/* 全局样式复位与变量设置 */
        * { box-sizing: border-box; margin: 0; padding: 0; }
        body { font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif; color: #2c3e50; line-height: 1.6; background-color: #f8fafc; }
        .container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }
        
        /* 1. 优化后的现代化导航栏 */
        .header { 
            background: rgba(255, 255, 255, 0.9); 
            backdrop-filter: blur(10px); 
            box-shadow: 0 2px 15px rgba(0,0,0,0.06); 
            position: sticky; 
            top: 0; 
            z-index: 1000; 
            transition: all 0.3s ease;
        }
        .nav-content { display: flex; justify-content: space-between; align-items: center; height: 75px; }
        .logo-box { display: flex; align-items: center; text-decoration: none; }
        .logo-box img { max-height: 42px; width: auto; transition: transform 0.3s; }
        .logo-box:hover img { transform: scale(1.03); }
        
        .nav-links { display: flex; align-items: center; gap: 30px; }
        .nav-links a { color: #4a5568; text-decoration: none; font-weight: 500; font-size: 1rem; transition: all 0.2s ease; position: relative; }
        .nav-links a:hover { color: #0088cc; }
        .nav-links a::after { content: ''; position: absolute; width: 0; height: 2px; bottom: -4px; left: 0; background-color: #0088cc; transition: width 0.3s ease; }
        .nav-links a:hover::after { width: 100%; }
        
        .nav-cta { background: #0088cc; color: #fff !important; padding: 8px 20px; border-radius: 20px; font-weight: 600 !important; box-shadow: 0 4px 12px rgba(0, 136, 204, 0.25); }
        .nav-cta:hover { background: #0077b5; transform: translateY(-1px); }
        .nav-cta::after { display: none !important; }

        /* 首屏/下载区 */
        .hero-section { padding: 60px 0; text-align: center; background: linear-gradient(180deg, #ffffff 0%, #edf2f7 100%); }
        .hero-section h1 { font-size: 2.6rem; margin-bottom: 15px; color: #1a202c; font-weight: 700; }
        .hero-section .hero-desc { max-width: 720px; margin: 0 auto 40px; color: #718096; font-size: 1.1rem; }
        
        .download-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 25px; margin-top: 30px; }
        .download-card { background: #fff; border-radius: 16px; padding: 25px; box-shadow: 0 10px 25px rgba(0,0,0,0.03); border: 1px solid #edf2f7; display: flex; flex-direction: column; align-items: center; transition: all 0.3s ease; }
        .download-card:hover { transform: translateY(-6px); box-shadow: 0 15px 35px rgba(0,0,0,0.08); }
        .demo-screen { max-width: 100%; height: 180px; object-fit: contain; margin-bottom: 20px; border-radius: 8px; }
        .btn-download { width: 100%; padding: 12px 20px; border-radius: 10px; color: #fff; text-decoration: none; display: flex; align-items: center; justify-content: center; gap: 10px; font-weight: 600; transition: opacity 0.2s; }
        .btn-download:hover { opacity: 0.9; }
        .btn-pc { background-color: #0088cc; }
        .btn-android { background-color: #4caf50; }
        .btn-ios { background-color: #2d3748; }
        .btn-download img { width: 20px; height: 20px; }

        /* 特性网格 */
        .features-section { padding: 70px 0; background: #fff; }
        .section-title { text-align: center; margin-bottom: 45px; font-size: 2rem; color: #1a202c; }
        .grid-container { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 25px; }
        .grid-item { text-align: center; padding: 25px 20px; border-radius: 12px; background: #f8fafc; border: 1px solid #f1f5f9; transition: transform 0.2s; }
        .grid-item:hover { transform: translateY(-3px); }
        .grid-item img { width: 56px; height: 56px; margin-bottom: 15px; }
        .grid-item h4 { margin-bottom: 8px; font-size: 1.15rem; color: #2d3748; }
        .grid-item p { color: #64748b; font-size: 0.92rem; }

        /* 2. 必应 (Bing) SEO 优化区域 1：优势对比与核心价值卡片 */
        .bing-advantages-section { padding: 70px 0; background: #f1f5f9; }
        .advantage-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); gap: 30px; }
        .advantage-card { background: #ffffff; padding: 30px; border-radius: 12px; border-top: 4px solid #0088cc; box-shadow: 0 4px 6px rgba(0, 0, 0, 0.02); }
        .advantage-card h3 { font-size: 1.3rem; color: #1e293b; margin-bottom: 12px; display: flex; align-items: center; gap: 10px; }
        .advantage-card p { color: #475569; font-size: 0.95rem; line-height: 1.7; }
        .advantage-tag { background: #e0f2fe; color: #0369a1; font-size: 0.8rem; padding: 3px 8px; border-radius: 4px; font-weight: 600; }

        /* 3. 必应 (Bing) SEO 优化区域 2：步骤化指南 (搜索摘要/Rich Snippets友好) */
        .bing-guide-section { padding: 70px 0; background: #ffffff; }
        .steps-wrapper { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 20px; margin-top: 35px; }
        .step-item { background: #f8fafc; border: 1px dashed #cbd5e1; padding: 25px; border-radius: 12px; position: relative; }
        .step-number { font-size: 2rem; font-weight: 800; color: #0088cc; opacity: 0.3; position: absolute; top: 15px; right: 20px; }
        .step-item h4 { font-size: 1.1rem; color: #0f172a; margin-bottom: 10px; }
        .step-item p { font-size: 0.9rem; color: #64748b; }

        /* 页脚 */
        .footer { background: #0f172a; color: #94a3b8; text-align: center; padding: 35px 0; margin-top: 40px; }
        .footer p { font-size: 0.9rem; }