/* ===== 全局样式 ===== */
        :root {
            --primary: #1e2b3a;
            --secondary: #e67e22;
            --light-grey: #f8f9fa;
            --basic: #3498db;
            --pro: #2ecc71;
            --premium: #9b59b6;
            --text-muted: #6b7a8a;
            --border-light: #e9ecef;
        }

        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Inter', 'Roboto', Arial, sans-serif;
        }

        body {
            background: #ffffff;
            color: var(--primary);
            line-height: 1.6;
        }

        .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 24px;
        }

        /* ===== 版块标题 ===== */
        .section-header {
            text-align: center;
            margin: 4rem 0 3rem;
            position: relative;
        }
        .section-header h2 {
            font-size: 2.2rem;
            font-weight: 600;
            display: inline-block;
            padding: 0 2rem;
            background: #fff;
            position: relative;
            letter-spacing: -0.02em;
        }
        .section-header::after {
            content: "";
            position: absolute;
            left: 50%;
            bottom: -0.8rem;
            transform: translateX(-50%);
            width: 60px;
            height: 3px;
            background: var(--secondary);
            border-radius: 2px;
        }

        /* ===== 产品主图 ===== */
        .product-hero {
            text-align: center;
            padding: 2rem 0 1.5rem;
        }
        .product-hero h1 {
            font-size: 2.8rem;
            font-weight: 700;
            letter-spacing: -0.02em;
            margin-bottom: 0.4rem;
        }
        .product-hero .subtitle {
            font-size: 1.2rem;
            color: var(--text-muted);
            font-weight: 400;
        }
        .product-hero .hero-tagline {
            font-size: 1.05rem;
            color: #3d4e5e;
            max-width: 760px;
            margin: 0.6rem auto 1.8rem;
        }

        /* 关键指标卡片（横向） */
        .hero-metrics {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 1.2rem;
            max-width: 900px;
            margin: 1.5rem auto 0;
        }
        .hero-metric {
            background: var(--light-grey);
            padding: 1.2rem 0.8rem;
            border-radius: 12px;
            text-align: center;
            border: 1px solid var(--border-light);
            transition: transform 0.2s ease;
        }
        .hero-metric:hover {
            transform: translateY(-3px);
        }
        .hero-metric strong {
            display: block;
            font-size: 1.6rem;
            font-weight: 700;
            color: var(--secondary);
        }
        .hero-metric span {
            font-size: 0.9rem;
            color: var(--text-muted);
        }

        /* ===== 特色卡片 ===== */
        .feature-card {
            background: #fff;
            padding: 2.2rem 2.5rem;
            margin: 1.2rem 0;
            border-radius: 14px;
            box-shadow: 0 4px 20px rgba(0, 0, 0, 0.06);
            border: 1px solid var(--border-light);
            transition: box-shadow 0.25s ease;
        }
        .feature-card:hover {
            box-shadow: 0 8px 32px rgba(0, 0, 0, 0.09);
        }

        /* ===== Product Advantages 网格 — 固定一行两个，共两行 ===== */
        .feature-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;  /* 固定两列 */
            gap: 2rem;
            margin: 2.5rem 0;
        }

        /* ===== 产品卡片（版本/特性） ===== */
        .product-row {
            display: flex;
            justify-content: space-between;
            gap: 25px;
            margin: 30px 0;
        }
        .product-card {
            flex: 1;
            background: #fff;
            border-radius: 14px;
            overflow: hidden;
            box-shadow: 0 4px 18px rgba(0, 0, 0, 0.07);
            transition: transform 0.25s ease, box-shadow 0.25s ease;
            display: flex;
            flex-direction: column;
            border: 1px solid var(--border-light);
        }
        .product-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 10px 36px rgba(0, 0, 0, 0.10);
        }
        .card-header {
            padding: 1.4rem 1.2rem;
            text-align: center;
            color: #fff;
        }
        .card-header .product-name {
            font-size: 1.15rem;
            font-weight: 600;
        }
        .card-header .product-version {
            font-size: 0.95rem;
            opacity: 0.9;
        }

        .basic-bg {
            background: linear-gradient(135deg, #2c7be0, #1a5bbf);
        }
        .pro-bg {
            background: linear-gradient(135deg, #27ae60, #1e8e4a);
        }
        .premium-bg {
            background: linear-gradient(135deg, #8e44ad, #6c3483);
        }
        .accent-bg {
            background: linear-gradient(135deg, #e67e22, #d35400);
        }

        .product-card .product-image {
            padding: 1.2rem 0.5rem 0.5rem;
            text-align: center;
        }
        .product-card .product-image img {
            max-width: 85%;
            height: auto;
            border-radius: 6px;
        }
        .product-card .product-body {
            padding: 1rem 1.4rem 1.6rem;
            text-align: center;
            flex: 1;
            font-size: 0.95rem;
            color: #2d3f4f;
        }
        .product-card .product-body .feature-tag {
            display: inline-block;
            background: var(--light-grey);
            padding: 0.2rem 0.9rem;
            border-radius: 20px;
            font-size: 0.8rem;
            font-weight: 500;
            color: var(--text-muted);
            margin: 0.2rem 0.3rem;
        }

        /* ===== 规格表格 ===== */
        .specs-table {
            width: 100%;
            border-collapse: collapse;
            margin: 1.8rem 0;
            font-size: 0.95rem;
            border-radius: 12px;
            overflow: hidden;
            box-shadow: 0 2px 12px rgba(0, 0, 0, 0.05);
        }
        .specs-table td,
        .specs-table th {
            padding: 0.9rem 1.2rem;
            border-bottom: 1px solid var(--border-light);
            vertical-align: top;
        }
        .specs-table tr:last-child td,
        .specs-table tr:last-child th {
            border-bottom: none;
        }
        .specs-table th {
            font-weight: 600;
            color: var(--secondary);
            width: 30%;
            background: #fafbfc;
            text-align: left;
        }
        .specs-table td {
            background: #fff;
        }
        .specs-table .note-row td {
            background: #fafbfc;
            font-size: 0.88rem;
            color: var(--text-muted);
            padding: 0.8rem 1.2rem;
            border-top: 1px solid var(--border-light);
        }

        /* ===== 应用场景 ===== */
        .use-cases {
            display: grid;
            grid-template-columns: repeat(2, 1fr);
            gap: 2.5rem;
            margin: 2.5rem auto;
            max-width: 820px;
        }
        .use-case {
            text-align: center;
            background: #fff;
            border-radius: 14px;
            padding: 1.2rem 1rem 1.4rem;
            border: 1px solid var(--border-light);
            transition: transform 0.2s ease, box-shadow 0.2s ease;
        }
        .use-case:hover {
            transform: translateY(-4px);
            box-shadow: 0 8px 28px rgba(0, 0, 0, 0.08);
        }
        .use-case img {
            width: 100%;
            height: 200px;
            object-fit: cover;
            border-radius: 10px;
            margin-bottom: 0.8rem;
            background: var(--light-grey);
        }
        .use-case .use-label {
            font-weight: 600;
            font-size: 1.1rem;
            color: var(--primary);
        }
        .use-case .use-desc {
            font-size: 0.92rem;
            color: var(--text-muted);
            margin-top: 0.3rem;
        }

        /* ===== 环保板块 ===== */
        .eco-section {
            background: var(--light-grey);
            padding: 3.5rem 2rem;
            border-radius: 16px;
            margin: 3.5rem 0;
            text-align: center;
            border: 1px solid var(--border-light);
        }
        .eco-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 2rem;
            margin-top: 2rem;
        }
        .eco-card h3 {
            font-size: 2rem;
            font-weight: 700;
            color: var(--secondary);
        }
        .eco-card p {
            color: var(--text-muted);
            font-size: 0.95rem;
        }

        /* ===== 下载区 ===== */
        .downloads {
            border-left: 4px solid var(--secondary);
            padding-left: 1.8rem;
            margin: 2rem 0;
        }
        .downloads a {
            color: var(--primary);
            text-decoration: none;
            display: block;
            margin: 0.7rem 0;
            transition: color 0.2s ease;
            font-size: 0.95rem;
            border-bottom: 1px dashed transparent;
        }
        .downloads a:hover {
            color: var(--secondary);
            border-bottom-color: var(--secondary);
        }

        /* ===== 系统架构图 ===== */
        .arch-diagram {
            display: flex;
            flex-wrap: wrap;
            align-items: center;
            justify-content: center;
            gap: 1rem 0.5rem;
            margin: 2rem 0 1rem;
            padding: 1.8rem 1.2rem;
            background: var(--light-grey);
            border-radius: 16px;
            border: 1px solid var(--border-light);
        }
        .arch-node {
            background: #fff;
            padding: 1rem 1.6rem;
            border-radius: 10px;
            box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
            text-align: center;
            min-width: 120px;
            border: 1px solid var(--border-light);
            font-weight: 500;
        }
        .arch-node .node-label {
            font-size: 0.8rem;
            font-weight: 400;
            color: var(--text-muted);
            display: block;
            margin-top: 0.15rem;
        }
        .arch-arrow {
            font-size: 1.6rem;
            color: var(--secondary);
            font-weight: 300;
            padding: 0 0.2rem;
        }
        .arch-arrow-sm {
            font-size: 1.2rem;
            color: var(--secondary);
        }

        /* ===== 响应式 ===== */
        @media (max-width: 992px) {
            .hero-metrics {
                grid-template-columns: repeat(2, 1fr);
            }
        }
        @media (max-width: 768px) {
            .product-row {
                flex-direction: column;
                gap: 1.5rem;
            }
            .use-cases {
                grid-template-columns: 1fr;
                max-width: 500px;
            }
            .use-case img {
                height: 180px;
            }
            .eco-grid {
                grid-template-columns: 1fr;
            }
            .section-header h2 {
                font-size: 1.6rem;
                padding: 0 1rem;
            }
            .product-hero h1 {
                font-size: 2rem;
            }
            .hero-metrics {
                grid-template-columns: 1fr 1fr;
                gap: 0.8rem;
            }
            .specs-table th,
            .specs-table td {
                padding: 0.6rem 0.8rem;
                font-size: 0.88rem;
            }
            .arch-diagram {
                flex-direction: column;
                gap: 0.6rem;
            }
            .arch-arrow {
                transform: rotate(90deg);
            }

            /* ===== Product Advantages 移动端变为一列 ===== */
            .feature-grid {
                grid-template-columns: 1fr;
            }
        }
        @media (max-width: 480px) {
            .hero-metrics {
                grid-template-columns: 1fr;
            }
            .product-hero h1 {
                font-size: 1.6rem;
            }
            .use-case img {
                height: 160px;
            }
        }