:root {
    --primary: #2980FE;
    --primary-dark: #1768E8;
    --gradient: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    --text: #172033;
    --muted: #657086;
    --light: #F5F7FB;
    --soft: #EEF4FF;
    --border: #E5EAF3;
    --white: #FFFFFF;
    --shadow: 0 18px 45px rgba(30, 63, 130, .10);
    --radius: 24px;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", "PingFang SC", Arial, sans-serif;
    color: var(--text);
    background: #fff;
    line-height: 1.72;
    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: 50;
    background: rgba(255,255,255,.94);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border);
}
.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;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 800; color: #15213A; }
.logo { width: 38px; height: 38px; border-radius: 12px; object-fit: cover; }
.brand-text { font-size: 18px; letter-spacing: .02em; }
.nav-toggle { display: none; }
.nav-toggle-label { display: flex; width: 42px; height: 42px; align-items: center; justify-content: center; flex-direction: column; gap: 5px; border: 1px solid var(--border); border-radius: 14px; }
.nav-toggle-label span { width: 18px; height: 2px; background: #24324B; border-radius: 2px; }
.site-nav {
    display: none;
    position: absolute;
    left: 14px;
    right: 14px;
    top: 74px;
    padding: 14px;
    border: 1px solid var(--border);
    background: #fff;
    border-radius: 18px;
    box-shadow: var(--shadow);
}
.nav-toggle:checked ~ .site-nav { display: grid; gap: 8px; }
.site-nav a { padding: 10px 12px; color: #536078; border-radius: 12px; font-size: 14px; }
.site-nav a.active, .site-nav a:hover { color: var(--primary); background: #EEF5FF; }
.section { padding: 72px 0; }
.section-soft { background: var(--light); }
.eyebrow, .category-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: var(--primary);
    font-weight: 700;
    background: #EEF5FF;
    border: 1px solid #DCE9FF;
    border-radius: 999px;
    padding: 6px 12px;
    font-size: 13px;
}
.section-title { font-size: clamp(28px, 4vw, 44px); line-height: 1.18; margin: 16px 0 14px; letter-spacing: -.03em; }
.section-lead { color: var(--muted); font-size: 16px; max-width: 760px; margin: 0 0 24px; }
.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    min-width: 138px;
    padding: 13px 24px;
    border-radius: 999px;
    background: var(--primary);
    color: #fff;
    font-weight: 800;
    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: var(--primary-dark); transform: translateY(-2px); box-shadow: 0 16px 30px rgba(41,128,254,.28); }
.vpn-network-hero {
    position: relative;
    overflow: hidden;
    color: #fff;
    background: var(--gradient);
    padding: 74px 0 84px;
}
.vpn-network-hero:before, .vpn-network-hero:after {
    content: "";
    position: absolute;
    inset: auto;
    border-radius: 999px;
    background: rgba(255,255,255,.16);
    filter: blur(6px);
}
.vpn-network-hero:before { width: 360px; height: 360px; right: -80px; top: -110px; }
.vpn-network-hero:after { width: 260px; height: 260px; left: -90px; bottom: -110px; }
.hero-grid { position: relative; z-index: 1; display: grid; gap: 38px; align-items: center; }
.hero-copy h1 { font-size: clamp(34px, 8vw, 62px); line-height: 1.08; margin: 14px 0 18px; letter-spacing: -.045em; }
.hero-copy p { color: rgba(255,255,255,.88); font-size: 17px; max-width: 620px; margin: 0 0 24px; }
.hero-tags, .floating-tags, .tag-row { display: flex; flex-wrap: wrap; gap: 10px; }
.hero-tags span, .floating-tags span, .tag-row span { border: 1px solid rgba(255,255,255,.28); background: rgba(255,255,255,.14); color: #fff; padding: 8px 12px; border-radius: 999px; font-size: 13px; }
.hero-visual { position: relative; min-height: 360px; display: flex; align-items: center; justify-content: center; }
.network-card {
    position: relative;
    width: min(470px, 100%);
    padding: 18px;
    border-radius: 32px;
    background: rgba(255,255,255,.16);
    border: 1px solid rgba(255,255,255,.26);
    box-shadow: 0 30px 70px rgba(31, 43, 120, .28);
}
.network-card:before {
    content: "";
    position: absolute;
    inset: 30px;
    background-image: radial-gradient(circle, rgba(255,255,255,.9) 2px, transparent 3px), linear-gradient(120deg, rgba(255,255,255,.28) 0 1px, transparent 1px 100%);
    background-size: 76px 76px, 100% 100%;
    opacity: .42;
}
.network-card img { position: relative; z-index: 1; margin: auto; border-radius: 26px; }
.status-pill {
    position: absolute;
    z-index: 2;
    background: rgba(255,255,255,.92);
    color: #1F2A44;
    padding: 9px 12px;
    border-radius: 999px;
    font-size: 13px;
    font-weight: 700;
    box-shadow: 0 12px 28px rgba(24, 35, 90, .18);
}
.pill-one { left: 8px; top: 22px; }
.pill-two { right: 8px; top: 86px; }
.pill-three { left: 12px; bottom: 68px; }
.pill-four { right: 18px; bottom: 22px; }
.node-overview { margin-top: -44px; position: relative; z-index: 3; }
.node-grid { display: grid; gap: 16px; }
.node-card, .feature-card, .risk-card, .faq-item, .mini-card, .policy-card, .step-card {
    background: #fff;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: 0 10px 30px rgba(34, 60, 120, .06);
}
.node-card { padding: 22px; }
.node-card b { display: inline-flex; margin-bottom: 10px; color: var(--primary); background: #EEF5FF; border-radius: 999px; padding: 4px 10px; font-size: 12px; }
.node-card h3, .feature-card h3, .risk-card h3, .mini-card h3, .policy-card h3, .step-card h3 { margin: 0 0 8px; font-size: 20px; }
.node-card p, .feature-card p, .risk-card p, .mini-card p, .policy-card p, .step-card p { color: var(--muted); margin: 0 0 12px; }
.text-link { color: var(--primary); font-weight: 800; }
.split-section { display: grid; gap: 30px; align-items: center; }
.visual-panel {
    position: relative;
    padding: 20px;
    background: linear-gradient(180deg, #FFFFFF, #F6F9FF);
    border: 1px solid var(--border);
    border-radius: 32px;
    box-shadow: var(--shadow);
    overflow: hidden;
}
.visual-panel img { border-radius: 24px; margin: auto; }
.check-list { display: grid; gap: 12px; margin: 22px 0; padding: 0; list-style: none; }
.check-list li { display: flex; gap: 10px; color: #3C475B; }
.check-list li:before { content: ""; width: 8px; height: 8px; flex: 0 0 8px; margin-top: 12px; border-radius: 50%; background: var(--primary); }
.global-nodes-section {
    background: radial-gradient(circle at 20% 20%, rgba(41,128,254,.16), transparent 32%), radial-gradient(circle at 80% 30%, rgba(123,78,241,.14), transparent 28%), #F6F8FC;
}
.map-panel { position: relative; padding: 28px; border-radius: 32px; background: #fff; border: 1px solid var(--border); box-shadow: var(--shadow); overflow: hidden; }
.map-panel:before {
    content: "";
    position: absolute;
    inset: 0;
    background-image: radial-gradient(circle, rgba(41,128,254,.26) 2px, transparent 3px), linear-gradient(90deg, transparent 0 18px, rgba(41,128,254,.07) 18px 19px, transparent 19px 38px), linear-gradient(0deg, transparent 0 18px, rgba(41,128,254,.06) 18px 19px, transparent 19px 38px);
    background-size: 72px 72px, 38px 38px, 38px 38px;
    opacity: .75;
}
.map-panel > * { position: relative; z-index: 1; }
.speed-lines { display: grid; gap: 12px; margin-top: 22px; }
.speed-line { padding: 14px; border-radius: 18px; background: #fff; border: 1px solid var(--border); display: flex; justify-content: space-between; gap: 12px; color: #44516A; }
.speed-line span:last-child { color: var(--primary); font-weight: 800; }
.privacy-panel { padding: 24px; border-radius: 30px; background: #fff; border: 1px solid var(--border); box-shadow: var(--shadow); }
.privacy-tags { display: grid; gap: 12px; margin-top: 20px; }
.privacy-tags span { padding: 14px; border-radius: 16px; background: #F3F7FF; color: #32405E; font-weight: 700; }
.policy-grid, .risk-grid, .faq-grid, .feature-grid, .steps-grid { display: grid; gap: 16px; }
.policy-card, .risk-card, .feature-card, .mini-card, .step-card { padding: 22px; }
.tech-panel { background: #fff; border: 1px solid var(--border); border-radius: 32px; box-shadow: var(--shadow); padding: 24px; }
.protocol-stack { display: grid; gap: 12px; margin-top: 18px; }
.protocol-stack div { padding: 14px 16px; background: #F4F7FC; border-radius: 16px; border-left: 4px solid var(--primary); }
.process-steps { background: linear-gradient(180deg, #fff, #F7FAFF); }
.step-number { width: 34px; height: 34px; border-radius: 50%; background: var(--primary); color: #fff; display: inline-flex; align-items: center; justify-content: center; font-weight: 800; margin-bottom: 12px; }
.risk-card { border-left: 4px solid var(--primary); }
.faq-item { padding: 20px; }
.faq-item h3 { margin: 0 0 8px; font-size: 18px; }
.faq-item p { margin: 0; color: var(--muted); }
.cta-section { color: #fff; background: var(--gradient); text-align: center; border-radius: 34px; padding: 46px 22px; position: relative; overflow: hidden; }
.cta-section p { color: rgba(255,255,255,.86); max-width: 680px; margin: 0 auto 24px; }
.page-hero { padding: 54px 0 36px; background: linear-gradient(180deg, #F4F8FF 0%, #FFFFFF 100%); }
.page-hero h1 { margin: 16px 0 14px; font-size: clamp(32px, 6vw, 52px); line-height: 1.15; letter-spacing: -.035em; }
.page-hero p { color: var(--muted); max-width: 790px; margin: 0; font-size: 17px; }
.content-layout { display: grid; gap: 24px; align-items: start; }
.article-card { background: #fff; border: 1px solid var(--border); border-radius: 28px; padding: 24px; box-shadow: var(--shadow); }
.article-card h2 { margin-top: 0; font-size: 26px; }
.article-card p { color: #48546A; }
.side-panel { background: #F7FAFF; border: 1px solid var(--border); border-radius: 26px; padding: 22px; position: sticky; top: 90px; }
.side-panel h3 { margin-top: 0; }
.side-panel a { display: block; padding: 10px 0; color: var(--primary); font-weight: 700; }
.info-list { display: grid; gap: 12px; padding: 0; margin: 18px 0 0; list-style: none; }
.info-list li { padding: 14px; background: #F6F8FC; border-radius: 16px; border: 1px solid var(--border); }
.download-panel { margin-top: 24px; padding: 24px; border-radius: 26px; background: #F4F8FF; border: 1px solid #DCE9FF; text-align: center; }
.download-steps { counter-reset: item; display: grid; gap: 14px; margin: 24px 0; }
.download-steps div { padding: 18px; border-radius: 18px; background: #fff; border: 1px solid var(--border); }
.faq-list { display: grid; gap: 14px; }
.site-footer { background: #172033; color: #DCE4F5; padding: 54px 0 0; }
.footer-grid { display: grid; gap: 24px; }
.footer-brand { display: flex; align-items: center; gap: 10px; font-size: 20px; font-weight: 800; color: #fff; margin-bottom: 10px; }
.footer-brand img { width: 38px; height: 38px; border-radius: 12px; object-fit: cover; }
.site-footer h3 { color: #fff; margin: 0 0 10px; }
.site-footer p { color: #AEBBD0; margin: 0; }
.site-footer a { display: block; color: #AEBBD0; padding: 5px 0; }
.site-footer a:hover { color: #fff; }
.footer-bottom { margin-top: 34px; padding: 18px 16px; text-align: center; border-top: 1px solid rgba(255,255,255,.10); color: #AEBBD0; font-size: 14px; }
@media (min-width: 700px) {
    .node-grid { grid-template-columns: repeat(2, 1fr); }
    .feature-grid, .policy-grid, .risk-grid, .faq-grid, .steps-grid { grid-template-columns: repeat(2, 1fr); }
    .footer-grid { grid-template-columns: 1.4fr 1fr 1fr 1fr; }
}
@media (min-width: 980px) {
    .nav-toggle-label { display: none; }
    .site-nav { position: static; display: flex; align-items: center; gap: 4px; padding: 0; border: 0; background: transparent; box-shadow: none; }
    .hero-grid, .split-section { grid-template-columns: 1.04fr .96fr; }
    .split-section.reverse { grid-template-columns: .96fr 1.04fr; }
    .node-grid { grid-template-columns: repeat(4, 1fr); }
    .policy-grid { grid-template-columns: repeat(3, 1fr); }
    .risk-grid { grid-template-columns: repeat(4, 1fr); }
    .steps-grid { grid-template-columns: repeat(3, 1fr); }
    .content-layout { grid-template-columns: minmax(0, 1fr) 310px; }
    .section { padding: 92px 0; }
    .page-hero { padding: 70px 0 48px; }
}
@media (max-width: 480px) {
    .container { width: min(100% - 24px, 1120px); }
    .vpn-network-hero { padding: 54px 0 66px; }
    .hero-visual { min-height: 300px; }
    .status-pill { position: static; display: inline-flex; margin: 6px; }
    .network-card { padding-bottom: 60px; }
    .section { padding: 56px 0; }
    .article-card, .side-panel, .policy-card, .risk-card, .feature-card, .node-card, .step-card { padding: 18px; }
}