/* 极简重置 · 统一风格 */
        *{margin:0;padding:0;box-sizing:border-box;}
        body{font-family:system-ui,-apple-system,'Segoe UI',Roboto,'Helvetica Neue',sans-serif;background:#f5f7fc;color:#1e1f2a;line-height:1.5;-webkit-font-smoothing:antialiased;}
        .wrapper{max-width:1200px;margin:0 auto;padding:0 24px;}
        .nav-bar{display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;padding:18px 0;border-bottom:1px solid rgba(0,0,0,0.05);}
        .logo-area{font-weight:700;font-size:1.5rem;letter-spacing:-0.02em;background:linear-gradient(135deg,#0b1c3a 0%,#2a5c9e 100%);-webkit-background-clip:text;background-clip:text;color:transparent;}
        .logo-area span{font-weight:400;font-size:0.9rem;color:#5e6f8d;margin-left:6px;background:none;-webkit-background-clip:unset;background-clip:unset;color:#5e6f8d;}
        .nav-links{display:flex;gap:28px;font-weight:500;}
        .nav-links a{text-decoration:none;color:#2c3e50;font-size:1rem;transition:color 0.15s;}
        .nav-links a:hover{color:#1e5fd9;}
        .nav-links a.active{color:#1e5fd9;font-weight:600;border-bottom:2px solid #1e5fd9;padding-bottom:4px;}
        .nav-download-btn{background:#1e5fd9;color:white !important;padding:10px 22px;border-radius:60px;font-weight:600;font-size:0.95rem;box-shadow:0 6px 14px rgba(30,95,217,0.25);transition:all 0.2s;border:none;display:inline-block;text-decoration:none;}
        .nav-download-btn:hover{background:#154bb5;transform:translateY(-1px);box-shadow:0 10px 20px rgba(30,95,217,0.3);}

        .page-header{margin:40px 0 20px;}
        .page-header h1{font-size:2.5rem;font-weight:700;letter-spacing:-0.02em;color:#0a1a2b;max-width:900px;}
        .page-header .subhead{font-size:1.2rem;color:#406180;margin-top:12px;border-left:4px solid #1e5fd9;padding-left:20px;}

        /* 概念卡片区 */
        .concept-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:24px;margin:30px 0 40px;}
        .concept-card{background:#ffffff;border-radius:28px;padding:26px 22px;box-shadow:0 12px 24px -8px rgba(0,20,50,0.06);border:1px solid #e9eff8;}
        .concept-icon{font-size:2.4rem;margin-bottom:16px;}
        .concept-card h3{font-size:1.5rem;margin-bottom:12px;color:#0f2b4f;}
        .concept-card p{color:#3a5c7c;}

        /* 工作原理流程图 (创意差异化) */
        .workflow-section{background:linear-gradient(105deg,#ffffff 0%,#f3f9ff 100%);border-radius:36px;padding:32px 36px;margin:30px 0;border:1px solid #d0e2fc;}
        .workflow-title{font-size:1.9rem;font-weight:650;margin-bottom:28px;display:flex;align-items:center;gap:12px;}
        .workflow-steps{display:flex;align-items:center;justify-content:space-around;flex-wrap:wrap;gap:16px;}
        .wf-item{text-align:center;min-width:120px;}
        .wf-icon{font-size:2.8rem;margin-bottom:8px;}
        .wf-label{font-weight:700;font-size:1.2rem;color:#1e3a6b;}
        .wf-arrow{font-size:2.5rem;color:#6f9be0;}
        .wf-desc{margin-top:24px;padding:18px;background:#e5efff;border-radius:24px;color:#1d3d6d;}

        /* 科普FAQ区块 (简短) */
        .faq-light{background:#ffffff;border-radius:28px;padding:28px 32px;margin:30px 0;}
        .faq-light h3{font-size:1.7rem;margin-bottom:20px;}
        .faq-item{margin-bottom:20px;border-bottom:1px solid #e1e9f3;padding-bottom:16px;}
        .faq-question{font-weight:700;font-size:1.2rem;margin-bottom:8px;}
        .faq-answer{color:#2e4e72;}

        /* 引导卡片 */
        .guide-row{display:flex;gap:20px;margin:30px 0;}
        .guide-card{background:#eef4fe;border-radius:28px;padding:22px 28px;flex:1;display:flex;align-items:center;justify-content:space-between;text-decoration:none;color:#1a2f4a;transition:0.15s;}
        .guide-card:hover{background:#dfeafc;}
        .guide-card span{font-size:1.4rem;font-weight:650;}
        .guide-arrow{font-size:2rem;color:#1e5fd9;}

        /* 下载召唤 */
        .download-cta{background:#1e5fd9;border-radius:60px;padding:28px 36px;margin:40px 0;display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:20px;}
        .download-cta p{color:white;font-size:1.8rem;font-weight:650;}
        .cta-big-btn{background:white;color:#1e5fd9;padding:16px 40px;border-radius:60px;font-weight:700;font-size:1.3rem;text-decoration:none;box-shadow:0 8px 22px rgba(0,0,0,0.1);}

        .footer{margin-top:50px;padding:28px 0;border-top:1px solid rgba(0,0,0,0.05);color:#5c6f8c;display:flex;justify-content:space-between;flex-wrap:wrap;}

        .fixed-download{position:fixed;bottom:30px;right:30px;z-index:999;background:#1e5fd9;color:white;width:64px;height:64px;border-radius:40px;display:flex;align-items:center;justify-content:center;box-shadow:0 12px 28px rgba(30,95,217,0.4);text-decoration:none;font-size:28px;font-weight:700;transition:0.2s;}
        .fixed-download:hover{transform:scale(1.08);background:#0f4ab8;}

        @media (max-width:720px){
            .nav-bar{flex-direction:column;gap:15px;}
            .page-header h1{font-size:2rem;}
            .concept-grid{grid-template-columns:1fr;}
            .workflow-steps{flex-direction:column;}
            .wf-arrow{transform:rotate(90deg);}
            .download-cta p{font-size:1.5rem;}
        }