:root {
    --gradient: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    --blue: #2980FE;
    --blue-dark: #1768E8;
    --text: #20283A;
    --muted: #667085;
    --light: #F5F7FB;
    --line: #E6EAF2;
    --white: #FFFFFF;
    --radius-lg: 28px;
    --radius-md: 20px;
    --shadow: 0 18px 50px rgba(32, 40, 58, 0.08);
}
* { 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%; display: block; }
.container {
    width: min(1120px, calc(100% - 36px));
    margin: 0 auto;
}
.site-header {
    position: sticky;
    top: 0;
    z-index: 50;
    background: rgba(255,255,255,0.94);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid rgba(230,234,242,0.9);
}
.header-inner {
    width: min(1180px, calc(100% - 28px));
    margin: 0 auto;
    min-height: 68px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
}
.logo {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-weight: 800;
    font-size: 20px;
    color: #1F2A44;
    white-space: nowrap;
}
.logo img { width: 38px; height: 38px; border-radius: 12px; object-fit: cover; }
.nav-toggle {
    border: 1px solid var(--line);
    background: #fff;
    color: var(--text);
    width: 42px;
    height: 42px;
    border-radius: 14px;
    font-size: 22px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
}
.site-nav {
    position: absolute;
    left: 14px;
    right: 14px;
    top: 72px;
    display: none;
    flex-direction: column;
    gap: 6px;
    padding: 14px;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 22px;
    box-shadow: var(--shadow);
}
.site-nav.open { display: flex; }
.site-nav a {
    padding: 10px 12px;
    border-radius: 12px;
    color: #344054;
    font-size: 15px;
}
.site-nav a.active,
.site-nav a:hover { color: var(--blue); background: #EEF5FF; }
.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: 700;
    box-shadow: 0 12px 28px rgba(41, 128, 254, 0.24);
    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 34px rgba(23,104,232,0.28); }
.vpn-network-hero {
    position: relative;
    color: #fff;
    background: var(--gradient);
    overflow: hidden;
}
.vpn-network-hero:before,
.vpn-network-hero:after {
    content: "";
    position: absolute;
    width: 420px;
    height: 420px;
    border-radius: 50%;
    background: rgba(255,255,255,0.14);
    filter: blur(10px);
}
.vpn-network-hero:before { top: -200px; right: -120px; }
.vpn-network-hero:after { bottom: -260px; left: -160px; }
.hero-grid {
    position: relative;
    z-index: 1;
    min-height: 660px;
    display: grid;
    gap: 36px;
    align-items: center;
    padding: 58px 0 70px;
}
.hero-copy h1 {
    margin: 0 0 18px;
    font-size: clamp(36px, 9vw, 64px);
    line-height: 1.12;
    letter-spacing: -1.5px;
}
.hero-copy p { margin: 0 0 26px; max-width: 680px; color: rgba(255,255,255,0.86); font-size: 17px; }
.hero-tags, .visual-badges, .tag-row { display: flex; flex-wrap: wrap; gap: 10px; }
.hero-tags span, .visual-badges span, .tag, .badge {
    display: inline-flex;
    align-items: center;
    border-radius: 999px;
    padding: 7px 12px;
    font-size: 13px;
    font-weight: 700;
}
.hero-tags span { background: rgba(255,255,255,0.14); border: 1px solid rgba(255,255,255,0.22); }
.hero-visual {
    position: relative;
    min-height: 360px;
    display: flex;
    align-items: center;
    justify-content: center;
}
.network-lines {
    position: absolute;
    inset: 0;
    background:
        radial-gradient(circle at 18% 28%, rgba(255,255,255,.8) 0 3px, transparent 4px),
        radial-gradient(circle at 78% 18%, rgba(255,255,255,.55) 0 3px, transparent 4px),
        radial-gradient(circle at 72% 76%, rgba(255,255,255,.7) 0 3px, transparent 4px),
        linear-gradient(30deg, transparent 0 20%, rgba(255,255,255,.22) 20% 21%, transparent 21% 100%),
        linear-gradient(145deg, transparent 0 32%, rgba(255,255,255,.18) 32% 33%, transparent 33% 100%);
    opacity: .95;
}
.hero-device {
    position: relative;
    width: min(440px, 92%);
    padding: 18px;
    border-radius: 34px;
    background: rgba(255,255,255,0.18);
    border: 1px solid rgba(255,255,255,0.28);
    box-shadow: 0 32px 80px rgba(16,24,40,.22);
}
.hero-device img { border-radius: 26px; background: rgba(255,255,255,.08); }
.status-card {
    position: absolute;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 14px;
    border-radius: 16px;
    background: rgba(255,255,255,0.92);
    color: #26324D;
    font-size: 13px;
    font-weight: 800;
    box-shadow: 0 14px 34px rgba(16,24,40,.15);
}
.status-card:before { content: ""; width: 8px; height: 8px; border-radius: 50%; background: var(--blue); }
.status-a { top: 16px; left: 4px; }
.status-b { top: 78px; right: 2px; }
.status-c { bottom: 72px; left: 6px; }
.status-d { bottom: 16px; right: 8px; }
.section { padding: 70px 0; }
.section-soft { background: var(--light); }
.section-title { margin: 0 0 14px; font-size: clamp(28px, 5vw, 42px); line-height: 1.22; letter-spacing: -0.6px; }
.section-lead { margin: 0 0 32px; color: var(--muted); max-width: 760px; }
.node-overview { margin-top: -42px; position: relative; z-index: 3; }
.node-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-md);
    padding: 22px;
    box-shadow: 0 12px 34px rgba(16,24,40,.05);
}
.node-card .label, .feature-card .label, .page-badge {
    display: inline-flex;
    color: var(--blue);
    background: #EEF5FF;
    border-radius: 999px;
    padding: 5px 10px;
    font-size: 12px;
    font-weight: 800;
    margin-bottom: 10px;
}
.node-card h3, .feature-card h3, .risk-card h3, .step-card h3, .info-card h3 { margin: 0 0 10px; font-size: 20px; }
.node-card p, .feature-card p, .risk-card p, .step-card p, .info-card p { margin: 0 0 12px; color: var(--muted); }
.text-link { color: var(--blue); font-weight: 800; }
.split-section, .vpn-connection-section, .global-nodes-section, .high-speed-section, .privacy-protection-section, .multi-device-section, .encryption-protocol-section {
    display: grid;
    gap: 28px;
    align-items: center;
}
.visual-panel {
    position: relative;
    border-radius: var(--radius-lg);
    overflow: hidden;
    border: 1px solid var(--line);
    background: #fff;
    box-shadow: var(--shadow);
    padding: 18px;
}
.visual-panel img { border-radius: 22px; margin: 0 auto; }
.feature-list { display: grid; gap: 12px; margin: 22px 0; padding: 0; list-style: none; }
.feature-list li {
    position: relative;
    padding-left: 28px;
    color: #3D475C;
}
.feature-list li:before {
    content: "";
    position: absolute;
    left: 0;
    top: 12px;
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--blue);
    box-shadow: 0 0 0 5px #EEF5FF;
}
.global-nodes-section {
    background:
      radial-gradient(circle at 14% 22%, rgba(41,128,254,.13), transparent 32%),
      radial-gradient(circle at 78% 72%, rgba(123,78,241,.12), transparent 30%),
      #fff;
    border: 1px solid var(--line);
    border-radius: var(--radius-lg);
    padding: 22px;
    box-shadow: var(--shadow);
}
.node-map {
    position: relative;
    min-height: 260px;
    border-radius: 24px;
    background: #F8FAFF;
    overflow: hidden;
}
.node-map:before {
    content: "";
    position: absolute;
    inset: 0;
    background:
      radial-gradient(circle at 25% 28%, var(--blue) 0 4px, transparent 5px),
      radial-gradient(circle at 64% 40%, #7B4EF1 0 4px, transparent 5px),
      radial-gradient(circle at 48% 74%, #B84DDA 0 4px, transparent 5px),
      linear-gradient(35deg, transparent 0 29%, rgba(41,128,254,.18) 29% 30%, transparent 31%),
      linear-gradient(145deg, transparent 0 36%, rgba(123,78,241,.16) 36% 37%, transparent 38%);
}
.node-map img { position: relative; z-index: 1; width: 86%; margin: 34px auto; }
.speed-lines { display: grid; gap: 14px; margin-top: 18px; }
.speed-line {
    padding: 14px;
    border: 1px solid var(--line);
    background: #fff;
    border-radius: 18px;
}
.speed-line strong { display: flex; justify-content: space-between; gap: 12px; color: #1F2A44; }
.speed-bar { height: 8px; border-radius: 999px; background: #E9F1FF; margin-top: 12px; overflow: hidden; }
.speed-bar span { display: block; height: 100%; border-radius: inherit; background: var(--blue); }
.safety-panel {
    border-radius: var(--radius-lg);
    background: #fff;
    border: 1px solid var(--line);
    box-shadow: var(--shadow);
    padding: 24px;
}
.safety-panel .panel-row {
    display: flex;
    gap: 12px;
    padding: 14px 0;
    border-bottom: 1px solid var(--line);
}
.safety-panel .panel-row:last-child { border-bottom: 0; }
.safety-panel .dot { width: 12px; height: 12px; border-radius: 50%; background: var(--blue); margin-top: 8px; flex: 0 0 auto; }
.policy-grid, .risk-grid, .faq-grid, .device-grid, .protocol-grid { display: grid; gap: 16px; }
.no-log-policy-section .policy-grid { margin-top: 22px; }
.device-card {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 22px;
    padding: 18px;
}
.device-card strong { display: block; margin-bottom: 6px; }
.protocol-panel {
    border-radius: var(--radius-lg);
    background: #fff;
    border: 1px solid var(--line);
    padding: 24px;
    box-shadow: var(--shadow);
}
.protocol-row {
    display: grid;
    grid-template-columns: 92px 1fr;
    gap: 16px;
    align-items: start;
    padding: 16px 0;
    border-bottom: 1px solid var(--line);
}
.protocol-row:last-child { border-bottom: 0; }
.protocol-row span { color: var(--blue); font-weight: 900; }
.process-steps {
    display: grid;
    gap: 16px;
    counter-reset: step;
}
.step-card { position: relative; }
.step-number {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: 14px;
    background: #EEF5FF;
    color: var(--blue);
    font-weight: 900;
    margin-bottom: 12px;
}
.risk-card { border-left: 4px solid var(--blue); }
.risk-card small { display: block; color: var(--muted); margin-top: 8px; }
.faq-item h3 { font-size: 18px; }
.faq-item p { color: var(--muted); margin-bottom: 0; }
.cta-section {
    padding: 74px 0;
    background: var(--gradient);
    color: #fff;
    text-align: center;
    position: relative;
    overflow: hidden;
}
.cta-section:before {
    content: "";
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at 25% 10%, rgba(255,255,255,.22), transparent 32%), radial-gradient(circle at 80% 90%, rgba(255,255,255,.14), transparent 35%);
}
.cta-section .container { position: relative; z-index: 1; }
.cta-section h2 { margin: 0 0 14px; font-size: clamp(28px, 6vw, 44px); }
.cta-section p { margin: 0 auto 24px; max-width: 720px; color: rgba(255,255,255,.84); }
.page-hero {
    padding: 56px 0 34px;
    background: linear-gradient(180deg, #F5F8FF 0%, #FFFFFF 100%);
}
.page-hero h1 { margin: 0 0 14px; font-size: clamp(30px, 7vw, 52px); line-height: 1.18; letter-spacing: -0.8px; }
.page-hero p { margin: 0; color: var(--muted); max-width: 760px; }
.content-layout {
    display: grid;
    gap: 24px;
    padding: 34px 0 70px;
}
.article-card {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: var(--radius-lg);
    padding: 24px;
    box-shadow: var(--shadow);
}
.article-card h2 { margin: 0 0 12px; font-size: 26px; }
.article-card p { color: #4C5870; }
.notice-box, .checklist, .side-panel {
    background: #F8FAFF;
    border: 1px solid var(--line);
    border-radius: 22px;
    padding: 20px;
    margin-top: 20px;
}
.checklist ul, .notice-box ul { margin: 10px 0 0; padding-left: 20px; color: #4C5870; }
.side-panel { background: #fff; margin-top: 0; position: sticky; top: 88px; height: fit-content; }
.side-panel h3 { margin: 0 0 12px; }
.side-panel a { display: block; padding: 10px 0; border-bottom: 1px solid var(--line); color: var(--blue); font-weight: 800; }
.side-panel a:last-child { border-bottom: 0; }
.page-cta { margin-top: 24px; }
.download-steps { display: grid; gap: 14px; margin-top: 24px; }
.download-step {
    display: grid;
    grid-template-columns: 44px 1fr;
    gap: 14px;
    align-items: start;
    padding: 18px;
    border: 1px solid var(--line);
    border-radius: 20px;
    background: #fff;
}
.download-step b {
    display: inline-flex;
    width: 44px;
    height: 44px;
    align-items: center;
    justify-content: center;
    border-radius: 14px;
    background: #EEF5FF;
    color: var(--blue);
}
.site-footer { background: #111827; color: #D1D5DB; padding-top: 54px; }
.footer-grid { display: grid; gap: 28px; }
.footer-brand { display: inline-flex; align-items: center; gap: 10px; color: #fff; font-size: 20px; margin-bottom: 12px; }
.footer-brand img { width: 36px; height: 36px; border-radius: 12px; object-fit: cover; }
.site-footer h3 { color: #fff; margin: 0 0 12px; font-size: 18px; }
.site-footer a { display: block; color: #D1D5DB; padding: 4px 0; }
.site-footer a:hover { color: #fff; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,.1); margin-top: 34px; padding: 18px; text-align: center; color: #9CA3AF; }
@media (min-width: 680px) {
    .node-overview-grid, .policy-grid, .risk-grid, .faq-grid, .device-grid, .protocol-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .process-steps { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .footer-grid { grid-template-columns: 1.4fr .8fr .8fr; }
}
@media (min-width: 980px) {
    .nav-toggle { display: none; }
    .site-nav { position: static; display: flex; flex-direction: row; align-items: center; gap: 2px; padding: 0; border: 0; box-shadow: none; background: transparent; }
    .site-nav a { font-size: 14px; }
    .hero-grid { grid-template-columns: 1.06fr .94fr; padding: 76px 0 96px; }
    .node-overview-grid { grid-template-columns: repeat(4, minmax(0, 1fr)); }
    .vpn-connection-section, .global-nodes-section, .high-speed-section, .privacy-protection-section, .multi-device-section, .encryption-protocol-section, .split-section { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .risk-grid { grid-template-columns: repeat(4, minmax(0, 1fr)); }
    .policy-grid, .device-grid, .protocol-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
    .faq-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .process-steps { grid-template-columns: repeat(3, minmax(0, 1fr)); }
    .content-layout { grid-template-columns: minmax(0, 1fr) 320px; align-items: start; }
    .article-card { padding: 34px; }
}
@media (max-width: 420px) {
    .container { width: min(100% - 28px, 1120px); }
    .download-btn { width: 100%; }
    .hero-tags span, .visual-badges span { font-size: 12px; }
    .status-card { position: static; margin: 8px; }
    .visual-badges { position: relative; z-index: 2; justify-content: center; margin-top: 10px; }
    .protocol-row { grid-template-columns: 1fr; gap: 4px; }
}