:root {
    --gradient: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    --blue: #2980FE;
    --blue-dark: #1768E8;
    --text: #1f2937;
    --muted: #64748b;
    --light: #f6f8fb;
    --line: #e5eaf2;
    --panel: #ffffff;
    --soft-blue: #eef5ff;
    --shadow: 0 18px 45px rgba(20, 35, 80, .10);
    --radius: 24px;
}
* { 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: 1.7;
    overflow-x: hidden;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
main { min-height: 60vh; }
.site-header {
    position: sticky;
    top: 0;
    z-index: 50;
    background: rgba(255,255,255,.94);
    backdrop-filter: blur(18px);
    border-bottom: 1px solid rgba(226,232,240,.8);
}
.header-inner,
.footer-inner,
.container,
.content-container {
    width: min(1160px, calc(100% - 32px));
    margin: 0 auto;
}
.header-inner {
    min-height: 72px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
}
.brand { display: inline-flex; align-items: center; gap: 10px; font-weight: 800; color: #172554; white-space: nowrap; }
.logo-img { width: 42px; height: 42px; border-radius: 12px; object-fit: cover; }
.brand-text { letter-spacing: .02em; }
.nav-toggle { display: none; }
.nav-trigger { display: flex; width: 42px; height: 42px; border: 1px solid var(--line); border-radius: 14px; align-items: center; justify-content: center; flex-direction: column; gap: 5px; cursor: pointer; }
.nav-trigger span { width: 18px; height: 2px; border-radius: 2px; background: #1e293b; }
.site-nav {
    position: absolute;
    top: 72px;
    left: 16px;
    right: 16px;
    display: none;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 20px;
    padding: 12px;
    box-shadow: var(--shadow);
}
.site-nav a { display: block; padding: 12px 14px; border-radius: 12px; color: #475569; font-size: 15px; }
.site-nav a.active, .site-nav a:hover { background: var(--soft-blue); color: var(--blue); }
.nav-toggle:checked ~ .site-nav { display: block; }
.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 13px 24px;
    border-radius: 999px;
    background: #2980FE;
    color: #fff;
    font-weight: 700;
    box-shadow: 0 12px 24px rgba(41,128,254,.24);
    transition: transform .2s ease, background .2s ease, box-shadow .2s ease;
}
.download-btn:hover { background: #1768E8; transform: translateY(-2px); box-shadow: 0 16px 30px rgba(23,104,232,.28); }
.text-link { color: var(--blue); font-weight: 700; }
.text-link:hover { color: var(--blue-dark); }
.section { padding: 72px 0; }
.section-soft { background: var(--light); }
.section-title { margin: 0 0 14px; font-size: clamp(28px, 5vw, 44px); line-height: 1.18; color: #0f172a; }
.section-lead { margin: 0; color: var(--muted); font-size: 17px; max-width: 760px; }
.badge, .category-badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 12px;
    border-radius: 999px;
    background: #eaf3ff;
    color: var(--blue);
    font-size: 13px;
    font-weight: 800;
}
.vpn-network-hero {
    position: relative;
    overflow: hidden;
    background: var(--gradient);
    color: #fff;
    padding: 72px 0 52px;
}
.vpn-network-hero::before,
.vpn-network-hero::after {
    content: "";
    position: absolute;
    inset: auto;
    border-radius: 999px;
    background: rgba(255,255,255,.16);
    filter: blur(8px);
}
.vpn-network-hero::before { width: 380px; height: 380px; right: -120px; top: -100px; }
.vpn-network-hero::after { width: 260px; height: 260px; left: -90px; bottom: -80px; }
.hero-grid { position: relative; z-index: 1; display: grid; gap: 36px; align-items: center; }
.hero-content h1 { margin: 18px 0 18px; font-size: clamp(36px, 9vw, 68px); line-height: 1.05; letter-spacing: -.04em; }
.hero-content p { margin: 0 0 24px; color: rgba(255,255,255,.88); font-size: 18px; max-width: 660px; }
.hero-tags { display: flex; flex-wrap: wrap; gap: 10px; margin: 24px 0 0; }
.hero-tags span { border: 1px solid rgba(255,255,255,.28); background: rgba(255,255,255,.13); padding: 8px 12px; border-radius: 999px; font-size: 13px; }
.hero-visual { position: relative; min-height: 320px; display: grid; place-items: center; }
.hero-visual::before {
    content: "";
    position: absolute;
    inset: 8% 5%;
    background-image: radial-gradient(circle, rgba(255,255,255,.7) 1.4px, transparent 1.5px), linear-gradient(120deg, transparent 0 45%, rgba(255,255,255,.25) 45% 46%, transparent 46% 100%);
    background-size: 38px 38px, 100% 100%;
    opacity: .46;
}
.hero-device { position: relative; z-index: 1; width: min(430px, 88%); border-radius: 30px; box-shadow: 0 28px 70px rgba(10, 20, 60, .25); }
.float-card { position: absolute; z-index: 2; padding: 10px 13px; border-radius: 16px; background: rgba(255,255,255,.94); color: #172554; box-shadow: 0 14px 36px rgba(15,23,42,.18); font-size: 13px; font-weight: 800; }
.float-one { top: 8%; left: 4%; }
.float-two { top: 22%; right: 0; }
.float-three { bottom: 18%; left: 0; }
.float-four { bottom: 7%; right: 8%; }
.node-overview { margin-top: -28px; position: relative; z-index: 3; }
.node-overview-grid { display: grid; grid-template-columns: 1fr; gap: 16px; }
.node-card, .feature-card, .risk-card, .faq-item, .step-card, .policy-card, .info-card, .article-card {
    background: var(--panel);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    box-shadow: 0 14px 36px rgba(30,41,59,.06);
}
.node-card { padding: 24px; }
.node-card .tag { display: inline-flex; padding: 4px 10px; border-radius: 999px; background: var(--soft-blue); color: var(--blue); font-size: 12px; font-weight: 800; margin-bottom: 10px; }
.node-card h3, .feature-card h3, .risk-card h3, .policy-card h3, .info-card h3 { margin: 0 0 10px; color: #0f172a; }
.node-card p, .feature-card p, .risk-card p, .policy-card p, .info-card p { margin: 0 0 14px; color: var(--muted); }
.split-section { display: grid; gap: 28px; align-items: center; }
.image-panel { position: relative; border-radius: 32px; overflow: hidden; background: #fff; border: 1px solid var(--line); box-shadow: var(--shadow); padding: 14px; }
.image-panel img { border-radius: 24px; width: 100%; }
.feature-list { display: grid; gap: 12px; margin: 22px 0; padding: 0; list-style: none; }
.feature-list li { position: relative; padding: 14px 14px 14px 42px; border-radius: 16px; background: #f8fbff; color: #334155; border: 1px solid #e7eef8; }
.feature-list li::before { content: ""; position: absolute; left: 16px; top: 20px; width: 10px; height: 10px; border-radius: 50%; background: var(--blue); box-shadow: 0 0 0 5px rgba(41,128,254,.12); }
.vpn-connection-section { background: #fff; }
.global-nodes-section { background: linear-gradient(180deg, #f8fbff 0%, #ffffff 100%); }
.node-map-panel {
    position: relative;
    overflow: hidden;
    border-radius: 32px;
    padding: 26px;
    border: 1px solid #dbe7f7;
    background: radial-gradient(circle at 20% 20%, rgba(41,128,254,.16), transparent 32%), radial-gradient(circle at 80% 35%, rgba(123,78,241,.12), transparent 30%), #fff;
    box-shadow: var(--shadow);
}
.node-map-panel::before { content: ""; position: absolute; inset: 0; background-image: radial-gradient(circle, rgba(41,128,254,.45) 1.4px, transparent 1.5px); background-size: 42px 42px; opacity: .35; }
.node-map-panel > * { position: relative; z-index: 1; }
.node-points { display: grid; gap: 12px; margin-top: 18px; }
.node-point { display: flex; justify-content: space-between; gap: 14px; padding: 12px 14px; border-radius: 16px; background: rgba(255,255,255,.86); border: 1px solid rgba(219,231,247,.9); color: #334155; }
.high-speed-section { background: #f3f7fc; }
.speed-lines { display: grid; gap: 14px; margin-top: 20px; }
.speed-line { padding: 16px; border-radius: 18px; background: #fff; border: 1px solid var(--line); }
.speed-line strong { display: block; color: #0f172a; margin-bottom: 6px; }
.privacy-protection-section { background: #fff; }
.safety-panel { padding: 26px; border-radius: 30px; background: #f8fbff; border: 1px solid #dfeafb; }
.safety-tags { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 16px; }
.safety-tags span { padding: 8px 12px; border-radius: 999px; background: #fff; border: 1px solid var(--line); color: #334155; }
.no-log-policy-section { background: #f7f9fc; }
.policy-grid, .card-grid { display: grid; gap: 18px; margin-top: 28px; }
.policy-card, .feature-card, .info-card { padding: 24px; }
.multi-device-section { background: #fff; }
.device-grid { display: grid; gap: 14px; margin-top: 20px; }
.device-card { padding: 18px; border-radius: 20px; background: #f8fbff; border: 1px solid var(--line); }
.device-card strong { display: block; color: #172554; }
.encryption-protocol-section { background: linear-gradient(180deg, #ffffff 0%, #f5f8fe 100%); }
.tech-panel { padding: 26px; border-radius: 30px; background: #0f2b5c; color: #fff; box-shadow: var(--shadow); }
.tech-panel p { color: rgba(255,255,255,.82); }
.protocol-row { display: grid; gap: 12px; margin-top: 18px; }
.protocol-row div { padding: 14px; border-radius: 16px; background: rgba(255,255,255,.1); border: 1px solid rgba(255,255,255,.16); }
.process-steps { display: grid; gap: 16px; margin-top: 28px; }
.step-card { padding: 22px; position: relative; }
.step-number { display: inline-grid; place-items: center; width: 38px; height: 38px; border-radius: 14px; background: var(--blue); color: #fff; font-weight: 800; margin-bottom: 12px; }
.risk-grid { display: grid; gap: 16px; margin-top: 28px; }
.risk-card { padding: 22px; border-left: 4px solid var(--blue); }
.risk-card .suggest { display: block; margin-top: 10px; color: #0f172a; font-weight: 700; }
.faq-list { display: grid; gap: 14px; margin-top: 28px; }
.faq-item { padding: 22px; }
.faq-item h3 { margin: 0 0 8px; color: #0f172a; }
.faq-item p { margin: 0; color: var(--muted); }
.cta-section { padding: 72px 0; background: var(--gradient); color: #fff; text-align: center; }
.cta-section .container { max-width: 820px; }
.cta-section h2 { margin: 0 0 12px; font-size: clamp(28px, 5vw, 44px); line-height: 1.2; }
.cta-section p { margin: 0 auto 24px; color: rgba(255,255,255,.88); max-width: 680px; }
.page-hero { padding: 64px 0 44px; background: linear-gradient(180deg, #f4f8ff 0%, #fff 100%); }
.page-hero h1 { margin: 14px 0 14px; font-size: clamp(32px, 7vw, 54px); line-height: 1.12; color: #0f172a; }
.page-hero p { margin: 0; max-width: 780px; color: var(--muted); font-size: 18px; }
.article-layout { display: grid; gap: 24px; align-items: start; }
.article-main, .article-aside { display: grid; gap: 18px; }
.article-card { padding: 24px; }
.article-card h2 { margin: 0 0 10px; color: #0f172a; }
.article-card p { margin: 0 0 12px; color: #475569; }
.check-list, .number-list { margin: 0; padding-left: 20px; color: #475569; }
.check-list li, .number-list li { margin: 8px 0; }
.side-box { padding: 22px; border-radius: 22px; background: #f8fbff; border: 1px solid var(--line); }
.side-box h3 { margin: 0 0 10px; }
.side-box p, .side-box li { color: var(--muted); }
.download-panel { margin-top: 12px; padding: 26px; border-radius: 28px; background: #fff; border: 1px solid var(--line); box-shadow: var(--shadow); }
.download-steps { counter-reset: steps; display: grid; gap: 14px; margin-top: 24px; }
.download-step { padding: 18px; border-radius: 18px; background: #f8fbff; border: 1px solid var(--line); }
.download-step strong { color: #0f172a; }
.site-footer { background: #111827; color: #e5e7eb; padding-top: 54px; }
.footer-inner { display: grid; gap: 28px; }
.footer-brand p { color: #b6c2d2; max-width: 420px; }
.footer-logo { color: #fff; }
.footer-links { display: grid; gap: 20px; }
.footer-links h3 { margin: 0 0 10px; color: #fff; }
.footer-links a { display: block; color: #b6c2d2; padding: 5px 0; }
.footer-links a:hover { color: #fff; }
.footer-bottom { margin-top: 34px; border-top: 1px solid rgba(255,255,255,.1); padding: 18px 16px; text-align: center; color: #aab6c8; font-size: 14px; }
@media (min-width: 700px) {
    .node-overview-grid { grid-template-columns: repeat(2, 1fr); }
    .policy-grid, .card-grid { grid-template-columns: repeat(2, 1fr); }
    .risk-grid { grid-template-columns: repeat(2, 1fr); }
    .process-steps { grid-template-columns: repeat(2, 1fr); }
    .footer-links { grid-template-columns: repeat(3, 1fr); }
}
@media (min-width: 980px) {
    .nav-trigger { display: none; }
    .site-nav { position: static; display: flex; align-items: center; gap: 2px; background: transparent; border: 0; border-radius: 0; padding: 0; box-shadow: none; }
    .site-nav a { display: inline-flex; padding: 9px 11px; font-size: 14px; }
    .hero-grid { grid-template-columns: 1.04fr .96fr; }
    .node-overview-grid { grid-template-columns: repeat(4, 1fr); }
    .split-section { grid-template-columns: 1fr 1fr; }
    .split-section.reverse .image-panel { order: -1; }
    .policy-grid { grid-template-columns: repeat(3, 1fr); }
    .card-grid { grid-template-columns: repeat(3, 1fr); }
    .process-steps { grid-template-columns: repeat(3, 1fr); }
    .risk-grid { grid-template-columns: repeat(4, 1fr); }
    .article-layout { grid-template-columns: minmax(0, 1fr) 320px; }
    .footer-inner { grid-template-columns: 1fr 1.4fr; }
}
@media (max-width: 430px) {
    .header-inner, .footer-inner, .container, .content-container { width: min(100% - 22px, 1160px); }
    .section { padding: 54px 0; }
    .vpn-network-hero { padding: 54px 0 42px; }
    .float-card { position: static; margin: 8px 4px; display: inline-flex; }
    .hero-visual { display: block; text-align: center; min-height: auto; }
    .hero-device { margin: 18px auto 6px; }
    .download-btn { width: 100%; }
}