:root {
    --gradient: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    --blue: #2980FE;
    --blue-dark: #1768E8;
    --text: #1f2937;
    --muted: #64748b;
    --light: #f5f7fb;
    --line: #e5eaf2;
    --panel: #ffffff;
    --radius: 24px;
    --shadow: 0 18px 45px rgba(25, 45, 92, .10);
}
* { 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: 1.75;
    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: 30;
    background: rgba(255,255,255,.92);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid rgba(229,234,242,.8);
}
.header-inner { min-height: 72px; display: flex; align-items: center; justify-content: space-between; gap: 18px; }
.brand, .footer-brand { display: inline-flex; align-items: center; gap: 10px; font-weight: 800; color: #17233d; letter-spacing: .02em; }
.brand-logo, .footer-brand img { width: 38px; height: 38px; border-radius: 12px; object-fit: cover; box-shadow: 0 6px 18px rgba(41,128,254,.22); }
.site-nav { display: none; position: absolute; left: 16px; right: 16px; top: 72px; background: #fff; padding: 14px; border: 1px solid var(--line); border-radius: 18px; box-shadow: var(--shadow); }
.site-nav.is-open { display: grid; gap: 8px; }
.site-nav a { padding: 10px 12px; border-radius: 12px; color: #334155; font-size: 15px; }
.site-nav a.active, .site-nav a:hover { background: #eef5ff; color: var(--blue); }
.nav-download { border: 1px solid rgba(41,128,254,.25); }
.nav-toggle { border: 1px solid var(--line); background: #fff; color: #334155; border-radius: 999px; padding: 8px 14px; font-weight: 700; }
.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 0 26px;
    border-radius: 999px;
    background: var(--blue);
    color: #fff;
    font-weight: 800;
    box-shadow: 0 14px 28px rgba(41,128,254,.28);
    transition: background .2s ease, transform .2s ease, box-shadow .2s ease;
}
.download-btn:hover { background: var(--blue-dark); transform: translateY(-2px); box-shadow: 0 18px 34px rgba(23,104,232,.32); }
.text-link { color: var(--blue); font-weight: 700; }
.text-link:hover { color: var(--blue-dark); }
.badge, .category-badge { display: inline-flex; align-items: center; gap: 6px; padding: 6px 11px; border-radius: 999px; background: #eef5ff; color: var(--blue); font-weight: 800; font-size: 13px; }
.hero-tags, .tag-row { display: flex; flex-wrap: wrap; gap: 10px; margin: 18px 0 0; }
.hero-tags span, .tag-row span, .status-pill { border-radius: 999px; padding: 7px 11px; background: rgba(255,255,255,.16); color: #fff; border: 1px solid rgba(255,255,255,.28); font-size: 13px; }
.section, .page-section { padding: 58px 0; }
.section-head { max-width: 760px; margin-bottom: 26px; }
.section-head.center { margin-left: auto; margin-right: auto; text-align: center; }
.section-head h2, .section-title { font-size: clamp(28px, 4vw, 42px); line-height: 1.25; margin: 8px 0 12px; color: #17233d; }
.section-head p, .lead, .page-summary { color: var(--muted); margin: 0; font-size: 17px; }
.vpn-network-hero { position: relative; overflow: hidden; background: var(--gradient); color: #fff; padding: 58px 0 42px; }
.vpn-network-hero:before, .cta-section:before {
    content: ""; position: absolute; inset: 0; opacity: .42;
    background:
        radial-gradient(circle at 16% 22%, rgba(255,255,255,.28), transparent 22%),
        radial-gradient(circle at 82% 24%, rgba(255,255,255,.18), transparent 18%),
        linear-gradient(135deg, transparent 0 48%, rgba(255,255,255,.18) 49% 50%, transparent 51% 100%);
}
.hero-grid { position: relative; display: grid; gap: 30px; align-items: center; }
.hero-copy h1 { margin: 12px 0 16px; font-size: clamp(36px, 7vw, 64px); line-height: 1.08; letter-spacing: -.04em; }
.hero-copy p { margin: 0 0 22px; color: rgba(255,255,255,.86); font-size: 18px; }
.hero-visual { position: relative; min-height: 300px; display: grid; place-items: center; }
.hero-device { width: min(420px, 92%); border-radius: 32px; filter: drop-shadow(0 24px 38px rgba(20,30,80,.30)); }
.float-card { position: absolute; background: rgba(255,255,255,.92); color: #1f2a44; border: 1px solid rgba(255,255,255,.7); border-radius: 16px; padding: 10px 14px; box-shadow: 0 18px 38px rgba(18,32,76,.18); font-weight: 800; font-size: 13px; }
.float-card:nth-of-type(2) { top: 20px; left: 6px; }
.float-card:nth-of-type(3) { top: 42px; right: 2px; }
.float-card:nth-of-type(4) { bottom: 38px; left: 2px; }
.float-card:nth-of-type(5) { bottom: 8px; right: 20px; }
.node-overview { margin-top: -28px; position: relative; z-index: 5; }
.node-grid { display: grid; gap: 16px; }
.node-card, .feature-card, .risk-card, .faq-item, .step-card, .info-card, .side-card, .download-step, .about-card {
    background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px; box-shadow: 0 12px 28px rgba(25,45,92,.06);
}
.node-card small { color: var(--blue); font-weight: 900; letter-spacing: .12em; }
.node-card h3, .feature-card h3, .risk-card h3, .step-card h3, .info-card h3 { margin: 8px 0 8px; color: #17233d; }
.node-card p, .feature-card p, .risk-card p, .step-card p, .info-card p, .side-card p { margin: 0 0 12px; color: var(--muted); }
.split { display: grid; gap: 24px; align-items: center; }
.vpn-connection-section .image-panel, .high-speed-section .image-panel, .multi-device-section .image-panel { background: linear-gradient(180deg, #f8fbff, #eef5ff); border: 1px solid var(--line); border-radius: 32px; padding: 24px; box-shadow: var(--shadow); }
.bullet-list { display: grid; gap: 10px; padding: 0; margin: 18px 0; list-style: none; }
.bullet-list li { position: relative; padding-left: 28px; color: #43536b; }
.bullet-list li:before { content: ""; position: absolute; left: 0; top: 11px; width: 12px; height: 12px; border-radius: 50%; background: var(--blue); box-shadow: 0 0 0 5px #e8f2ff; }
.global-nodes-section { background: #f6f8fc; }
.map-panel { position: relative; overflow: hidden; min-height: 340px; border-radius: 32px; border: 1px solid var(--line); background: #fff; padding: 24px; box-shadow: var(--shadow); }
.map-panel:before { content: ""; position: absolute; inset: 24px; opacity: .18; background-image: linear-gradient(#2980FE 1px, transparent 1px), linear-gradient(90deg, #2980FE 1px, transparent 1px); background-size: 44px 44px; }
.map-panel img { position: relative; z-index: 1; margin: 24px auto 0; max-height: 300px; object-fit: contain; }
.node-points { position: relative; z-index: 2; display: grid; gap: 10px; max-width: 360px; }
.node-points span { background: #fff; border: 1px solid #d9e7ff; color: #3558f2; border-radius: 999px; padding: 8px 12px; font-weight: 800; width: max-content; }
.high-speed-section, .no-log-policy-section { background: #f8fafc; }
.speed-lines { display: grid; gap: 12px; margin-top: 18px; }
.speed-line { display: grid; gap: 8px; background: #fff; border: 1px solid var(--line); border-radius: 18px; padding: 14px; }
.speed-line strong { color: #17233d; }
.bar { height: 9px; border-radius: 999px; background: linear-gradient(90deg, #2980FE, #90c2ff); }
.privacy-protection-section .privacy-panel { display: grid; gap: 14px; background: #fff; border: 1px solid var(--line); border-radius: 32px; padding: 22px; box-shadow: var(--shadow); }
.privacy-item { border-left: 4px solid var(--blue); padding: 12px 14px; background: #f8fbff; border-radius: 14px; }
.policy-grid, .risk-grid, .faq-grid, .extension-grid, .about-grid { display: grid; gap: 16px; }
.policy-card { background: #fff; border: 1px solid var(--line); border-radius: 24px; padding: 22px; }
.policy-card span { color: var(--blue); font-weight: 900; }
.device-grid { display: grid; gap: 14px; grid-template-columns: 1fr; }
.device-card { border: 1px solid var(--line); background: #fff; border-radius: 20px; padding: 18px; }
.protocol-panel { border-radius: 32px; background: linear-gradient(135deg, #f7fbff, #ffffff); border: 1px solid var(--line); padding: 24px; box-shadow: var(--shadow); }
.protocol-stack { display: grid; gap: 12px; }
.protocol-layer { border: 1px solid #dce8ff; border-radius: 18px; padding: 14px; background: #fff; }
.process-steps { display: grid; gap: 14px; counter-reset: step; }
.step-card { position: relative; padding-left: 78px; }
.step-card:before { counter-increment: step; content: counter(step); position: absolute; left: 22px; top: 24px; width: 38px; height: 38px; border-radius: 14px; background: var(--blue); color: #fff; display: grid; place-items: center; font-weight: 900; }
.risk-card { border-left: 4px solid var(--blue); }
.risk-card strong { display: block; color: #17233d; margin: 10px 0 4px; }
.faq-item h3 { margin: 0 0 8px; color: #17233d; }
.faq-item p { margin: 0; color: var(--muted); }
.cta-section { position: relative; overflow: hidden; padding: 58px 0; background: var(--gradient); color: #fff; text-align: center; }
.cta-inner { position: relative; max-width: 720px; margin: 0 auto; }
.cta-inner h2 { font-size: clamp(28px, 4vw, 44px); line-height: 1.25; margin: 0 0 12px; }
.cta-inner p { color: rgba(255,255,255,.86); margin: 0 0 22px; }
.page-hero { background: linear-gradient(180deg, #f6f8ff, #fff); padding: 48px 0 28px; border-bottom: 1px solid var(--line); }
.page-hero h1 { font-size: clamp(32px, 5vw, 54px); line-height: 1.15; margin: 12px 0; color: #17233d; letter-spacing: -.03em; }
.content-layout { display: grid; gap: 24px; align-items: start; }
.article-panel { background: #fff; border: 1px solid var(--line); border-radius: 28px; padding: 24px; box-shadow: 0 12px 28px rgba(25,45,92,.05); }
.article-panel h2 { margin-top: 0; color: #17233d; }
.article-panel p { color: #46556b; }
.check-list { display: grid; gap: 10px; padding: 0; margin: 18px 0; list-style: none; }
.check-list li { padding: 12px 14px; border-radius: 14px; background: #f8fbff; border: 1px solid #e2eeff; color: #43536b; }
.side-column { display: grid; gap: 16px; }
.download-card { text-align: center; }
.download-card .download-btn { margin-top: 10px; }
.download-steps { display: grid; gap: 14px; }
.download-step { display: flex; gap: 14px; align-items: flex-start; }
.download-step span { flex: 0 0 38px; height: 38px; display: grid; place-items: center; border-radius: 14px; background: #eef5ff; color: var(--blue); font-weight: 900; }
.site-footer { background: #111827; color: #d1d5db; padding: 42px 0 22px; }
.footer-grid { display: grid; gap: 28px; }
.footer-brand { color: #fff; margin-bottom: 12px; }
.site-footer p { color: #aab4c2; margin: 8px 0 0; }
.site-footer h3 { color: #fff; margin: 0 0 10px; }
.site-footer a { display: block; color: #cbd5e1; margin: 7px 0; }
.site-footer a:hover { color: #fff; }
.footer-bottom { margin-top: 28px; padding-top: 18px; border-top: 1px solid rgba(255,255,255,.1); display: flex; flex-direction: column; gap: 10px; color: #9ca3af; font-size: 14px; }
@media (min-width: 680px) {
    .node-grid { grid-template-columns: repeat(2, 1fr); }
    .policy-grid, .risk-grid, .faq-grid, .extension-grid, .about-grid { grid-template-columns: repeat(2, 1fr); }
    .process-steps { grid-template-columns: repeat(2, 1fr); }
    .device-grid { grid-template-columns: repeat(3, 1fr); }
    .footer-grid { grid-template-columns: 1.4fr .8fr .8fr; }
    .footer-bottom { flex-direction: row; justify-content: space-between; align-items: center; }
}
@media (min-width: 940px) {
    .site-nav { position: static; display: flex; align-items: center; gap: 4px; background: transparent; border: 0; box-shadow: none; padding: 0; }
    .site-nav a { padding: 8px 11px; }
    .nav-toggle { display: none; }
    .vpn-network-hero { padding: 82px 0 64px; }
    .hero-grid, .split, .content-layout { grid-template-columns: 1.05fr .95fr; }
    .content-layout { grid-template-columns: minmax(0, 1fr) 330px; }
    .node-grid { grid-template-columns: repeat(4, 1fr); }
    .policy-grid { grid-template-columns: repeat(3, 1fr); }
    .risk-grid { grid-template-columns: repeat(3, 1fr); }
    .faq-grid { grid-template-columns: repeat(2, 1fr); }
    .process-steps { grid-template-columns: repeat(3, 1fr); }
    .step-card { min-height: 176px; }
    .section, .page-section { padding: 78px 0; }
    .article-panel { padding: 34px; }
}