:root{
    --gradient: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    --blue:#2980FE;
    --blue-dark:#1768E8;
    --text:#1E293B;
    --muted:#64748B;
    --light:#F6F8FC;
    --line:#E2E8F0;
    --panel:#FFFFFF;
    --deep:#0F172A;
    --shadow:0 18px 45px rgba(15,23,42,.08);
    --radius:24px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
    margin:0;
    font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Microsoft YaHei",Arial,sans-serif;
    color:var(--text);
    background:#fff;
    line-height:1.7;
    overflow-x:hidden;
}
a{color:inherit;text-decoration:none}
img{max-width:100%;height:auto;display:block}
.container{width:min(1120px,calc(100% - 32px));margin:0 auto}
.site-header{
    position:sticky;top:0;z-index:20;background:rgba(255,255,255,.92);
    backdrop-filter:blur(16px);border-bottom:1px solid rgba(226,232,240,.8)
}
.header-inner{min-height:68px;display:flex;align-items:center;justify-content:space-between;gap:18px}
.logo{display:flex;align-items:center;gap:10px;font-weight:800;color:var(--deep);font-size:18px;white-space:nowrap}
.logo img{width:36px;height:36px;border-radius:12px;object-fit:cover}
.site-nav{display:none;position:absolute;top:68px;left:16px;right:16px;background:#fff;border:1px solid var(--line);border-radius:20px;box-shadow:var(--shadow);padding:12px}
.site-nav.open{display:grid;gap:4px}
.site-nav a{padding:10px 12px;border-radius:12px;color:var(--muted);font-size:14px}
.site-nav a:hover,.site-nav a.active{color:var(--blue);background:#F0F6FF}
.nav-download{font-weight:700}
.nav-toggle{border:1px solid var(--line);background:#fff;border-radius:12px;padding:8px 12px;color:var(--text)}
main{min-height:70vh}
.download-btn{
    display:inline-flex;align-items:center;justify-content:center;min-height:48px;padding:0 28px;
    border-radius:999px;background:var(--blue);color:#fff;font-weight:800;box-shadow:0 14px 28px rgba(41,128,254,.24);
    transition:transform .2s ease,background .2s ease,box-shadow .2s ease;white-space:nowrap
}
.download-btn:hover{background:var(--blue-dark);transform:translateY(-2px);box-shadow:0 18px 36px rgba(23,104,232,.28)}
.badge,.category-badge{display:inline-flex;align-items:center;gap:8px;padding:7px 12px;border-radius:999px;background:#EEF5FF;color:var(--blue);font-weight:800;font-size:13px}
.section{padding:64px 0}
.section-soft{background:var(--light)}
.section-title{font-size:30px;line-height:1.22;margin:0 0 14px;color:var(--deep);letter-spacing:-.02em}
.section-desc{color:var(--muted);margin:0 0 24px;max-width:760px}
.text-link{color:var(--blue);font-weight:800;border-bottom:1px solid rgba(41,128,254,.28)}
.lead{font-size:18px;color:#EAF2FF;max-width:620px;margin:16px 0 24px}
.vpn-network-hero{position:relative;overflow:hidden;background:var(--gradient);color:#fff;padding:72px 0 54px}
.vpn-network-hero:before{content:"";position:absolute;inset:0;background:radial-gradient(circle at 12% 20%,rgba(255,255,255,.24),transparent 24%),radial-gradient(circle at 82% 12%,rgba(255,255,255,.2),transparent 22%),linear-gradient(135deg,rgba(255,255,255,.16) 1px,transparent 1px);background-size:auto,auto,36px 36px;opacity:.85}
.hero-grid{position:relative;display:grid;gap:34px;align-items:center}
.hero-copy h1{font-size:40px;line-height:1.12;margin:12px 0 0;letter-spacing:-.04em}
.hero-tags{display:flex;gap:10px;flex-wrap:wrap;margin-top:24px}
.hero-tags span{background:rgba(255,255,255,.16);border:1px solid rgba(255,255,255,.24);border-radius:999px;padding:7px 12px;color:#fff;font-size:13px}
.hero-visual{position:relative;background:rgba(255,255,255,.14);border:1px solid rgba(255,255,255,.28);border-radius:32px;padding:24px;box-shadow:0 26px 70px rgba(22,32,91,.28)}
.hero-visual img{border-radius:24px;margin:auto;max-height:420px;object-fit:contain}
.float-card{position:absolute;background:rgba(255,255,255,.94);color:var(--deep);border-radius:16px;padding:10px 14px;font-size:13px;font-weight:800;box-shadow:0 14px 30px rgba(15,23,42,.14)}
.float-card.one{left:16px;top:18px}.float-card.two{right:16px;top:36px}.float-card.three{left:24px;bottom:28px}.float-card.four{right:22px;bottom:18px}
.node-overview{margin-top:-28px;position:relative;z-index:2}
.node-grid,.card-grid{display:grid;gap:16px}
.node-card,.feature-card,.info-card,.risk-card,.faq-item,.step-card,.side-card{background:var(--panel);border:1px solid var(--line);border-radius:var(--radius);padding:22px;box-shadow:0 12px 32px rgba(15,23,42,.05)}
.node-card strong{display:inline-flex;color:var(--blue);background:#EEF5FF;border-radius:999px;padding:4px 10px;font-size:12px;margin-bottom:10px}
.node-card h3,.feature-card h3,.info-card h3,.risk-card h3,.step-card h3{margin:0 0 8px;color:var(--deep);font-size:20px}
.node-card p,.feature-card p,.info-card p,.risk-card p,.step-card p{margin:0 0 12px;color:var(--muted)}
.split-section{display:grid;gap:28px;align-items:center}
.visual-panel{background:#fff;border:1px solid var(--line);border-radius:32px;padding:22px;box-shadow:var(--shadow);position:relative;overflow:hidden}
.visual-panel:before{content:"";position:absolute;inset:auto -60px -90px auto;width:180px;height:180px;border-radius:50%;background:rgba(41,128,254,.1)}
.visual-panel img{position:relative;border-radius:24px;margin:auto;max-height:360px;object-fit:contain}
.check-list,.plain-list{padding:0;margin:18px 0 20px;list-style:none;display:grid;gap:10px}
.check-list li,.plain-list li{position:relative;padding-left:26px;color:var(--muted)}
.check-list li:before{content:"";position:absolute;left:0;top:.68em;width:9px;height:9px;border-radius:50%;background:var(--blue);box-shadow:0 0 0 5px #EAF3FF}
.global-nodes-section{background:#F8FAFF;position:relative;overflow:hidden}
.global-nodes-section:before{content:"";position:absolute;inset:20px 0;background:radial-gradient(circle at 24% 40%,rgba(41,128,254,.16),transparent 18%),radial-gradient(circle at 72% 36%,rgba(123,78,241,.13),transparent 18%);pointer-events:none}
.map-panel{position:relative;background:#fff;border:1px solid var(--line);border-radius:32px;padding:24px;box-shadow:var(--shadow)}
.map-line{height:6px;border-radius:999px;background:linear-gradient(90deg,#DCEBFF,#2980FE,#A6B7FF,#E9D7FF);margin:20px 0}
.node-pills{display:flex;flex-wrap:wrap;gap:10px}.node-pills span{padding:8px 12px;border-radius:999px;background:#F1F5F9;color:#334155;font-size:13px}
.speed-lines{display:grid;gap:12px;margin-top:18px}.speed-line{background:#fff;border:1px solid var(--line);border-radius:16px;padding:14px}.speed-line b{display:block;color:var(--deep)}.speed-bar{height:8px;background:#EAF3FF;border-radius:99px;margin-top:10px;overflow:hidden}.speed-bar span{display:block;height:100%;background:var(--blue);border-radius:99px}
.privacy-panel{background:#fff;border:1px solid var(--line);border-radius:32px;padding:24px;box-shadow:var(--shadow)}
.privacy-tags{display:flex;flex-wrap:wrap;gap:10px;margin-top:16px}.privacy-tags span{background:#F8FAFC;border:1px solid var(--line);border-radius:999px;padding:8px 12px;color:var(--muted);font-weight:700}
.process-steps{display:grid;gap:16px;counter-reset:steps}.step-card{position:relative;padding-left:68px}.step-card:before{counter-increment:steps;content:counter(steps);position:absolute;left:22px;top:22px;width:32px;height:32px;border-radius:12px;background:var(--blue);color:#fff;display:grid;place-items:center;font-weight:900}
.risk-grid{display:grid;gap:16px}.risk-card{border-left:4px solid var(--blue)}.risk-card small{display:block;color:var(--blue);font-weight:800;margin-top:10px}
.faq-list{display:grid;gap:14px}.faq-item h3{margin:0 0 8px;color:var(--deep);font-size:18px}.faq-item p{margin:0;color:var(--muted)}
.cta-section{background:var(--gradient);color:#fff;text-align:center;position:relative;overflow:hidden}.cta-section:before{content:"";position:absolute;inset:0;background:radial-gradient(circle at 50% 0,rgba(255,255,255,.28),transparent 28%)}.cta-section .container{position:relative}.cta-section h2{font-size:30px;line-height:1.24;margin:0 0 12px}.cta-section p{margin:0 auto 22px;color:#EEF4FF;max-width:720px}
.page-hero{padding:54px 0 28px;background:linear-gradient(180deg,#F4F7FF 0%,#fff 100%)}
.page-hero h1{font-size:34px;line-height:1.18;margin:14px 0 12px;color:var(--deep);letter-spacing:-.03em}.page-hero p{max-width:820px;color:var(--muted);margin:0}
.article-layout{display:grid;gap:24px;align-items:start}.article-card{background:#fff;border:1px solid var(--line);border-radius:28px;padding:24px;box-shadow:var(--shadow)}.article-card h2{margin:0 0 12px;color:var(--deep)}.article-card p{color:var(--muted);margin:0 0 16px}.article-card p:last-child{margin-bottom:0}.article-card.alt{background:#F8FAFC}.article-card.gradient-top{border-top:5px solid var(--blue)}
.page-actions{margin-top:22px}.hint-box{background:#F8FAFC;border:1px solid var(--line);border-radius:22px;padding:18px;margin-top:18px}.hint-box strong{color:var(--deep)}.hint-box ul{margin:10px 0 0;padding-left:20px;color:var(--muted)}
.two-col{display:grid;gap:16px}.three-col{display:grid;gap:16px}.number-list{display:grid;gap:14px;margin-top:18px}.number-item{display:flex;gap:14px;background:#fff;border:1px solid var(--line);border-radius:20px;padding:16px}.number-item span{flex:0 0 34px;height:34px;border-radius:12px;background:#EEF5FF;color:var(--blue);display:grid;place-items:center;font-weight:900}.number-item h3{margin:0 0 4px;font-size:17px}.number-item p{margin:0;color:var(--muted)}
.download-panel{text-align:center;background:#fff;border:1px solid var(--line);border-radius:32px;padding:30px;box-shadow:var(--shadow)}
.site-footer{background:#0F172A;color:#CBD5E1;padding:44px 0 22px}.footer-grid{display:grid;gap:24px}.footer-brand{font-size:22px;color:#fff;font-weight:900;margin-bottom:8px}.site-footer h3{margin:0 0 10px;color:#fff;font-size:16px}.site-footer a{display:block;color:#CBD5E1;margin:8px 0}.site-footer a:hover{color:#fff}.footer-bottom{border-top:1px solid rgba(255,255,255,.12);margin-top:28px;padding-top:18px;display:flex;gap:10px;flex-direction:column;font-size:13px;color:#94A3B8}
@media (min-width:700px){
    .node-grid{grid-template-columns:repeat(2,1fr)}.card-grid,.risk-grid,.two-col{grid-template-columns:repeat(2,1fr)}.three-col{grid-template-columns:repeat(3,1fr)}.process-steps{grid-template-columns:repeat(2,1fr)}.footer-grid{grid-template-columns:1.4fr 1fr 1fr 1fr}.footer-bottom{flex-direction:row;justify-content:space-between}
}
@media (min-width:960px){
    .nav-toggle{display:none}.site-nav{display:flex;position:static;align-items:center;gap:4px;background:transparent;border:none;border-radius:0;box-shadow:none;padding:0}.site-nav a{padding:9px 10px}.hero-grid,.split-section,.article-layout{grid-template-columns:1.04fr .96fr}.hero-copy h1{font-size:58px}.section{padding:82px 0}.section-title{font-size:40px}.page-hero h1{font-size:46px}.node-grid{grid-template-columns:repeat(4,1fr)}.process-steps{grid-template-columns:repeat(3,1fr)}.risk-grid{grid-template-columns:repeat(4,1fr)}.article-layout.wide{grid-template-columns:1fr}.reverse .visual-panel{order:-1}.side-card{position:sticky;top:92px}.cta-section h2{font-size:42px}
}
@media (max-width:420px){
    .container{width:min(100% - 24px,1120px)}.hero-copy h1{font-size:34px}.page-hero h1{font-size:30px}.float-card{position:static;display:inline-flex;margin:6px 6px 0 0}.download-btn{width:100%;padding:0 18px}.hero-visual{padding:16px}.section{padding:50px 0}.step-card{padding-left:60px}
}