:root {
    --gradient: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    --blue: #2980FE;
    --blue-hover: #1768E8;
    --text: #182033;
    --muted: #5f6b82;
    --light: #f5f7fb;
    --line: #e5eaf3;
    --card: #ffffff;
    --radius-lg: 30px;
    --radius-md: 22px;
    --shadow: 0 20px 50px rgba(41, 128, 254, 0.12);
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "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% - 32px)); margin: 0 auto; }
.site-header {
    position: sticky;
    top: 0;
    z-index: 20;
    background: rgba(255,255,255,0.94);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--line);
}
.header-inner {
    width: min(1180px, calc(100% - 32px));
    margin: 0 auto;
    min-height: 70px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
}
.brand { display: inline-flex; align-items: center; gap: 10px; font-weight: 800; color: #16213d; }
.logo-img { width: 42px; height: 42px; object-fit: contain; border-radius: 12px; }
.brand-text { font-size: 19px; letter-spacing: .02em; }
.nav-toggle {
    display: inline-flex;
    border: 1px solid var(--line);
    background: #fff;
    border-radius: 999px;
    padding: 9px 14px;
    color: var(--text);
    font-weight: 700;
}
.site-nav {
    position: absolute;
    left: 16px;
    right: 16px;
    top: 74px;
    display: none;
    flex-direction: column;
    gap: 6px;
    padding: 14px;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 18px;
    box-shadow: var(--shadow);
}
.site-nav.open { display: flex; }
.site-nav a {
    padding: 10px 12px;
    border-radius: 12px;
    color: #36435c;
    font-weight: 650;
    font-size: 14px;
}
.site-nav a:hover, .site-nav a.active { background: #eef5ff; color: var(--blue); }
.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 12px 24px;
    border-radius: 999px;
    background: var(--blue);
    color: #fff;
    font-weight: 800;
    box-shadow: 0 14px 28px rgba(41, 128, 254, .28);
    transition: transform .2s ease, background .2s ease, box-shadow .2s ease;
}
.download-btn:hover { background: var(--blue-hover); transform: translateY(-2px); box-shadow: 0 18px 32px rgba(23, 104, 232, .3); }
.section { padding: 64px 0; }
.section-soft { background: var(--light); }
.section-title { font-size: clamp(28px, 4vw, 44px); line-height: 1.18; margin: 0 0 16px; letter-spacing: -0.03em; }
.section-lead { color: var(--muted); margin: 0 0 24px; max-width: 760px; }
.eyebrow, .badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 6px 12px;
    border-radius: 999px;
    background: #eef5ff;
    color: var(--blue);
    font-weight: 800;
    font-size: 13px;
    margin-bottom: 14px;
}
.link-arrow { color: var(--blue); font-weight: 800; }
.vpn-network-hero {
    position: relative;
    overflow: hidden;
    background: var(--gradient);
    color: #fff;
    padding: 70px 0 54px;
}
.vpn-network-hero:before {
    content: "";
    position: absolute;
    inset: 0;
    background:
        radial-gradient(circle at 18% 22%, rgba(255,255,255,.28), transparent 24%),
        radial-gradient(circle at 84% 18%, rgba(255,255,255,.18), transparent 20%),
        linear-gradient(135deg, rgba(255,255,255,.18) 1px, transparent 1px);
    background-size: auto, auto, 42px 42px;
    opacity: .68;
}
.hero-grid { position: relative; z-index: 1; display: grid; gap: 34px; align-items: center; }
.hero-content h1 { font-size: clamp(38px, 8vw, 68px); line-height: 1.08; margin: 0 0 18px; letter-spacing: -0.05em; }
.hero-content p { color: rgba(255,255,255,.88); font-size: 17px; margin: 0 0 24px; max-width: 650px; }
.hero-tags, .status-tags { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 24px; }
.hero-tags span, .status-tags span {
    padding: 8px 12px;
    border-radius: 999px;
    background: rgba(255,255,255,.16);
    border: 1px solid rgba(255,255,255,.28);
    color: #fff;
    font-weight: 700;
    font-size: 13px;
}
.hero-visual { position: relative; min-height: 320px; display: grid; place-items: center; }
.hero-device {
    width: min(440px, 90%);
    padding: 20px;
    background: rgba(255,255,255,.16);
    border: 1px solid rgba(255,255,255,.25);
    border-radius: 34px;
    box-shadow: 0 30px 80px rgba(15, 22, 55, .25);
}
.float-card {
    position: absolute;
    background: rgba(255,255,255,.92);
    color: #1f2a44;
    border-radius: 18px;
    padding: 10px 14px;
    font-weight: 800;
    box-shadow: 0 18px 35px rgba(22, 34, 66, .18);
    border: 1px solid rgba(255,255,255,.5);
    font-size: 13px;
}
.float-card.one { top: 14px; left: 0; }
.float-card.two { top: 42px; right: 0; }
.float-card.three { bottom: 54px; left: 6px; }
.float-card.four { bottom: 18px; right: 16px; }
.node-overview { margin-top: -34px; position: relative; z-index: 3; }
.node-overview-grid { display: grid; gap: 16px; }
.node-card, .feature-card, .risk-card, .faq-item, .step-card, .policy-card, .info-card {
    background: var(--card);
    border: 1px solid var(--line);
    border-radius: var(--radius-md);
    padding: 22px;
    box-shadow: 0 14px 36px rgba(29, 50, 90, .06);
}
.node-card .label { color: var(--blue); font-weight: 900; font-size: 13px; }
.node-card h3, .feature-card h3, .risk-card h3, .step-card h3, .policy-card h3 { margin: 8px 0 8px; font-size: 20px; }
.node-card p, .feature-card p, .risk-card p, .step-card p, .policy-card p, .info-card p { color: var(--muted); margin: 0 0 12px; }
.split { display: grid; gap: 30px; align-items: center; }
.visual-panel {
    position: relative;
    padding: 22px;
    border-radius: var(--radius-lg);
    background: linear-gradient(180deg, #fff, #f7faff);
    border: 1px solid var(--line);
    box-shadow: var(--shadow);
}
.feature-list { display: grid; gap: 12px; margin: 20px 0; padding: 0; list-style: none; }
.feature-list li {
    padding: 12px 14px;
    border-left: 4px solid var(--blue);
    background: #f7faff;
    border-radius: 14px;
    color: #33405a;
}
.global-nodes-section {
    position: relative;
    overflow: hidden;
    background: #f6f8fc;
}
.global-map-panel {
    border-radius: var(--radius-lg);
    padding: 24px;
    min-height: 340px;
    background:
        radial-gradient(circle at 22% 30%, rgba(41,128,254,.18), transparent 15%),
        radial-gradient(circle at 72% 36%, rgba(123,78,241,.18), transparent 17%),
        radial-gradient(circle at 52% 78%, rgba(184,77,218,.14), transparent 14%),
        #ffffff;
    border: 1px solid var(--line);
    box-shadow: var(--shadow);
}
.node-line { height: 1px; background: linear-gradient(90deg, transparent, rgba(41,128,254,.42), transparent); margin: 16px 0; }
.speed-grid, .privacy-grid, .policy-grid, .device-grid, .protocol-grid, .risk-grid, .faq-grid { display: grid; gap: 18px; }
.speed-meter {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 24px;
    padding: 18px;
}
.meter-row { display: flex; justify-content: space-between; color: var(--muted); font-weight: 700; margin-bottom: 8px; }
.meter-bar { height: 10px; border-radius: 999px; background: #e8effc; overflow: hidden; }
.meter-bar span { display: block; height: 100%; width: 72%; background: var(--blue); border-radius: inherit; }
.privacy-panel {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: var(--radius-lg);
    padding: 24px;
    box-shadow: var(--shadow);
}
.security-tags { display: flex; flex-wrap: wrap; gap: 10px; margin: 18px 0; }
.security-tags span { border: 1px solid #d8e6ff; background: #f1f6ff; color: var(--blue); border-radius: 999px; padding: 8px 12px; font-weight: 800; font-size: 13px; }
.process-steps { display: grid; gap: 16px; counter-reset: step; }
.step-card { position: relative; padding-left: 72px; }
.step-card:before {
    counter-increment: step;
    content: counter(step);
    position: absolute;
    left: 20px;
    top: 24px;
    width: 36px;
    height: 36px;
    display: grid;
    place-items: center;
    border-radius: 50%;
    background: var(--blue);
    color: #fff;
    font-weight: 900;
}
.risk-card { border-left: 4px solid var(--blue); }
.faq-item h3 { margin: 0 0 8px; font-size: 18px; }
.faq-item p { color: var(--muted); margin: 0; }
.cta-section {
    background: var(--gradient);
    color: #fff;
    text-align: center;
    padding: 62px 0;
    position: relative;
    overflow: hidden;
}
.cta-section:before { content: ""; position: absolute; inset: 0; background: radial-gradient(circle at 50% 10%, rgba(255,255,255,.28), transparent 28%); }
.cta-section .container { position: relative; z-index: 1; }
.cta-section p { color: rgba(255,255,255,.86); max-width: 680px; margin: 0 auto 24px; }
.page-hero {
    background: linear-gradient(180deg, #f4f7ff, #fff);
    padding: 60px 0 34px;
    border-bottom: 1px solid var(--line);
}
.page-hero h1 { font-size: clamp(32px, 6vw, 52px); line-height: 1.15; margin: 0 0 14px; letter-spacing: -0.04em; }
.page-hero p { color: var(--muted); max-width: 780px; margin: 0; }
.article-layout { display: grid; gap: 24px; padding: 44px 0 64px; }
.article-main { display: grid; gap: 20px; }
.article-main p { color: var(--muted); margin: 0; }
.article-card, .side-card {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: var(--radius-md);
    padding: 24px;
    box-shadow: 0 12px 32px rgba(29,50,90,.06);
}
.article-card h2, .side-card h2 { margin: 0 0 12px; font-size: 24px; }
.check-list { display: grid; gap: 10px; padding: 0; list-style: none; margin: 16px 0 0; }
.check-list li { padding: 12px 14px; background: #f7faff; border: 1px solid #e8eef8; border-radius: 14px; color: #42506a; }
.side-card a { display: block; color: var(--blue); font-weight: 800; margin-top: 10px; }
.download-page .download-btn { margin-top: 8px; }
.site-footer { background: #111827; color: #d6dce8; padding-top: 44px; }
.footer-grid { display: grid; gap: 24px; }
.footer-brand { color: #fff; font-weight: 900; font-size: 22px; margin-bottom: 10px; }
.site-footer h3 { color: #fff; margin: 0 0 12px; font-size: 16px; }
.site-footer p { color: #aeb7c8; margin: 0; }
.site-footer a { display: block; color: #cbd5e1; margin: 8px 0; }
.site-footer a:hover { color: #fff; }
.footer-bottom { margin-top: 34px; padding: 18px 0; border-top: 1px solid rgba(255,255,255,.1); text-align: center; }
.footer-bottom p { font-size: 13px; }
@media (min-width: 700px) {
    .node-overview-grid, .privacy-grid, .policy-grid, .device-grid, .protocol-grid, .risk-grid, .faq-grid { grid-template-columns: repeat(2, 1fr); }
    .speed-grid { grid-template-columns: 1.1fr .9fr; align-items: center; }
    .process-steps { grid-template-columns: repeat(2, 1fr); }
    .footer-grid { grid-template-columns: 1.4fr 1fr 1fr 1fr; }
}
@media (min-width: 960px) {
    .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; padding: 9px 10px; }
    .hero-grid, .split { grid-template-columns: 1.06fr .94fr; }
    .node-overview-grid { grid-template-columns: repeat(4, 1fr); }
    .policy-grid, .protocol-grid { grid-template-columns: repeat(3, 1fr); }
    .risk-grid { grid-template-columns: repeat(4, 1fr); }
    .article-layout { grid-template-columns: minmax(0, 1fr) 320px; align-items: start; }
    .article-sidebar { position: sticky; top: 92px; }
}
@media (max-width: 520px) {
    .container, .header-inner { width: min(100% - 24px, 1120px); }
    .vpn-network-hero { padding-top: 50px; }
    .hero-visual { min-height: 270px; }
    .float-card { position: static; display: inline-flex; margin: 6px; }
    .hero-device { width: 100%; }
    .download-btn { width: 100%; }
    .section { padding: 48px 0; }
    .article-card, .side-card { padding: 20px; }
}