:root {
    --gradient: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    --blue: #2980FE;
    --blue-dark: #1768E8;
    --text: #1f2937;
    --muted: #5f6b7a;
    --light: #f6f8fc;
    --line: #e5eaf2;
    --white: #ffffff;
    --radius: 24px;
    --shadow: 0 18px 50px rgba(38, 76, 160, 0.12);
}
* { 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: #ffffff;
    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; }
.section { padding: 64px 0; }
.section-soft { background: var(--light); }
.eyebrow, .badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: var(--blue);
    background: rgba(41,128,254,.10);
    border: 1px solid rgba(41,128,254,.18);
    border-radius: 999px;
    padding: 6px 12px;
    font-size: 14px;
    font-weight: 700;
}
.section-title { font-size: clamp(28px, 4vw, 44px); line-height: 1.18; margin: 14px 0 14px; letter-spacing: -0.02em; }
.section-lead { color: var(--muted); margin: 0 0 24px; font-size: 16px; }
.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 0 24px;
    border-radius: 999px;
    background: #2980FE;
    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;
    white-space: nowrap;
}
.download-btn:hover { background: #1768E8; transform: translateY(-2px); box-shadow: 0 18px 34px rgba(23,104,232,.30); }
.link-more { color: var(--blue); font-weight: 700; }
.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 {
    width: min(1180px, calc(100% - 28px));
    min-height: 70px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 900; color: #172033; }
.brand-logo { width: 38px; height: 38px; border-radius: 12px; object-fit: cover; }
.site-nav {
    position: absolute;
    left: 14px;
    right: 14px;
    top: 72px;
    display: none;
    flex-direction: column;
    gap: 6px;
    padding: 14px;
    border: 1px solid var(--line);
    border-radius: 20px;
    background: #fff;
    box-shadow: var(--shadow);
}
.site-nav.open { display: flex; }
.site-nav a {
    padding: 10px 12px;
    border-radius: 12px;
    color: #405064;
    font-weight: 700;
    font-size: 14px;
}
.site-nav a.active, .site-nav a:hover { background: rgba(41,128,254,.10); color: var(--blue); }
.nav-toggle { display: inline-flex; flex-direction: column; gap: 5px; border: 0; background: transparent; padding: 8px; cursor: pointer; }
.nav-toggle span { width: 24px; height: 2px; background: #172033; border-radius: 2px; }
.vpn-network-hero {
    position: relative;
    overflow: hidden;
    background: var(--gradient);
    color: #fff;
    padding: 70px 0 56px;
}
.vpn-network-hero::before,
.vpn-network-hero::after {
    content: "";
    position: absolute;
    border-radius: 999px;
    background: rgba(255,255,255,.18);
    filter: blur(8px);
}
.vpn-network-hero::before { width: 360px; height: 360px; right: -120px; top: -120px; }
.vpn-network-hero::after { width: 280px; height: 280px; left: -80px; bottom: -120px; }
.hero-grid { position: relative; z-index: 1; display: grid; gap: 32px; align-items: center; }
.hero-copy h1 { font-size: clamp(36px, 8vw, 68px); line-height: 1.06; margin: 14px 0 18px; letter-spacing: -0.04em; }
.hero-copy p { color: rgba(255,255,255,.86); font-size: 17px; margin: 0 0 24px; }
.hero-tags, .float-tags, .mini-tags { display: flex; flex-wrap: wrap; gap: 10px; }
.hero-tags span, .float-tags span, .mini-tags span {
    border: 1px solid rgba(255,255,255,.28);
    background: rgba(255,255,255,.12);
    color: #fff;
    border-radius: 999px;
    padding: 7px 11px;
    font-size: 13px;
    font-weight: 700;
}
.hero-actions { display: flex; flex-wrap: wrap; gap: 14px; align-items: center; margin-bottom: 18px; }
.hero-note { color: rgba(255,255,255,.76); font-size: 14px; }
.hero-visual { position: relative; min-height: 320px; }
.hero-panel {
    position: relative;
    z-index: 1;
    padding: 22px;
    border: 1px solid rgba(255,255,255,.24);
    border-radius: 32px;
    background: rgba(255,255,255,.16);
    box-shadow: 0 26px 80px rgba(23,35,92,.24);
}
.hero-panel img { margin: 0 auto; max-height: 390px; object-fit: contain; }
.network-lines {
    position: absolute;
    inset: 12px;
    border-radius: 36px;
    background:
      radial-gradient(circle at 18% 28%, rgba(255,255,255,.95) 0 3px, transparent 4px),
      radial-gradient(circle at 78% 22%, rgba(255,255,255,.82) 0 3px, transparent 4px),
      radial-gradient(circle at 45% 72%, rgba(255,255,255,.74) 0 3px, transparent 4px),
      linear-gradient(135deg, transparent 24%, rgba(255,255,255,.20) 25%, transparent 26%),
      linear-gradient(25deg, transparent 35%, rgba(255,255,255,.18) 36%, transparent 37%);
    opacity: .8;
}
.status-chip {
    position: absolute;
    z-index: 2;
    color: #172033;
    background: #fff;
    border-radius: 999px;
    padding: 8px 12px;
    box-shadow: 0 14px 35px rgba(0,0,0,.16);
    font-size: 13px;
    font-weight: 800;
}
.chip-a { left: 8px; top: 28px; }
.chip-b { right: 0; top: 88px; }
.chip-c { left: 20px; bottom: 52px; }
.chip-d { right: 22px; bottom: 16px; }
.node-overview {
    margin-top: -36px;
    position: relative;
    z-index: 3;
}
.node-overview-grid { display: grid; gap: 16px; }
.node-card, .card, .risk-card, .faq-item, .service-card, .step-card {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 22px;
    padding: 22px;
    box-shadow: 0 12px 32px rgba(28,52,98,.07);
}
.node-card small { color: var(--blue); font-weight: 900; letter-spacing: .06em; }
.node-card h3, .card h3, .risk-card h3, .service-card h3, .step-card h3 { margin: 8px 0 8px; font-size: 20px; }
.node-card p, .card p, .risk-card p, .service-card p, .step-card p { color: var(--muted); margin: 0 0 12px; }
.split-section { display: grid; gap: 28px; align-items: center; }
.image-card {
    border-radius: 32px;
    background: linear-gradient(145deg, #ffffff, #f0f5ff);
    border: 1px solid var(--line);
    padding: 22px;
    box-shadow: var(--shadow);
}
.image-card img { margin: 0 auto; max-height: 360px; object-fit: contain; }
.bullet-list { padding: 0; margin: 18px 0 0; list-style: none; display: grid; gap: 10px; }
.bullet-list li { position: relative; padding-left: 24px; color: #38465a; }
.bullet-list li::before { content: ""; position: absolute; left: 0; top: 12px; width: 9px; height: 9px; border-radius: 50%; background: var(--blue); }
.global-nodes-section { background: linear-gradient(180deg, #f7f9ff 0%, #ffffff 100%); }
.map-panel {
    position: relative;
    overflow: hidden;
    border-radius: 32px;
    padding: 24px;
    background:
      radial-gradient(circle at 20% 20%, rgba(41,128,254,.16), transparent 28%),
      radial-gradient(circle at 76% 30%, rgba(123,78,241,.16), transparent 30%),
      #fff;
    border: 1px solid var(--line);
    box-shadow: var(--shadow);
}
.map-panel::before {
    content: "";
    position: absolute;
    inset: 20px;
    border-radius: 28px;
    background-image: linear-gradient(90deg, rgba(41,128,254,.08) 1px, transparent 1px), linear-gradient(rgba(41,128,254,.08) 1px, transparent 1px);
    background-size: 42px 42px;
}
.map-panel > * { position: relative; z-index: 1; }
.node-list { display: grid; gap: 12px; margin-top: 18px; }
.node-line { display: flex; justify-content: space-between; gap: 16px; background: rgba(255,255,255,.82); border: 1px solid var(--line); padding: 12px 14px; border-radius: 16px; }
.high-speed-section { background: #f4f7fb; }
.speed-cards { display: grid; gap: 14px; margin-top: 20px; }
.speed-card { background: #fff; border: 1px solid var(--line); border-left: 4px solid var(--blue); border-radius: 18px; padding: 16px; }
.privacy-protection-section .privacy-panel, .tech-panel, .policy-panel {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 28px;
    padding: 24px;
    box-shadow: var(--shadow);
}
.privacy-grid, .policy-grid, .device-grid, .protocol-grid, .risk-grid, .faq-grid, .content-grid, .related-grid { display: grid; gap: 16px; }
.policy-card, .device-card, .protocol-card {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 20px;
    padding: 20px;
}
.process-steps { display: grid; gap: 16px; counter-reset: step; }
.step-card { position: relative; padding-top: 54px; }
.step-card::before {
    counter-increment: step;
    content: counter(step, decimal-leading-zero);
    position: absolute;
    top: 18px;
    left: 20px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 42px;
    height: 28px;
    border-radius: 999px;
    color: #fff;
    background: var(--blue);
    font-weight: 900;
}
.risk-card { border-left: 4px solid var(--blue); }
.cta-section {
    padding: 66px 0;
    background: var(--gradient);
    color: #fff;
    text-align: center;
}
.cta-box { width: min(820px, calc(100% - 32px)); margin: 0 auto; }
.cta-box p { color: rgba(255,255,255,.84); margin: 0 auto 24px; max-width: 680px; }
.page-hero { padding: 54px 0 34px; background: linear-gradient(180deg, #f7f9ff 0%, #fff 100%); }
.page-hero h1 { font-size: clamp(32px, 6vw, 54px); line-height: 1.12; margin: 14px 0; letter-spacing: -0.03em; }
.page-hero p { color: var(--muted); max-width: 760px; margin: 0; }
.article-layout { display: grid; gap: 24px; align-items: start; }
.article-main { display: grid; gap: 18px; }
.article-main p { margin: 0; color: #435166; }
.side-panel { background: #fff; border: 1px solid var(--line); border-radius: 24px; padding: 22px; box-shadow: 0 12px 32px rgba(28,52,98,.07); }
.check-list { margin: 0; padding: 0; list-style: none; display: grid; gap: 12px; }
.check-list li { padding: 12px 14px; background: #f7f9ff; border: 1px solid var(--line); border-radius: 14px; color: #405064; }
.info-box { border-radius: 22px; padding: 20px; background: #f5f8ff; border: 1px solid #dce7ff; color: #405064; }
.download-panel { margin-top: 18px; padding: 24px; border: 1px solid var(--line); border-radius: 24px; background: #fff; text-align: center; box-shadow: var(--shadow); }
.faq-item h3 { margin: 0 0 8px; font-size: 18px; }
.faq-item p { margin: 0; color: var(--muted); }
.download-steps { counter-reset: dstep; display: grid; gap: 14px; padding: 0; margin: 22px 0; list-style: none; }
.download-steps li { position: relative; padding: 16px 16px 16px 58px; border: 1px solid var(--line); border-radius: 18px; background: #fff; }
.download-steps li::before { counter-increment: dstep; content: counter(dstep); position: absolute; left: 16px; top: 16px; width: 30px; height: 30px; border-radius: 50%; background: var(--blue); color: #fff; display: grid; place-items: center; font-weight: 900; }
.site-footer { background: #111827; color: rgba(255,255,255,.76); padding-top: 48px; }
.footer-grid { display: grid; gap: 28px; }
.footer-brand { display: flex; align-items: center; gap: 10px; color: #fff; font-weight: 900; margin-bottom: 12px; }
.footer-brand img { width: 38px; height: 38px; border-radius: 12px; object-fit: cover; }
.site-footer h3 { color: #fff; margin: 0 0 12px; }
.site-footer a { display: block; color: rgba(255,255,255,.72); margin: 7px 0; }
.site-footer a:hover { color: #fff; }
.footer-bottom { margin-top: 34px; border-top: 1px solid rgba(255,255,255,.10); padding: 18px 16px; text-align: center; font-size: 14px; color: rgba(255,255,255,.58); }
@media (min-width: 700px) {
    .node-overview-grid, .policy-grid, .device-grid, .protocol-grid, .risk-grid, .faq-grid, .related-grid { grid-template-columns: repeat(2, 1fr); }
    .process-steps { grid-template-columns: repeat(2, 1fr); }
    .footer-grid { grid-template-columns: 1.4fr repeat(3, 1fr); }
}
@media (min-width: 960px) {
    .section { padding: 86px 0; }
    .nav-toggle { display: none; }
    .site-nav { position: static; display: flex; flex-direction: row; align-items: center; width: auto; padding: 0; border: 0; border-radius: 0; box-shadow: none; background: transparent; }
    .site-nav a { padding: 8px 10px; }
    .hero-grid, .split-section { grid-template-columns: 1.04fr .96fr; gap: 54px; }
    .node-overview-grid { grid-template-columns: repeat(4, 1fr); }
    .privacy-grid, .content-grid, .article-layout { grid-template-columns: 1.4fr .8fr; }
    .policy-grid, .device-grid, .protocol-grid, .risk-grid { grid-template-columns: repeat(3, 1fr); }
    .faq-grid { grid-template-columns: repeat(2, 1fr); }
    .process-steps { grid-template-columns: repeat(3, 1fr); }
    .reverse .image-card { order: -1; }
}
@media (max-width: 480px) {
    .container { width: min(100% - 24px, 1120px); }
    .vpn-network-hero { padding-top: 46px; }
    .hero-copy h1 { font-size: 34px; }
    .status-chip { position: static; display: inline-flex; margin: 6px 5px 0 0; }
    .hero-visual { min-height: auto; }
    .hero-panel { padding: 16px; }
    .download-btn { width: 100%; }
    .section { padding: 50px 0; }
    .card, .node-card, .risk-card, .service-card, .step-card { padding: 18px; }
}