:root {
    --gradient: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    --blue: #2980FE;
    --blue-dark: #1768E8;
    --text: #172033;
    --muted: #647084;
    --line: #E5EAF2;
    --soft: #F6F8FC;
    --soft-blue: #F1F6FF;
    --white: #FFFFFF;
    --shadow: 0 18px 48px rgba(42, 68, 117, 0.12);
    --radius: 24px;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
    color: var(--text);
    background: #fff;
    line-height: 1.75;
    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(255,255,255,0.94);
    border-bottom: 1px solid rgba(229,234,242,0.9);
    backdrop-filter: blur(14px);
}
.header-inner { display: flex; align-items: center; justify-content: space-between; min-height: 68px; gap: 18px; }
.brand { display: inline-flex; align-items: center; gap: 10px; font-weight: 800; font-size: 20px; }
.logo-img { width: 38px; height: 38px; border-radius: 12px; object-fit: cover; box-shadow: 0 8px 18px rgba(41,128,254,0.18); }
.main-nav { display: none; width: 100%; flex-direction: column; gap: 6px; padding: 12px 0 18px; }
.main-nav a { color: #344059; font-size: 15px; padding: 10px 12px; border-radius: 14px; }
.main-nav a:hover { background: var(--soft-blue); color: var(--blue); }
.nav-toggle { position: absolute; opacity: 0; pointer-events: none; }
.nav-toggle-label { display: inline-flex; flex-direction: column; gap: 5px; width: 42px; height: 42px; align-items: center; justify-content: center; border: 1px solid var(--line); border-radius: 14px; }
.nav-toggle-label span { width: 18px; height: 2px; background: #25324A; border-radius: 2px; }
.nav-toggle:checked ~ .main-nav { display: flex; position: absolute; top: 68px; left: 16px; right: 16px; width: auto; background: #fff; border: 1px solid var(--line); border-radius: 20px; box-shadow: var(--shadow); padding: 12px; }
.section { padding: 64px 0; }
.section-soft { background: var(--soft); }
.section-head { max-width: 760px; margin: 0 auto 30px; text-align: center; }
.section-head h2, .content-page h2 { margin: 0 0 12px; font-size: clamp(26px, 5vw, 42px); line-height: 1.18; letter-spacing: -0.02em; }
.section-head p, .lead { color: var(--muted); margin: 0; }
.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: 700;
    box-shadow: 0 12px 26px rgba(41,128,254,0.26);
    transition: transform .2s ease, background .2s ease, box-shadow .2s ease;
}
.download-btn:hover { background: var(--blue-dark); transform: translateY(-2px); box-shadow: 0 16px 30px rgba(23,104,232,0.28); }
.link-more { color: var(--blue); font-weight: 700; display: inline-flex; margin-top: 14px; }
.badge, .category-badge { display: inline-flex; align-items: center; gap: 6px; color: var(--blue); background: #EAF2FF; border: 1px solid #D8E7FF; border-radius: 999px; padding: 6px 12px; font-size: 13px; font-weight: 700; }
.vpn-network-hero {
    position: relative;
    padding: 72px 0 54px;
    background: var(--gradient);
    color: #fff;
    overflow: hidden;
}
.vpn-network-hero:before,
.vpn-network-hero:after {
    content: "";
    position: absolute;
    inset: 0;
    background-image: radial-gradient(circle at 18% 24%, rgba(255,255,255,.26) 0 2px, transparent 3px), radial-gradient(circle at 78% 34%, rgba(255,255,255,.2) 0 2px, transparent 3px), linear-gradient(120deg, transparent 0 20%, rgba(255,255,255,.14) 20.2%, transparent 20.5% 44%, rgba(255,255,255,.12) 44.2%, transparent 44.6%);
    opacity: .65;
}
.vpn-network-hero:after { filter: blur(28px); opacity: .42; background: radial-gradient(circle at 65% 30%, rgba(255,255,255,.8), transparent 34%), radial-gradient(circle at 20% 70%, rgba(255,255,255,.45), transparent 30%); }
.hero-grid { position: relative; z-index: 1; display: grid; gap: 34px; align-items: center; }
.hero-copy h1 { margin: 14px 0 16px; font-size: clamp(36px, 9vw, 64px); line-height: 1.05; letter-spacing: -0.04em; }
.hero-copy p { margin: 0 0 22px; color: rgba(255,255,255,.9); font-size: 17px; }
.hero-tags { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 20px; }
.hero-tags span { border: 1px solid rgba(255,255,255,.28); background: rgba(255,255,255,.13); border-radius: 999px; padding: 8px 12px; font-size: 13px; }
.hero-visual { position: relative; min-height: 330px; display: grid; place-items: center; }
.hero-visual .visual-card { background: rgba(255,255,255,.16); border: 1px solid rgba(255,255,255,.25); border-radius: 32px; padding: 20px; box-shadow: 0 24px 80px rgba(20,32,70,.22); backdrop-filter: blur(10px); }
.hero-visual img { max-height: 420px; object-fit: contain; }
.float-card { position: absolute; padding: 10px 14px; border-radius: 16px; background: rgba(255,255,255,.92); color: #20304B; box-shadow: 0 12px 32px rgba(20,32,70,.18); font-size: 13px; font-weight: 800; }
.float-card.one { top: 12px; left: 0; }
.float-card.two { top: 48px; right: 4px; }
.float-card.three { bottom: 42px; left: 8px; }
.float-card.four { bottom: 12px; right: 18px; }
.node-overview { margin-top: -32px; position: relative; z-index: 2; }
.overview-grid { display: grid; gap: 16px; }
.node-card, .feature-card, .risk-card, .faq-item, .step-card, .info-card {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 22px;
    box-shadow: 0 12px 30px rgba(28, 43, 74, .06);
}
.node-card .tag { color: var(--blue); font-weight: 800; font-size: 13px; }
.node-card h3, .feature-card h3, .risk-card h3, .step-card h3, .info-card h3 { margin: 8px 0 8px; font-size: 20px; }
.node-card p, .feature-card p, .risk-card p, .step-card p, .info-card p { margin: 0; color: var(--muted); }
.split { display: grid; gap: 28px; align-items: center; }
.panel-img { border-radius: 32px; overflow: hidden; background: linear-gradient(145deg, #F7FAFF, #EAF2FF); border: 1px solid var(--line); padding: 18px; box-shadow: var(--shadow); }
.panel-img img { margin: auto; max-height: 430px; object-fit: contain; }
.check-list { display: grid; gap: 10px; margin: 18px 0; padding: 0; list-style: none; }
.check-list li { display: flex; gap: 10px; color: #39465E; }
.check-list li:before { content: ""; flex: 0 0 9px; width: 9px; height: 9px; border-radius: 50%; background: var(--blue); margin-top: 11px; }
.global-nodes-section { position: relative; background: #fff; }
.map-panel { position: relative; overflow: hidden; border-radius: 32px; padding: 30px; background: linear-gradient(145deg, #F8FBFF, #EEF5FF); border: 1px solid var(--line); }
.map-panel:before { content: ""; position: absolute; inset: 18px; background-image: radial-gradient(circle at 22% 35%, #2980FE 0 4px, transparent 5px), radial-gradient(circle at 58% 28%, #7B4EF1 0 4px, transparent 5px), radial-gradient(circle at 78% 62%, #B84DDA 0 4px, transparent 5px), linear-gradient(100deg, transparent 22%, rgba(41,128,254,.16) 22.3%, transparent 22.8% 58%, rgba(123,78,241,.16) 58.3%, transparent 58.8%); opacity: .9; }
.map-panel > * { position: relative; z-index: 1; }
.speed-lines { display: grid; gap: 12px; margin: 20px 0; }
.speed-line { padding: 14px 16px; background: #fff; border: 1px solid var(--line); border-radius: 16px; display: flex; justify-content: space-between; color: #40506A; }
.privacy-panel { background: #fff; border: 1px solid var(--line); border-radius: 32px; padding: 28px; box-shadow: var(--shadow); }
.privacy-tags { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 18px; }
.privacy-tags span { background: var(--soft-blue); color: var(--blue); border-radius: 999px; padding: 8px 12px; font-weight: 700; font-size: 13px; }
.three-grid, .risk-grid, .faq-grid, .page-card-grid { display: grid; gap: 16px; }
.protocol-panel { background: #121B33; color: #fff; border-radius: 32px; padding: 28px; overflow: hidden; position: relative; }
.protocol-panel p { color: rgba(255,255,255,.76); }
.protocol-panel .feature-card { background: rgba(255,255,255,.08); border-color: rgba(255,255,255,.14); box-shadow: none; }
.protocol-panel .feature-card p { color: rgba(255,255,255,.72); }
.process-steps { display: grid; gap: 14px; counter-reset: step; }
.step-card { position: relative; padding-left: 72px; }
.step-card:before { counter-increment: step; content: counter(step); position: absolute; left: 22px; top: 24px; width: 34px; height: 34px; border-radius: 12px; background: var(--blue); color: #fff; display: grid; place-items: center; font-weight: 800; }
.risk-card { border-left: 4px solid var(--blue); }
.risk-card strong { color: #25324A; display: block; margin-top: 10px; }
.cta-section { background: var(--gradient); color: #fff; text-align: center; padding: 62px 0; }
.cta-section p { color: rgba(255,255,255,.86); max-width: 640px; margin: 0 auto 22px; }
.page-hero { padding: 54px 0 34px; background: linear-gradient(180deg, #F7FAFF 0%, #FFFFFF 100%); }
.page-hero h1 { margin: 14px 0 12px; font-size: clamp(32px, 8vw, 54px); line-height: 1.1; letter-spacing: -0.03em; }
.content-page { padding: 36px 0 70px; }
.content-layout { display: grid; gap: 24px; }
.article-panel { background: #fff; border: 1px solid var(--line); border-radius: 30px; padding: 24px; box-shadow: var(--shadow); }
.article-panel h2 { font-size: clamp(24px, 5vw, 34px); }
.article-panel h3 { margin-top: 28px; font-size: 22px; }
.article-panel p { color: #4B586E; }
.side-panel { display: grid; gap: 16px; align-self: start; }
.notice-box { background: var(--soft-blue); border: 1px solid #DDEAFF; border-radius: 22px; padding: 20px; color: #43516A; }
.page-download { margin-top: 24px; }
.steps-list { margin: 18px 0; padding-left: 22px; color: #43516A; }
.steps-list li { margin: 8px 0; }
.faq-list { display: grid; gap: 14px; }
.faq-item h2, .faq-item h3 { margin: 0 0 8px; font-size: 20px; }
.faq-item p { margin: 0; color: var(--muted); }
.download-page .single-download-card { text-align: center; max-width: 820px; margin: 0 auto; }
.download-page .single-download-card .download-btn { margin: 16px 0 22px; }
.site-footer { background: #101828; color: rgba(255,255,255,.78); padding: 48px 0 22px; }
.footer-grid { display: grid; gap: 26px; }
.footer-brand { display: flex; gap: 10px; align-items: center; color: #fff; font-size: 20px; font-weight: 800; }
.footer-brand img { width: 36px; height: 36px; border-radius: 10px; object-fit: cover; }
.site-footer h3 { color: #fff; margin: 0 0 12px; font-size: 16px; }
.site-footer a { display: block; margin: 7px 0; color: rgba(255,255,255,.72); }
.site-footer a:hover { color: #fff; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,.1); margin-top: 28px; padding-top: 18px; font-size: 13px; color: rgba(255,255,255,.58); }
@media (min-width: 680px) {
    .overview-grid { grid-template-columns: repeat(2, 1fr); }
    .three-grid, .risk-grid, .faq-grid, .page-card-grid { grid-template-columns: repeat(2, 1fr); }
    .footer-grid { grid-template-columns: repeat(2, 1fr); }
    .process-steps { grid-template-columns: repeat(2, 1fr); }
}
@media (min-width: 960px) {
    .header-inner { min-height: 76px; }
    .main-nav { display: flex; width: auto; flex-direction: row; align-items: center; gap: 4px; padding: 0; }
    .nav-toggle-label { display: none; }
    .nav-toggle:checked ~ .main-nav { position: static; width: auto; padding: 0; border: 0; box-shadow: none; }
    .hero-grid { grid-template-columns: 1.02fr .98fr; }
    .vpn-network-hero { padding: 92px 0 76px; }
    .overview-grid { grid-template-columns: repeat(4, 1fr); }
    .split { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 46px; }
    .split.reverse .panel-copy { order: 2; }
    .split.reverse .panel-img { order: 1; }
    .three-grid { grid-template-columns: repeat(3, 1fr); }
    .risk-grid { grid-template-columns: repeat(3, 1fr); }
    .footer-grid { grid-template-columns: 1.4fr 1fr 1fr 1fr; }
    .content-layout { grid-template-columns: minmax(0, 1fr) 320px; align-items: start; }
    .article-panel { padding: 34px; }
    .section { padding: 82px 0; }
}