:root {
            --primary: #0A2540;
            --primary-light: #0E4D8C;
            --accent: #00C2A8;
            --accent-dark: #009B86;
            --cta: #FF7A1A;
            --cta-hover: #E56500;
            --bg: #F5F7FB;
            --text: #1A2B3C;
            --muted: #5A6B7C;
            --white: #ffffff;
            --footer-bg: #081426;
            --footer-text: rgba(255,255,255,0.75);
            --hero-gradient: linear-gradient(135deg, #0A2540 0%, #0E4D8C 55%, #00C2A8 130%);
            --card-shadow: 0 5px 18px rgba(10,37,64,0.08);
            --radius: 16px;
        }
        * { margin: 0; padding: 0; box-sizing: border-box; }
        body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif; line-height: 1.6; color: var(--text); background: var(--bg); }
        .container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }

        header { background: rgba(255,255,255,0.96); backdrop-filter: blur(12px); position: fixed; top: 0; left: 0; right: 0; z-index: 1000; box-shadow: 0 2px 12px rgba(10,37,64,0.08); transition: all 0.3s; }
        header.scrolled { background: rgba(255,255,255,0.99); }
        nav { display: flex; justify-content: space-between; align-items: center; padding: 15px 0; }
        .logo { display: flex; align-items: center; gap: 10px; text-decoration: none; color: var(--primary); font-size: 24px; font-weight: bold; }
        .logo img { height: 40px; }
        .logo span { color: var(--accent-dark); }
        .nav-links { display: flex; gap: 22px; list-style: none; }
        .nav-links a { text-decoration: none; color: var(--text); font-weight: 500; transition: color 0.3s; position: relative; font-size: 15px; }
        .nav-links a:hover, .nav-links a.active { color: var(--accent-dark); }
        .nav-links a.active::after { content: ''; position: absolute; bottom: -5px; left: 0; right: 0; height: 2px; background: var(--accent); }
        .nav-right { display: flex; align-items: center; gap: 16px; }
        .lang-switch select { padding: 8px 28px 8px 12px; border: 1px solid #ddd; border-radius: 6px; background: white; cursor: pointer; color: var(--text); }
        .login-btn { padding: 8px 20px; background: var(--cta); color: white; border: none; border-radius: 6px; cursor: pointer; text-decoration: none; font-weight: 500; transition: background 0.3s; }
        .login-btn:hover { background: var(--cta-hover); }
        .mobile-menu-btn { display: none; background: none; border: none; font-size: 24px; cursor: pointer; color: var(--primary); }

        /* Hero 区域 */
        .hero { padding: 140px 0 80px; background: var(--hero-gradient); color: white; position: relative; overflow: hidden; }
        .hero::before { content: ''; position: absolute; top: 0; left: 0; right: 0; bottom: 0; background: radial-gradient(circle at 20% 20%, rgba(255,255,255,0.12) 0%, transparent 40%), radial-gradient(circle at 80% 80%, rgba(0,194,168,0.18) 0%, transparent 40%); }
        .hero-content { position: relative; z-index: 1; max-width: 800px; margin: 0 auto; text-align: center; }
        .hero-text h1 { font-size: 48px; margin-bottom: 20px; line-height: 1.2; color: #fff; }
        .hero-text .sub { font-size: 19px; margin-bottom: 30px; opacity: 0.92; }
        .hero-stats { display: flex; justify-content: center; gap: 40px; flex-wrap: wrap; margin-bottom: 30px; }
        .hero-stat { text-align: center; }
        .hero-stat .number { font-size: 36px; font-weight: bold; display: block; color: #fff; }
        .hero-stat .label { font-size: 14px; opacity: 0.85; }
        .btn-primary { padding: 14px 32px; background: var(--cta); color: white; border: none; border-radius: 8px; font-size: 16px; font-weight: 600; cursor: pointer; text-decoration: none; display: inline-block; transition: all 0.3s; animation: pulse 2s infinite; }
        .btn-primary:hover { background: var(--cta-hover); transform: translateY(-2px); box-shadow: 0 10px 20px rgba(255,122,26,0.35); }

        @keyframes pulse { 0%, 100% { box-shadow: 0 0 0 0 rgba(255,122,26,0.4); } 50% { box-shadow: 0 0 0 10px rgba(255,122,26,0); } }

        /* 通用 section 样式 */
        .section { padding: 80px 0; }
        .section-title { text-align: center; font-size: 34px; margin-bottom: 12px; color: var(--primary); }
        .section-subtitle { text-align: center; font-size: 17px; color: var(--muted); margin-bottom: 48px; }

        /* 创意版块1：起源叙事 */
        .origin-story { background: white; }
        .story-layout { display: grid; grid-template-columns: 1fr 1fr; gap: 50px; align-items: center; }
        .story-text h3 { font-size: 24px; margin-bottom: 15px; color: var(--primary); }
        .story-text p { color: var(--muted); font-size: 16px; margin-bottom: 15px; line-height: 1.8; }
        .story-quote { background: #F0F4FA; border-left: 4px solid var(--accent); padding: 20px; border-radius: 0 var(--radius) var(--radius) 0; font-style: italic; color: var(--text); }
        .story-visual { text-align: center; }
        .story-visual .big-icon { font-size: 120px; margin-bottom: 20px; }

        /* 创意版块2：初心使命卡片 */
        .mission-values { background: linear-gradient(135deg, #EDF3FA 0%, #D9E8F5 100%); }
        .value-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 28px; }
        .value-card { background: white; padding: 30px; border-radius: var(--radius); text-align: center; box-shadow: var(--card-shadow); transition: transform 0.3s; }
        .value-card:hover { transform: translateY(-6px); }
        .value-icon { font-size: 42px; margin-bottom: 14px; }
        .value-card h3 { font-size: 20px; margin-bottom: 10px; color: var(--primary); }
        .value-card p { color: var(--muted); font-size: 15px; }

        /* 创意版块3：里程碑时间线 */
        .milestones { background: white; }
        .timeline { position: relative; max-width: 800px; margin: 0 auto; }
        .timeline::before { content: ''; position: absolute; left: 50%; top: 0; bottom: 0; width: 2px; background: #E0E7EF; transform: translateX(-50%); }
        .timeline-item { display: flex; justify-content: flex-end; padding-left: 50%; position: relative; margin-bottom: 40px; }
        .timeline-item:nth-child(even) { justify-content: flex-start; padding-left: 0; padding-right: 50%; }
        .timeline-content { width: calc(100% - 30px); background: #F8FAFD; padding: 20px; border-radius: var(--radius); box-shadow: var(--card-shadow); }
        .timeline-year { font-size: 20px; color: var(--accent-dark); font-weight: 700; margin-bottom: 6px; }
        .timeline-title { font-size: 18px; font-weight: 600; color: var(--primary); margin-bottom: 6px; }
        .timeline-desc { color: var(--muted); font-size: 15px; }
        .timeline-item::after { content: ''; position: absolute; top: 20px; left: 50%; width: 12px; height: 12px; border-radius: 50%; background: var(--accent); transform: translateX(-50%); }

        /* 创意版块4：用户价值主张 */
        .user-promise { background: #F0F4FA; }
        .promise-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 24px; }
        .promise-card { background: #F8FAFD; border-radius: var(--radius); padding: 28px 20px; text-align: center; border: 1px solid #E7EDF5; transition: all 0.3s; }
        .promise-card:hover { border-color: var(--accent); box-shadow: var(--card-shadow); transform: translateY(-5px); }
        .promise-icon { font-size: 36px; margin-bottom: 12px; }
        .promise-card h3 { font-size: 18px; margin-bottom: 8px; color: var(--primary); }
        .promise-card p { color: var(--muted); font-size: 14px; }

        /* 创意版块5：技术坚守信念 */
        .tech-faith { background: white; }
        .faith-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 28px; }
        .faith-card { background: #F8FAFD; border-radius: var(--radius); padding: 30px; box-shadow: var(--card-shadow); }
        .faith-card h3 { font-size: 20px; margin-bottom: 12px; color: var(--accent-dark); }
        .faith-card ul { list-style: none; }
        .faith-card li { padding: 10px 0; border-bottom: 1px solid #eee; display: flex; align-items: center; gap: 10px; color: var(--text); }
        .faith-card li:before { content: '✓'; color: var(--accent); font-weight: bold; }

        /* 数据指标区 */
        .metrics-banner { background: var(--hero-gradient); color: white; padding: 60px 0; text-align: center; }
        .metrics-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(160px, 1fr)); gap: 30px; max-width: 900px; margin: 0 auto; }
        .metric-item .metric-value { font-size: 40px; font-weight: bold; }
        .metric-item .metric-label { font-size: 14px; opacity: 0.9; }

        /* FAQ */
        .faq { padding: 80px 0; background: #F0F4FA; }
        .faq-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(420px, 1fr)); gap: 20px; margin-top: 20px; }
        .faq-item { background: white; border-radius: 12px; overflow: hidden; box-shadow: var(--card-shadow); }
        .faq-question { padding: 20px; cursor: pointer; display: flex; justify-content: space-between; align-items: center; font-weight: 600; font-size: 16px; color: var(--primary); }
        .faq-question:hover { background: #F1F5FA; }
        .faq-question .arrow { transition: transform 0.3s; color: var(--accent-dark); }
        .faq-item.active .faq-question .arrow { transform: rotate(180deg); }
        .faq-answer { padding: 0 20px; max-height: 0; overflow: hidden; transition: all 0.35s; }
        .faq-item.active .faq-answer { padding: 0 20px 20px; max-height: 800px; }
        .faq-answer p { color: var(--muted); line-height: 1.7; }

        /* 下载区域 */
        .download { padding: 80px 0; background: var(--hero-gradient); color: white; text-align: center; }
        .download h2 { font-size: 34px; margin-bottom: 14px; color: #fff; }
        .download p { font-size: 18px; margin-bottom: 36px; opacity: 0.9; }
        .download-platforms { display: flex; justify-content: center; gap: 18px; flex-wrap: wrap; }
        .download-btn { padding: 15px 28px; background: white; color: var(--primary); border-radius: 10px; text-decoration: none; font-weight: 600; display: flex; align-items: center; gap: 10px; transition: all 0.3s; }
        .download-btn:hover { transform: translateY(-3px); box-shadow: 0 10px 20px rgba(0,0,0,0.2); }
        .download-btn .icon { font-size: 24px; }

        /* Footer */
        footer { background: var(--footer-bg); color: white; padding: 60px 0 20px; }
        .footer-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 40px; margin-bottom: 36px; }
        .footer-col h3 { font-size: 18px; margin-bottom: 18px; color: var(--accent); }
        .footer-col ul { list-style: none; }
        .footer-col li { margin-bottom: 10px; }
        .footer-col a { color: var(--footer-text); text-decoration: none; transition: color 0.3s; }
        .footer-col a:hover { color: white; }
        .footer-bottom { border-top: 1px solid rgba(255,255,255,0.1); padding-top: 20px; text-align: center; color: rgba(255,255,255,0.5); font-size: 14px; }
        .footer-bottom a { color: var(--footer-text); }
        #my-friend-links { margin-top: 20px; padding: 15px; background: rgba(255,255,255,0.05); border-radius: 8px; color: var(--footer-text); }
        #my-friend-links a { color: var(--footer-text); margin: 0 10px; text-decoration: none; }
        #my-friend-links a:hover { color: white; }

        @media (max-width: 768px) {
            .nav-links { display: none; }
            .mobile-menu-btn { display: block; }
            .hero-text h1 { font-size: 32px; }
            .hero-stats { gap: 20px; }
            .story-layout { grid-template-columns: 1fr; }
            .value-grid, .promise-grid, .faith-grid, .faq-grid { grid-template-columns: 1fr; }
            .timeline-item, .timeline-item:nth-child(even) { padding-left: 30px; padding-right: 0; justify-content: flex-start; }
            .timeline::before { left: 15px; }
            .timeline-item::after { left: 15px; }
            .download-platforms { flex-direction: column; align-items: center; }
        }