/* =========================================
           1. 全局变量与基础设置
           ========================================= */
        :root {
            /* 品牌色 */
            --primary-blue: #00457C;  /* 深海蓝 - 稳重 */
            --tech-blue: #009FE3;     /* 科技蓝 - 活力 */
            --brand-orange: #FF6600;  /* 赫兹橙 - 强调/按钮 */
            
            /* 界面色 */
            --text-dark: #222222;
            --text-gray: #555555;
            --bg-light: #F9FAFB;
            --white: #FFFFFF;
            --border-color: #E5E7EB;

            /* 布局 */
            --container-width: 1100px;
        }

        * { margin: 0; padding: 0; box-sizing: border-box; }
        
        body { 
            font-family: 'Open Sans', sans-serif; 
            color: var(--text-dark); 
            line-height: 1.6; 
            background-color: var(--white);
            -webkit-font-smoothing: antialiased;
        }

        a { text-decoration: none; transition: 0.3s; }
        h1, h2, h3, h4 { font-family: 'Roboto', sans-serif; color: var(--primary-blue); margin-bottom: 1rem; }
        img { max-width: 100%; display: block; }

        /* =========================================
           2. 通用组件
           ========================================= */
        .container { max-width: var(--container-width); margin: 0 auto; padding: 0 20px; }
        .section { padding: 80px 0; }
        .bg-light { background-color: var(--bg-light); }
        .text-center { text-align: center; }

        /* 按钮样式 */
        .btn {
            display: inline-block;
            padding: 14px 36px;
            font-weight: 700;
            font-family: 'Roboto', sans-serif;
            text-transform: uppercase;
            font-size: 14px;
            border-radius: 4px;
            letter-spacing: 0.5px;
            cursor: pointer;
            transition: all 0.3s ease;
            box-shadow: 0 4px 6px rgba(0,0,0,0.1);
        }
        
        /* 主要按钮 (橙色) */
        .btn-primary {
            background-color: var(--brand-orange);
            color: var(--white);
            border: 2px solid var(--brand-orange);
        }
        .btn-primary:hover {
            background-color: #E65C00;
            border-color: #E65C00;
            transform: translateY(-2px);
            box-shadow: 0 8px 15px rgba(255, 102, 0, 0.2);
        }

        /* 描边按钮 (透明/白色) */
        .btn-outline {
            background: transparent;
            color: var(--white);
            border: 2px solid rgba(255,255,255,0.4);
        }
        .btn-outline:hover {
            border-color: var(--white);
            background: rgba(255,255,255,0.1);
        }

        /* 标题修饰线条 */
        h2.section-title { font-size: 32px; font-weight: 700; position: relative; margin-bottom: 60px; }
        h2.section-title::after {
            content: ''; display: block; width: 60px; height: 4px; 
            background: var(--brand-orange); margin: 15px auto 0;
            border-radius: 2px;
        }

        /* =========================================
           3. Hero 区域 (首屏)
           ========================================= */
        .hero {
            background: linear-gradient(160deg, #002845 0%, #00457C 100%);
            color: var(--white);
            padding: 60px 0 100px;
            position: relative;
            overflow: hidden;
        }

        /* 品牌 Logo 展示 */
        .brand-header { margin-bottom: 60px; }
        .brand-logo { font-size: 28px; font-weight: 900; color: var(--white); letter-spacing: 1px; font-family: 'Roboto', sans-serif; }
        .brand-logo span { color: var(--brand-orange); }

        .hero-content { display: grid; grid-template-columns: 1fr 1fr; gap: 80px; align-items: center; }

        .hero-text h1 { 
            color: var(--white); font-size: 48px; line-height: 1.1; 
            font-weight: 700; margin-bottom: 24px; 
        }
        .hero-text p { 
            font-size: 18px; opacity: 0.9; margin-bottom: 40px; 
            font-weight: 300; max-width: 500px; 
        }

        /* 产品展示框 (模拟图) */
        .product-mockup {
            background: rgba(255,255,255,0.05);
            border: 1px solid rgba(255,255,255,0.1);
            backdrop-filter: blur(10px);
            border-radius: 12px;
            padding: 30px;
            text-align: center;
            box-shadow: 0 25px 50px rgba(0,0,0,0.25);
            transition: transform 0.5s;
        }
        .product-mockup:hover { transform: translateY(-5px); }

        /* 图片占位符样式 (如果没有图片) */
        .mockup-img-placeholder {
            height: 280px; 
            background: #f0f0f0; 
            border-radius: 6px; 
            display: flex; 
            align-items: center; 
            justify-content: center;
            color: #888; 
            font-weight: bold; 
            margin-bottom: 20px;
            border: 2px dashed #ccc;
            position: relative;
        }
        /* 如果有真实图片，占位符样式会被覆盖 */
        .mockup-img-placeholder img {
            width: 100%;
            height: 100%;
            object-fit: contain; /* 保持图片比例 */
        }

        /* =========================================
           4. 核心特性 (Features)
           ========================================= */
        .features-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px; }
        
        .feature-card {
            background: var(--white); 
            padding: 40px 30px; 
            border-radius: 8px;
            border: 1px solid var(--border-color);
            transition: 0.3s;
        }
        .feature-card:hover { 
            border-color: var(--primary-blue); 
            transform: translateY(-5px);
            box-shadow: 0 10px 30px rgba(0,69,124,0.08);
        }
        
        .f-icon { 
            font-size: 24px; color: var(--primary-blue); margin-bottom: 20px; 
            background: #F0F7FC; width: 60px; height: 60px; 
            display: flex; align-items: center; justify-content: center; border-radius: 50%;
        }
        .feature-card h3 { font-size: 20px; font-weight: 700; margin-bottom: 12px; }
        .feature-card p { font-size: 14px; color: var(--text-gray); }

        /* =========================================
           5. 规格参数表 (Table)
           ========================================= */
        .table-container { 
            background: var(--white); border-radius: 8px; 
            overflow: hidden; box-shadow: 0 4px 20px rgba(0,0,0,0.05); 
        }
        table { width: 100%; border-collapse: collapse; }
        th { background: var(--primary-blue); color: var(--white); padding: 18px 24px; text-align: left; font-weight: 600; }
        td { padding: 16px 24px; border-bottom: 1px solid #eee; color: #444; font-size: 15px; }
        tr:nth-child(even) { background: #F8F9FA; }
        tr:last-child td { border-bottom: none; }

        /* =========================================
           6. 应用场景 (Dark Theme)
           ========================================= */
        .dark-section { background: #1A1A1A; color: var(--white); }
        .dark-section h2 { color: var(--white); }
        .dark-section p.subtitle { color: #888; }
        
        .app-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
        
        .app-card {
            background: #262626; padding: 30px; 
            border-radius: 6px; 
            border-left: 4px solid var(--brand-orange);
            transition: background 0.3s;
        }
        .app-card:hover { background: #333; }
        .app-card h4 { color: var(--white); font-size: 18px; margin-bottom: 10px; }
        .app-card p { color: #aaa; font-size: 14px; margin: 0; }

        /* =========================================
           7. 页脚 (Footer)
           ========================================= */
        footer { background: #111; padding: 60px 0 30px; color: #666; font-size: 14px; text-align: center; }
        footer h2 { color: var(--white); font-size: 28px; margin-bottom: 15px; }
        footer p { max-width: 600px; margin: 0 auto 30px; color: #888; }
        
        .footer-bottom { 
            border-top: 1px solid #222; margin-top: 50px; padding-top: 30px; 
            display: flex; justify-content: center; gap: 40px;
        }
        .contact-pill {
            background: #222; padding: 5px 15px; border-radius: 20px; font-size: 13px; color: #999;
        }

        /* =========================================
           8. 移动端适配 (Responsive)
           ========================================= */
        @media (max-width: 768px) {
            .hero-content { grid-template-columns: 1fr; gap: 40px; text-align: center; }
            .hero-text h1 { font-size: 36px; }
            .hero-text p { margin: 0 auto 30px; }
            .hero-content .cta-group { justify-content: center; display: flex; }
            
            .features-grid, .app-grid { grid-template-columns: 1fr; }
            .table-container { overflow-x: auto; }
            
            .section { padding: 60px 0; }
            .footer-bottom { flex-direction: column; gap: 20px; }
        }