:root{
            --safe-primary:#0b5fff;
            --safe-primary-dark:#0847c4;
            --safe-accent:#00d4aa;
            --safe-dark:#0d1b2a;
            --safe-darker:#08111c;
            --safe-text:#1f2937;
            --safe-muted:#5b6b7c;
            --safe-bg:#ffffff;
            --safe-bg-alt:#f5f8ff;
            --safe-border:#e6ecf5;
            --safe-radius:20px;
            --safe-shadow:0 12px 30px rgba(11,95,255,.08);
            --safe-transition:.3s cubic-bezier(.4,0,.2,1);
            --font-sans:'Inter','PingFang SC','Microsoft YaHei','Segoe UI',sans-serif;
        }
        *{margin:0;padding:0;box-sizing:border-box}
        html{scroll-behavior:smooth}
        body{font-family:var(--font-sans);color:var(--safe-text);background:var(--safe-bg);line-height:1.6;overflow-x:hidden}
        a{text-decoration:none;color:inherit}
        img{max-width:100%;display:block}
        .site{display:flex;flex-direction:column;min-height:100vh}
        .section-wrap{max-width:1200px;margin:0 auto;padding:0 24px}

        /* Header */
        .site-header{background:rgba(255,255,255,.9);backdrop-filter:blur(12px);position:sticky;top:0;z-index:100;border-bottom:1px solid var(--safe-border)}
        .nav-shell{display:flex;align-items:center;justify-content:space-between;max-width:1200px;margin:0 auto;padding:12px 24px;gap:20px}
        .brand{display:flex;align-items:center;gap:8px;font-weight:800;font-size:1.5rem;color:var(--safe-dark);}
        .brand img{height:40px;width:auto}
        .main-nav{display:flex;align-items:center;gap:28px}
        .main-nav a{font-weight:600;color:var(--safe-text);position:relative;padding:6px 0;transition:var(--safe-transition)}
        .main-nav a::after{content:"";position:absolute;left:0;bottom:0;width:0;height:2px;background:var(--safe-primary);transition:var(--safe-transition)}
        .main-nav a:hover::after,.main-nav a.active::after{width:100%}
        .main-nav a.active{color:var(--safe-primary)}
        .nav-actions{display:flex;align-items:center;gap:14px}
        .lang-button{display:flex;align-items:center;gap:6px;background:transparent;border:1px solid var(--safe-border);border-radius:40px;padding:8px 14px;cursor:pointer;font-weight:600;color:var(--safe-text);transition:var(--safe-transition)}
        .lang-button:hover{background:var(--safe-bg-alt);border-color:var(--safe-primary)}
        .lang-button img{width:18px;height:18px}
        .chevron{width:12px!important;height:8px!important;transition:transform .3s}
        .lang-menu{position:absolute;top:58px;right:24px;background:#fff;border:1px solid var(--safe-border);border-radius:14px;box-shadow:var(--safe-shadow);padding:8px 0;min-width:160px;display:flex;flex-direction:column;z-index:200}
        .lang-menu[hidden]{display:none}
        .lang-menu a{padding:10px 18px;font-weight:600;color:var(--safe-text);transition:background .2s}
        .lang-menu a:hover{background:var(--safe-bg-alt);color:var(--safe-primary)}
        .menu-button{display:none;background:none;border:none;cursor:pointer;width:32px;height:32px;flex-direction:column;justify-content:center;gap:5px}
        .menu-button span{display:block;width:22px;height:2px;background:var(--safe-text);border-radius:2px;transition:var(--safe-transition)}

        /* Hero */
        .hero{background:linear-gradient(145deg,#f0f6ff 0%,#ffffff 45%,#eef7ff 100%);padding:80px 0 70px;overflow:hidden}
        .hero-grid{display:grid;grid-template-columns:1.1fr .9fr;gap:50px;align-items:center}
        .hero-kicker{display:inline-block;background:rgba(11,95,255,.08);color:var(--safe-primary);font-weight:700;font-size:14px;padding:8px 18px;border-radius:40px;margin-bottom:18px;letter-spacing:.5px}
        .hero-heading{font-size:clamp(2.3rem,5vw,3.6rem);line-height:1.2;font-weight:800;color:var(--safe-dark);margin-bottom:20px}
        .hero-nowrap{display:block;white-space:nowrap}
        .hero-subline{display:block;color:var(--safe-primary);font-size:.8em;margin-top:8px}
        .hero-text{font-size:1.1rem;color:var(--safe-muted);max-width:560px;margin-bottom:26px}
        .hero-wordmark{height:48px;width:auto;margin-bottom:24px}
        .download-buttons{display:flex;flex-wrap:wrap;gap:14px}
        .download-button{display:inline-flex;align-items:center;gap:8px;background:var(--safe-dark);color:#fff;font-weight:600;padding:12px 22px;border-radius:50px;transition:var(--safe-transition);box-shadow:0 8px 20px rgba(13,27,42,.15)}
        .download-button:hover{background:var(--safe-primary);transform:translateY(-2px);box-shadow:0 12px 24px rgba(11,95,255,.25)}
        .download-button img{width:20px;height:20px}
        .hero-media img{border-radius:24px;box-shadow:0 30px 60px rgba(11,95,255,.12)}

        /* Trust badges */
        .trust-bar{background:var(--safe-darker);padding:22px 0;border-top:1px solid rgba(255,255,255,.05);border-bottom:1px solid rgba(255,255,255,.05)}
        .trust-grid{display:flex;flex-wrap:wrap;justify-content:space-between;gap:20px;align-items:center}
        .trust-item{color:#c7d4e4;display:flex;align-items:center;gap:10px;font-weight:600;font-size:15px}
        .trust-item .icon{width:34px;height:34px;border-radius:10px;background:rgba(0,212,170,.12);display:flex;align-items:center;justify-content:center;font-size:18px}

        /* Feature section */
        .feature-section{padding:90px 0}
        .feature-section h2{font-size:clamp(1.8rem,3.5vw,2.6rem);font-weight:800;color:var(--safe-dark);margin-bottom:40px;text-align:center;max-width:800px;margin-left:auto;margin-right:auto}
        .feature-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:28px}
        .feature-card{background:var(--safe-bg-alt);border:1px solid var(--safe-border);border-radius:var(--safe-radius);padding:32px 26px;transition:var(--safe-transition);display:flex;flex-direction:column;gap:16px}
        .feature-card:hover{transform:translateY(-6px);box-shadow:var(--safe-shadow);border-color:var(--safe-primary)}
        .feature-card img{width:52px;height:52px;object-fit:contain}
        .feature-card h3{font-size:1.4rem;font-weight:700;color:var(--safe-dark)}
        .feature-card p{color:var(--safe-muted);font-size:.98rem}
        .feature-icon{font-size:2.5rem;line-height:1;}

        /* Encryption flow */
        .encryption-flow{background:var(--safe-dark);padding:90px 0;color:#fff}
        .encryption-flow h2{font-size:clamp(1.8rem,3.5vw,2.6rem);font-weight:800;text-align:center;margin-bottom:50px}
        .flow-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:30px;counter-reset:step}
        .flow-step{background:rgba(255,255,255,.05);border:1px solid rgba(255,255,255,.1);border-radius:var(--safe-radius);padding:36px 24px;text-align:center;position:relative;transition:var(--safe-transition)}
        .flow-step:hover{background:rgba(255,255,255,.08);transform:translateY(-4px)}
        .flow-step .step-num{width:48px;height:48px;border-radius:50%;background:var(--safe-primary);display:flex;align-items:center;justify-content:center;font-weight:800;font-size:1.3rem;margin:0 auto 20px}
        .flow-step h3{font-size:1.3rem;font-weight:700;margin-bottom:12px;color:#fff}
        .flow-step p{color:#b8c7d9;font-size:.95rem}

        /* File vault */
        .file-vault{padding:90px 0;background:var(--safe-bg-alt)}
        .file-vault .section-wrap{display:grid;grid-template-columns:1fr 1fr;gap:50px;align-items:center}
        .file-vault-copy h2{font-size:clamp(1.8rem,3.5vw,2.6rem);font-weight:800;color:var(--safe-dark);margin-bottom:20px}
        .file-vault-copy p{color:var(--safe-muted);margin-bottom:16px;font-size:1.05rem}
        .file-vault-list{list-style:none;margin-top:26px}
        .file-vault-list li{display:flex;gap:12px;align-items:flex-start;margin-bottom:14px;font-weight:600;color:var(--safe-text)}
        .file-vault-list li::before{content:"🔒";flex-shrink:0;margin-top:2px}
        .file-vault-media img{border-radius:24px;box-shadow:var(--safe-shadow)}

        /* Global presence */
        .global-presence{padding:90px 0}
        .global-presence h2{font-size:clamp(1.8rem,3.5vw,2.6rem);font-weight:800;color:var(--safe-dark);text-align:center;margin-bottom:30px}
        .global-presence p{text-align:center;color:var(--safe-muted);max-width:700px;margin:0 auto 50px;font-size:1.05rem}
        .node-grid{display:flex;flex-wrap:wrap;justify-content:center;gap:14px}
        .node-pill{background:var(--safe-bg-alt);border:1px solid var(--safe-border);border-radius:40px;padding:10px 22px;font-weight:600;color:var(--safe-dark);display:flex;align-items:center;gap:8px;transition:var(--safe-transition)}
        .node-pill:hover{background:var(--safe-primary);color:#fff;border-color:var(--safe-primary);transform:translateY(-2px)}

        /* Testimonials */
        .voice-section{padding:90px 0;background:var(--safe-bg-alt)}
        .section-heading-row{display:flex;align-items:center;justify-content:space-between;margin-bottom:40px}
        .section-heading-row h2{font-size:clamp(1.8rem,3.5vw,2.6rem);font-weight:800;color:var(--safe-dark)}
        .arrow-pair span{display:inline-flex;width:44px;height:44px;border-radius:50%;background:#fff;border:1px solid var(--safe-border);align-items:center;justify-content:center;font-size:1.5rem;cursor:pointer;margin-left:10px;transition:var(--safe-transition)}
        .arrow-pair span:hover{background:var(--safe-primary);color:#fff;border-color:var(--safe-primary)}
        .testimonial-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:28px}
        .testimonial-card{background:#fff;border-radius:var(--safe-radius);padding:28px 24px;box-shadow:0 6px 18px rgba(0,0,0,.04);border:1px solid var(--safe-border)}
        .person{display:flex;align-items:center;gap:12px;margin-bottom:16px}
        .avatar-icon{width:44px;height:44px;border-radius:50%;background:var(--safe-bg-alt);display:flex;align-items:center;justify-content:center;font-size:24px;flex-shrink:0}
        .person strong{font-size:1.05rem;color:var(--safe-dark)}
        .testimonial-card p{color:var(--safe-muted);font-size:.95rem}

        /* Partner / Friend Links (创意友链) */
        .partner-section{padding:90px 0;background:var(--safe-bg)}
        .partner-section .section-wrap > h2{font-size:clamp(1.8rem,3.5vw,2.6rem);font-weight:800;color:var(--safe-dark);text-align:center;margin-bottom:20px}
        .partner-section .section-wrap > p{text-align:center;color:var(--safe-muted);max-width:600px;margin:0 auto 40px}
        .partner-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:20px}
        .partner-card{display:flex;flex-direction:column;align-items:center;gap:10px;background:var(--safe-bg-alt);border:1px solid var(--safe-border);border-radius:var(--safe-radius);padding:28px 20px;transition:var(--safe-transition);text-align:center}
        .partner-card:hover{transform:translateY(-6px);box-shadow:var(--safe-shadow);border-color:var(--safe-primary)}
        .partner-icon{font-size:2.5rem}
        .partner-name{font-weight:700;color:var(--safe-dark);font-size:1.1rem}
        .partner-desc{color:var(--safe-muted);font-size:.9rem}

        /* Download section */
        .download-section{padding:90px 0;background:linear-gradient(135deg,var(--safe-dark) 0%,#122a47 100%);color:#fff}
        .download-grid{display:grid;grid-template-columns:1fr 1fr;gap:50px;align-items:center}
        .download-copy h2{font-size:clamp(1.8rem,3.5vw,2.6rem);font-weight:800;margin-bottom:26px}
        .download-copy .download-button{background:#fff;color:var(--safe-dark);box-shadow:0 10px 30px rgba(0,0,0,.3)}
        .download-copy .download-button:hover{background:var(--safe-accent);color:var(--safe-dark)}
        .download-media img{border-radius:24px;box-shadow:0 30px 60px rgba(0,0,0,.3)}

        /* Footer */
        .site-footer{background:var(--safe-darker);color:#aebdce;padding:60px 0 20px}
        .footer-wrap{max-width:1200px;margin:0 auto;padding:0 24px}
        .footer-logo{display:flex;align-items:center;gap:8px;font-weight:800;font-size:1.5rem;color:#fff;margin-bottom:32px;}
        .footer-logo img{height:40px;margin-bottom:0;}
        .footer-cols{display:grid;grid-template-columns:repeat(auto-fit,minmax(180px,1fr));gap:32px;margin-bottom:40px}
        .footer-cols h2{font-size:1.1rem;font-weight:700;color:#fff;margin-bottom:16px}
        .footer-cols p{display:flex;flex-direction:column;gap:8px}
        .footer-cols a{color:#aebdce;transition:var(--safe-transition)}
        .footer-cols a:hover{color:var(--safe-primary)}
        .footer-cols .mail-link{color:var(--safe-accent)}
        .site-footer small{display:block;text-align:center;padding-top:20px;border-top:1px solid rgba(255,255,255,.08);color:#64748b;font-size:.85rem}

        /* Responsive */
        @media(max-width:900px){
            .hero-grid,.download-grid,.file-vault .section-wrap{grid-template-columns:1fr;text-align:center}
            .hero-text{margin-left:auto;margin-right:auto}
            .download-buttons{justify-content:center}
            .hero-media img{margin:0 auto}
            .file-vault-copy .file-vault-list{text-align:left}
        }
        @media(max-width:768px){
            .main-nav{display:none;position:absolute;top:64px;left:0;right:0;background:#fff;flex-direction:column;padding:20px;box-shadow:0 20px 40px rgba(0,0,0,.08);border-bottom:1px solid var(--safe-border);gap:12px}
            .main-nav.open{display:flex}
            .menu-button{display:flex}
            .nav-shell{flex-wrap:wrap}
            .trust-grid{justify-content:center;text-align:center}
        }