:root {
  --gradient: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
  --blue: #2980FE;
  --blue-hover: #1768E8;
  --text: #20293A;
  --muted: #687386;
  --line: #E5EAF3;
  --soft: #F6F8FC;
  --soft-blue: #F1F6FF;
  --white: #FFFFFF;
  --radius-lg: 30px;
  --radius-md: 22px;
  --shadow: 0 18px 46px rgba(21, 34, 77, .10);
}

* { 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: #FBFCFF;
  line-height: 1.75;
  font-size: 16px;
}
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-header { max-width: 760px; margin: 0 auto 28px; text-align: center; }
.section-header h2, .section-title { margin: 0 0 12px; font-size: clamp(28px, 4vw, 42px); line-height: 1.18; letter-spacing: -.03em; }
.section-header p, .lead { margin: 0; color: var(--muted); }
.badge, .category-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--blue);
  background: #EAF3FF;
  border: 1px solid #D8E8FF;
  border-radius: 999px;
  padding: 7px 13px;
  font-weight: 700;
  font-size: 13px;
}
.download-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 13px 24px;
  border-radius: 999px;
  background: var(--blue);
  color: #fff;
  font-weight: 800;
  box-shadow: 0 10px 24px rgba(41, 128, 254, .26);
  transition: transform .2s ease, background .2s ease, box-shadow .2s ease;
  border: 0;
}
.download-btn:hover { background: var(--blue-hover); transform: translateY(-2px); box-shadow: 0 14px 28px rgba(23, 104, 232, .32); }
.text-link { color: var(--blue); font-weight: 800; }
.text-link:hover { color: var(--blue-hover); }

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(255, 255, 255, .94);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid rgba(229, 234, 243, .9);
}
.header-inner { display: flex; align-items: center; justify-content: space-between; min-height: 72px; gap: 18px; }
.logo { display: inline-flex; align-items: center; gap: 10px; font-weight: 900; letter-spacing: -.02em; color: var(--text); }
.logo img { width: 42px; height: 42px; border-radius: 12px; object-fit: cover; box-shadow: 0 8px 18px rgba(53, 88, 242, .16); }
.nav-toggle { border: 1px solid var(--line); background: #fff; color: var(--text); border-radius: 12px; width: 44px; height: 40px; font-size: 21px; }
.site-nav { display: none; position: absolute; left: 16px; right: 16px; top: 72px; padding: 12px; border: 1px solid var(--line); border-radius: 18px; background: #fff; box-shadow: var(--shadow); }
.site-nav.open { display: grid; gap: 6px; }
.site-nav a { padding: 10px 12px; border-radius: 12px; color: var(--muted); font-weight: 700; }
.site-nav a:hover, .site-nav a.active { color: var(--blue); background: #F0F6FF; }

.vpn-network-hero {
  position: relative;
  overflow: hidden;
  color: #fff;
  background: var(--gradient);
  padding: 68px 0 54px;
}
.vpn-network-hero::before,
.vpn-network-hero::after {
  content: "";
  position: absolute;
  inset: auto;
  border-radius: 50%;
  background: rgba(255, 255, 255, .18);
  filter: blur(6px);
}
.vpn-network-hero::before { width: 380px; height: 380px; right: -130px; top: -120px; }
.vpn-network-hero::after { width: 240px; height: 240px; left: -90px; bottom: -80px; }
.hero-grid { position: relative; display: grid; gap: 34px; align-items: center; }
.hero-copy h1 { font-size: clamp(36px, 8vw, 64px); line-height: 1.05; letter-spacing: -.05em; margin: 16px 0; }
.hero-copy p { margin: 0 0 22px; color: rgba(255,255,255,.9); font-size: 18px; }
.hero-tags { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 20px; }
.hero-tags span, .status-card, .network-pill { background: rgba(255,255,255,.16); border: 1px solid rgba(255,255,255,.28); color: #fff; border-radius: 999px; padding: 8px 12px; font-weight: 700; font-size: 13px; }
.hero-visual { position: relative; min-height: 310px; display: grid; place-items: center; }
.node-lines {
  position: absolute;
  inset: 0;
  border-radius: 32px;
  opacity: .8;
  background:
    radial-gradient(circle at 20% 25%, rgba(255,255,255,.9) 0 3px, transparent 4px),
    radial-gradient(circle at 78% 18%, rgba(255,255,255,.75) 0 3px, transparent 4px),
    radial-gradient(circle at 65% 72%, rgba(255,255,255,.75) 0 3px, transparent 4px),
    linear-gradient(35deg, transparent 10%, rgba(255,255,255,.22) 10% 12%, transparent 13% 100%),
    linear-gradient(150deg, transparent 15%, rgba(255,255,255,.20) 15% 17%, transparent 18% 100%);
}
.hero-device { position: relative; width: min(420px, 92%); padding: 18px; border-radius: 34px; background: rgba(255,255,255,.18); border: 1px solid rgba(255,255,255,.25); box-shadow: 0 24px 80px rgba(24, 22, 78, .26); }
.hero-device img { border-radius: 24px; width: 100%; background: #fff; }
.status-card { position: absolute; backdrop-filter: blur(12px); box-shadow: 0 14px 34px rgba(0,0,0,.16); }
.status-card.one { left: 6px; top: 24px; }
.status-card.two { right: 0; top: 82px; }
.status-card.three { left: 18px; bottom: 36px; }
.status-card.four { right: 18px; bottom: 12px; }

.node-overview { margin-top: -28px; position: relative; z-index: 4; }
.node-overview-grid { display: grid; gap: 16px; }
.node-card, .feature-card, .risk-card, .faq-item, .step-card, .policy-card, .mini-card, .info-card {
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  box-shadow: 0 12px 34px rgba(30, 46, 95, .06);
}
.node-card { padding: 22px; }
.node-card .label { display: inline-block; color: var(--blue); background: #EAF3FF; border-radius: 999px; padding: 3px 10px; font-size: 12px; font-weight: 800; }
.node-card h3, .feature-card h3, .risk-card h3, .mini-card h3, .info-card h3 { margin: 12px 0 8px; font-size: 20px; }
.node-card p, .feature-card p, .risk-card p, .mini-card p, .info-card p { color: var(--muted); margin: 0 0 14px; }

.split-section { display: grid; gap: 28px; align-items: center; }
.feature-card { padding: 26px; }
.feature-list { display: grid; gap: 12px; margin: 20px 0; padding: 0; list-style: none; }
.feature-list li { position: relative; padding-left: 26px; color: var(--muted); }
.feature-list li::before { content: ""; position: absolute; left: 0; top: .62em; width: 10px; height: 10px; border-radius: 50%; background: var(--blue); box-shadow: 0 0 0 5px #EAF3FF; }
.visual-panel { position: relative; overflow: hidden; border-radius: var(--radius-lg); background: #fff; border: 1px solid var(--line); box-shadow: var(--shadow); padding: 18px; }
.visual-panel img { border-radius: 22px; width: 100%; }
.panel-tag { position: absolute; left: 24px; bottom: 24px; background: #fff; color: var(--text); border-radius: 999px; padding: 9px 14px; box-shadow: 0 10px 28px rgba(20, 31, 66, .15); font-weight: 800; }

.vpn-connection-section { background: #fff; }
.global-nodes-section { background: var(--soft-blue); }
.high-speed-section { background: var(--soft); }
.privacy-protection-section { background: #fff; }
.no-log-policy-section { background: var(--soft-blue); }
.multi-device-section { background: #fff; }
.encryption-protocol-section { background: var(--soft); }
.map-panel {
  overflow: hidden;
  border-radius: var(--radius-lg);
  background:
    radial-gradient(circle at 20% 30%, rgba(41,128,254,.18), transparent 18%),
    radial-gradient(circle at 82% 24%, rgba(123,78,241,.16), transparent 20%),
    radial-gradient(circle at 62% 80%, rgba(184,77,218,.14), transparent 18%),
    #fff;
  border: 1px solid var(--line);
  padding: 20px;
  box-shadow: var(--shadow);
}
.map-panel img { border-radius: 24px; margin-bottom: 16px; }
.network-pills { display: flex; flex-wrap: wrap; gap: 10px; }
.network-pill { background: #F0F6FF; color: var(--blue); border-color: #D8E8FF; }
.speed-grid, .policy-grid, .risk-grid, .faq-grid, .article-grid, .mini-grid { display: grid; gap: 16px; }
.speed-line { padding: 18px; border-radius: 18px; background: #fff; border: 1px solid var(--line); }
.speed-line b { display: block; margin-bottom: 8px; }
.speed-bar { height: 9px; border-radius: 999px; background: #E8EEF8; overflow: hidden; }
.speed-bar span { display: block; height: 100%; border-radius: inherit; background: var(--blue); }
.privacy-panel { padding: 28px; border-radius: var(--radius-lg); background: #fff; border: 1px solid var(--line); box-shadow: var(--shadow); }
.privacy-tags { display: flex; flex-wrap: wrap; gap: 10px; margin: 18px 0; }
.privacy-tags span { background: #F0F6FF; color: var(--blue); border-radius: 999px; padding: 8px 12px; font-weight: 800; font-size: 13px; }
.policy-card { padding: 22px; }
.protocol-panel { padding: 24px; border-radius: var(--radius-lg); border: 1px solid var(--line); background: #fff; box-shadow: var(--shadow); }
.protocol-stack { display: grid; gap: 12px; margin-top: 20px; }
.protocol-layer { padding: 16px; border-radius: 16px; border: 1px solid var(--line); background: #F9FBFF; }

.process-steps { display: grid; gap: 14px; counter-reset: step; }
.step-card { padding: 20px; position: relative; }
.step-num { width: 36px; height: 36px; display: inline-grid; place-items: center; border-radius: 12px; background: var(--blue); color: #fff; font-weight: 900; margin-bottom: 10px; }
.risk-card { padding: 20px; border-left: 4px solid var(--blue); }
.risk-card .suggest { margin-top: 10px; padding: 10px 12px; border-radius: 14px; background: #F3F7FF; color: var(--text); }
.faq-item { padding: 20px; }
.faq-item h3 { margin: 0 0 8px; font-size: 18px; }
.faq-item p { margin: 0; color: var(--muted); }
.cta-section { padding: 66px 0; color: #fff; background: var(--gradient); text-align: center; position: relative; overflow: hidden; }
.cta-section::before { content: ""; position: absolute; width: 420px; height: 420px; border-radius: 50%; background: rgba(255,255,255,.14); right: -160px; top: -180px; }
.cta-section .container { position: relative; }
.cta-section h2 { margin: 0 0 12px; font-size: clamp(28px, 5vw, 44px); }
.cta-section p { color: rgba(255,255,255,.88); margin: 0 auto 22px; max-width: 680px; }

.page-hero { padding: 58px 0 34px; background: linear-gradient(180deg, #F1F6FF, #FBFCFF); }
.page-hero h1 { margin: 14px 0 12px; font-size: clamp(32px, 6vw, 52px); line-height: 1.12; letter-spacing: -.04em; }
.page-hero p { max-width: 760px; color: var(--muted); margin: 0; font-size: 18px; }
.content-section { padding: 44px 0 68px; }
.article-grid { grid-template-columns: 1fr; align-items: start; }
.article-main { background: #fff; border: 1px solid var(--line); border-radius: var(--radius-lg); padding: 24px; box-shadow: 0 12px 34px rgba(30,46,95,.05); }
.article-main h2 { margin-top: 0; font-size: 26px; }
.article-main p { color: var(--muted); }
.article-main ul, .article-main ol { padding-left: 20px; color: var(--muted); }
.article-main li { margin: 8px 0; }
.sidebar { display: grid; gap: 16px; }
.info-card { padding: 20px; }
.check-list { list-style: none; padding: 0; margin: 12px 0 0; display: grid; gap: 10px; }
.check-list li { padding: 12px 14px; border-radius: 14px; background: #F6F8FC; color: var(--muted); }
.download-box { margin-top: 22px; padding: 20px; border-radius: 22px; background: #F3F7FF; border: 1px solid #DCEAFF; }
.download-box p { margin: 0 0 14px; color: var(--muted); }

.download-page-grid { display: grid; gap: 22px; align-items: start; }
.download-panel { background: #fff; border: 1px solid var(--line); border-radius: var(--radius-lg); padding: 26px; box-shadow: var(--shadow); }
.install-steps { display: grid; gap: 14px; margin-top: 18px; }
.install-step { display: flex; gap: 12px; padding: 16px; border-radius: 18px; border: 1px solid var(--line); background: #fff; }
.install-step b { width: 32px; height: 32px; flex: 0 0 32px; display: grid; place-items: center; background: var(--blue); color: #fff; border-radius: 11px; }

.site-footer { background: #182131; color: #D8DEE9; padding-top: 46px; }
.footer-grid { display: grid; gap: 24px; }
.footer-brand { color: #fff; font-size: 20px; font-weight: 900; margin-bottom: 10px; }
.site-footer h3 { color: #fff; margin: 0 0 12px; font-size: 16px; }
.site-footer a { display: block; color: #C5CEDD; margin: 8px 0; }
.site-footer a:hover { color: #fff; }
.site-footer p { color: #AEB8C8; margin: 0; }
.footer-note { margin-top: 12px !important; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,.09); margin-top: 32px; padding: 18px 16px; text-align: center; color: #AEB8C8; }

@media (min-width: 680px) {
  .node-overview-grid { grid-template-columns: repeat(2, 1fr); }
  .mini-grid, .policy-grid, .risk-grid, .faq-grid { grid-template-columns: repeat(2, 1fr); }
  .download-page-grid { grid-template-columns: 1.1fr .9fr; }
}

@media (min-width: 920px) {
  .nav-toggle { display: none; }
  .site-nav { position: static; display: flex; align-items: center; gap: 2px; padding: 0; border: 0; border-radius: 0; background: transparent; box-shadow: none; }
  .site-nav a { font-size: 14px; }
  .vpn-network-hero { padding: 92px 0 84px; }
  .hero-grid { grid-template-columns: 1.02fr .98fr; gap: 48px; }
  .node-overview-grid { grid-template-columns: repeat(4, 1fr); }
  .split-section { grid-template-columns: 1fr 1fr; gap: 48px; }
  .split-section.reverse .visual-panel, .split-section.reverse .map-panel { order: -1; }
  .speed-grid { grid-template-columns: .9fr 1.1fr; align-items: center; }
  .policy-grid { grid-template-columns: repeat(3, 1fr); }
  .process-steps { grid-template-columns: repeat(3, 1fr); }
  .risk-grid { grid-template-columns: repeat(4, 1fr); }
  .faq-grid { grid-template-columns: repeat(2, 1fr); }
  .article-grid { grid-template-columns: minmax(0, 1fr) 320px; gap: 24px; }
  .article-main { padding: 34px; }
  .footer-grid { grid-template-columns: 1.3fr .8fr .8fr .9fr; }
}

@media (max-width: 420px) {
  .container { width: min(100% - 24px, 1120px); }
  .hero-copy p, .page-hero p { font-size: 16px; }
  .status-card { position: static; display: inline-flex; margin: 6px; }
  .hero-visual { display: block; min-height: auto; }
  .hero-device { margin: 0 auto 12px; }
  .section { padding: 48px 0; }
  .article-main { padding: 20px; border-radius: 22px; }
  .download-btn { width: 100%; }
}