:root {
    --blue: #2980FE;
    --blue-dark: #1768E8;
    --text: #202A3A;
    --muted: #667085;
    --line: #E7ECF5;
    --soft: #F5F7FB;
    --soft-blue: #EEF5FF;
    --gradient: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    --radius: 24px;
    --shadow: 0 18px 46px rgba(39, 56, 110, .12);
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", Arial, sans-serif;
    color: var(--text);
    background: #fff;
    line-height: 1.72;
    overflow-x: hidden;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
.container { width: min(1120px, calc(100% - 32px)); margin: 0 auto; }
.site-header {
    position: sticky;
    top: 0;
    z-index: 50;
    background: rgba(255,255,255,.94);
    backdrop-filter: blur(14px);
    border-bottom: 1px solid var(--line);
}
.header-inner { min-height: 68px; display: flex; align-items: center; justify-content: space-between; gap: 14px; }
.brand { display: inline-flex; align-items: center; gap: 10px; font-weight: 800; font-size: 18px; color: #1D2B4F; }
.logo { width: 38px; height: 38px; border-radius: 12px; object-fit: cover; box-shadow: 0 8px 18px rgba(41,128,254,.18); }
.site-nav { display: none; width: 100%; flex-direction: column; gap: 8px; padding: 0 0 16px; }
.site-nav.open { display: flex; }
.site-nav a { color: #344054; font-weight: 600; padding: 10px 12px; border-radius: 12px; }
.site-nav a:hover { background: var(--soft-blue); color: var(--blue); }
.menu-toggle { border: 1px solid var(--line); background: #fff; color: #1D2B4F; width: 42px; height: 42px; border-radius: 14px; font-size: 22px; }
.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 30px rgba(41,128,254,.28);
    transition: transform .2s ease, background .2s ease, box-shadow .2s ease;
}
.download-btn:hover { background: var(--blue-dark); transform: translateY(-2px); box-shadow: 0 18px 38px rgba(23,104,232,.32); }
.section { padding: 64px 0; }
.section-soft { background: var(--soft); }
.section-title { max-width: 760px; margin: 0 auto 32px; text-align: center; }
.section-title .eyebrow, .eyebrow { color: var(--blue); font-weight: 800; font-size: 14px; letter-spacing: .06em; }
h1, h2, h3 { line-height: 1.22; margin: 0 0 14px; color: #17213A; }
h1 { font-size: clamp(34px, 7vw, 60px); letter-spacing: -1.4px; }
h2 { font-size: clamp(26px, 4vw, 40px); letter-spacing: -.8px; }
h3 { font-size: 20px; }
p { margin: 0 0 16px; color: var(--muted); }
.text-link { color: var(--blue); font-weight: 800; }
.badge, .category-badge { display: inline-flex; align-items: center; gap: 8px; padding: 7px 12px; border-radius: 999px; background: #EAF3FF; color: var(--blue); font-size: 13px; font-weight: 800; }
.vpn-network-hero {
    position: relative;
    overflow: hidden;
    color: #fff;
    background: var(--gradient);
    padding: 72px 0 52px;
}
.vpn-network-hero:before {
    content: "";
    position: absolute;
    inset: 0;
    background:
        radial-gradient(circle at 18% 24%, rgba(255,255,255,.24), transparent 24%),
        radial-gradient(circle at 78% 18%, rgba(255,255,255,.18), transparent 20%),
        linear-gradient(135deg, rgba(255,255,255,.12) 0 1px, transparent 1px 70px);
    opacity: .9;
}
.hero-grid { position: relative; display: grid; gap: 36px; align-items: center; }
.hero-copy p, .vpn-network-hero h1 { color: #fff; }
.hero-copy p { font-size: 17px; max-width: 660px; opacity: .92; }
.hero-tags { display: flex; flex-wrap: wrap; gap: 10px; margin: 22px 0 28px; }
.hero-tags span { padding: 8px 12px; border-radius: 999px; background: rgba(255,255,255,.16); border: 1px solid rgba(255,255,255,.24); color: #fff; font-weight: 700; font-size: 13px; }
.hero-visual { position: relative; min-height: 320px; display: grid; place-items: center; }
.hero-device { width: min(430px, 92%); border-radius: 34px; box-shadow: 0 28px 80px rgba(20, 27, 83, .28); }
.float-card { position: absolute; background: rgba(255,255,255,.92); color: #1D2B4F; border: 1px solid rgba(255,255,255,.6); box-shadow: var(--shadow); border-radius: 18px; padding: 10px 14px; font-weight: 800; font-size: 13px; }
.float-card.one { top: 16px; left: 10px; }
.float-card.two { top: 46px; right: 6px; }
.float-card.three { bottom: 54px; left: 0; }
.float-card.four { bottom: 14px; right: 22px; }
.node-overview { margin-top: -30px; position: relative; z-index: 4; }
.node-grid, .feature-grid, .policy-grid, .risk-grid, .faq-grid { display: grid; gap: 18px; }
.node-card, .feature-card, .policy-card, .risk-card, .faq-item, .panel, .side-card {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 24px;
    box-shadow: 0 12px 34px rgba(30,44,90,.06);
}
.node-card { position: relative; overflow: hidden; }
.node-card:before { content:""; position:absolute; left:24px; top:0; width:52px; height:4px; background: var(--blue); border-radius: 0 0 999px 999px; }
.node-card strong { display:block; font-size: 21px; margin: 12px 0 8px; color: #17213A; }
.service-split { display: grid; gap: 28px; align-items: center; }
.image-panel { background: linear-gradient(180deg, #F7FAFF, #FFFFFF); border: 1px solid var(--line); border-radius: 32px; padding: 22px; box-shadow: var(--shadow); }
.bullet-list, .check-list { padding: 0; margin: 18px 0; list-style: none; display: grid; gap: 10px; }
.bullet-list li, .check-list li { position: relative; padding-left: 26px; color: #475467; }
.bullet-list li:before, .check-list li:before { content:""; position:absolute; left:0; top:.72em; width:10px; height:10px; border-radius:50%; background: var(--blue); box-shadow: 0 0 0 5px #EAF3FF; }
.global-nodes-section { background: #F6F8FC; position: relative; overflow: hidden; }
.global-nodes-section:before { content:""; position:absolute; inset: 40px 0 auto; height: 280px; background: radial-gradient(circle at 20% 40%, rgba(41,128,254,.18), transparent 18%), radial-gradient(circle at 80% 35%, rgba(123,78,241,.16), transparent 20%); pointer-events:none; }
.map-panel { position: relative; background: #fff; border: 1px solid var(--line); border-radius: 32px; padding: 24px; overflow: hidden; box-shadow: var(--shadow); }
.map-panel:before { content:""; position:absolute; inset:0; background-image: radial-gradient(#CBD7FF 1.2px, transparent 1.2px); background-size: 22px 22px; opacity:.55; }
.map-panel > * { position: relative; }
.line-card { display: grid; gap: 12px; margin-top: 18px; }
.line-card span { display:flex; justify-content:space-between; gap: 12px; padding: 12px 14px; border-radius: 14px; background: #F5F8FF; color:#475467; font-weight:700; }
.high-speed-section { background: linear-gradient(180deg, #F4F8FF, #FFFFFF); }
.speed-bars { display: grid; gap: 12px; margin: 18px 0; }
.speed-bars div { height: 12px; border-radius: 999px; background: #DFE8F9; overflow: hidden; }
.speed-bars i { display:block; height: 100%; border-radius: inherit; background: var(--blue); }
.privacy-protection-section .privacy-panel { display: grid; gap: 18px; }
.security-tags { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 16px; }
.security-tags span { background: #F2F6FF; color: #33507A; padding: 8px 12px; border-radius: 999px; font-weight: 700; }
.no-log-policy-section .policy-card { border-top: 4px solid var(--blue); }
.multi-device-section { background: #fff; }
.device-row { display: grid; grid-template-columns: 1fr; gap: 14px; margin-top: 20px; }
.device-item { padding: 16px; border: 1px solid var(--line); border-radius: 18px; background: #F8FAFD; }
.encryption-protocol-section { background: #F7F9FE; }
.tech-panel { background: #fff; border-radius: 30px; border: 1px solid var(--line); padding: 24px; box-shadow: var(--shadow); }
.protocol-stack { display:grid; gap: 12px; margin-top: 18px; }
.protocol-stack div { padding: 14px 16px; border-radius: 16px; border:1px solid var(--line); background: linear-gradient(90deg, #F8FAFF, #FFFFFF); }
.process-steps { display: grid; gap: 16px; counter-reset: step; }
.step-card { position:relative; background:#fff; border: 1px solid var(--line); border-radius: 22px; padding: 22px; box-shadow: 0 12px 30px rgba(30,44,90,.05); }
.step-card .step-no { width: 38px; height: 38px; border-radius: 14px; display:grid; place-items:center; background: var(--blue); color:#fff; font-weight:900; margin-bottom:12px; }
.risk-card { border-left: 4px solid var(--blue); }
.risk-card strong { display:block; color:#17213A; font-size: 18px; margin-bottom: 8px; }
.faq-item h3 { font-size: 18px; }
.cta-section { background: var(--gradient); color: #fff; text-align: center; padding: 64px 0; position: relative; overflow: hidden; }
.cta-section:before { content:""; position:absolute; inset:0; background: radial-gradient(circle at 22% 0, rgba(255,255,255,.22), transparent 24%), radial-gradient(circle at 88% 60%, rgba(255,255,255,.15), transparent 22%); }
.cta-section .container { position: relative; }
.cta-section h2, .cta-section p { color: #fff; }
.page-hero { padding: 58px 0 38px; background: linear-gradient(180deg, #F7FAFF, #FFFFFF); border-bottom: 1px solid var(--line); }
.page-hero .container { max-width: 940px; }
.page-layout { display: grid; gap: 26px; align-items: start; padding: 52px 0; }
.article-card { background: #fff; border: 1px solid var(--line); border-radius: 28px; padding: 24px; box-shadow: 0 14px 36px rgba(30,44,90,.06); }
.article-card h2 { font-size: 25px; margin-top: 8px; }
.info-list { display: grid; gap: 12px; margin: 18px 0; }
.info-list div { padding: 14px 16px; border-radius: 16px; background: #F8FAFD; border: 1px solid var(--line); }
.side-card { position: static; }
.side-card a { display:block; padding: 10px 0; color: var(--blue); font-weight: 800; border-bottom: 1px solid var(--line); }
.side-card a:last-child { border-bottom: 0; }
.download-page .download-action { margin: 28px 0; text-align: center; }
.install-steps { display: grid; gap: 14px; margin-top: 22px; }
.install-steps .step-card { display: grid; grid-template-columns: auto 1fr; gap: 14px; align-items: start; }
.site-footer { background: #111A2E; color: #C8D1E6; padding: 48px 0 24px; }
.site-footer p, .site-footer a { color: #C8D1E6; }
.footer-grid { display: grid; gap: 28px; }
.footer-grid h3 { color: #fff; font-size: 16px; }
.footer-grid a { display:block; padding: 5px 0; }
.footer-brand { display:flex; align-items:center; gap: 10px; color:#fff; font-weight:900; font-size: 20px; margin-bottom: 12px; }
.footer-brand img { width: 34px; height: 34px; border-radius: 10px; }
.footer-bottom { margin-top: 30px; padding-top: 18px; border-top: 1px solid rgba(255,255,255,.12); display: flex; flex-direction: column; gap: 8px; color: #AEB8D0; font-size: 14px; }
@media (min-width: 700px) {
    .node-grid, .feature-grid, .policy-grid, .faq-grid { grid-template-columns: repeat(2, 1fr); }
    .risk-grid { grid-template-columns: repeat(2, 1fr); }
    .process-steps { grid-template-columns: repeat(2, 1fr); }
    .device-row { grid-template-columns: repeat(3, 1fr); }
    .footer-grid { grid-template-columns: 1.5fr 1fr 1fr 1fr; }
    .footer-bottom { flex-direction: row; justify-content: space-between; }
}
@media (min-width: 980px) {
    .header-inner { min-height: 74px; }
    .menu-toggle { display: none; }
    .site-nav { display: flex; width: auto; flex-direction: row; align-items: center; padding: 0; gap: 2px; }
    .site-nav a { font-size: 14px; padding: 9px 10px; }
    .hero-grid, .service-split, .privacy-protection-section .privacy-panel, .page-layout { grid-template-columns: 1.05fr .95fr; }
    .hero-grid { gap: 56px; }
    .vpn-network-hero { padding: 96px 0 82px; }
    .node-grid { grid-template-columns: repeat(4, 1fr); }
    .policy-grid { grid-template-columns: repeat(3, 1fr); }
    .risk-grid { grid-template-columns: repeat(4, 1fr); }
    .process-steps { grid-template-columns: repeat(3, 1fr); }
    .side-card { position: sticky; top: 96px; }
    .reverse .image-panel { order: -1; }
}
@media (max-width: 480px) {
    .container { width: min(100% - 24px, 1120px); }
    .section { padding: 48px 0; }
    .node-card, .feature-card, .policy-card, .risk-card, .faq-item, .panel, .side-card, .article-card { padding: 20px; border-radius: 20px; }
    .download-btn { width: 100%; min-height: 50px; }
    .float-card { font-size: 12px; padding: 8px 10px; }
    .hero-visual { min-height: 280px; }
}