xnair-specs-table thead th,
            .xnair-specs-table tbody td {
                padding: 8px 10px;
            }
        }