* {
    box-sizing: border-box;
}
:root {
    --blue: #2980FE;
    --blue-dark: #1768E8;
    --text: #1f2937;
    --muted: #667085;
    --soft: #f5f7fb;
    --line: #e6eaf2;
    --deep: #111827;
    --gradient: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    --radius: 24px;
    --shadow: 0 18px 40px rgba(22, 34, 66, .10);
}
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%; height: auto; display: block; }
p { margin: 0 0 16px; color: var(--muted); }
h1, h2, h3 { margin: 0 0 14px; color: var(--deep); line-height: 1.2; }
h1 { font-size: clamp(34px, 8vw, 62px); letter-spacing: -1.4px; }
h2 { font-size: clamp(26px, 5vw, 42px); letter-spacing: -0.6px; }
h3 { font-size: 20px; }
ul, ol { padding-left: 20px; color: var(--muted); }
.container { width: min(1120px, calc(100% - 32px)); margin: 0 auto; }
.section { padding: 68px 0; }
.section-soft { background: var(--soft); }
.section-title { max-width: 760px; margin-bottom: 30px; }
.eyebrow, .badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 7px 12px;
    border-radius: 999px;
    background: rgba(41, 128, 254, .10);
    color: var(--blue);
    font-weight: 700;
    font-size: 14px;
    margin-bottom: 14px;
}
.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 13px 24px;
    border-radius: 999px;
    color: #fff;
    background: var(--blue);
    font-weight: 800;
    box-shadow: 0 12px 26px rgba(41, 128, 254, .25);
    transition: background .2s ease, transform .2s ease, box-shadow .2s ease;
}
.download-btn:hover { background: var(--blue-dark); transform: translateY(-2px); box-shadow: 0 16px 32px rgba(23, 104, 232, .26); }
.link-more { color: var(--blue); font-weight: 800; }
.site-header {
    position: sticky;
    top: 0;
    z-index: 30;
    background: rgba(255,255,255,.92);
    backdrop-filter: blur(14px);
    border-bottom: 1px solid var(--line);
}
.header-inner {
    width: min(1180px, calc(100% - 28px));
    margin: 0 auto;
    min-height: 72px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
}
.logo { display: inline-flex; align-items: center; gap: 10px; font-weight: 900; font-size: 20px; color: var(--deep); }
.logo img { width: 38px; height: 38px; border-radius: 12px; object-fit: cover; }
.site-nav { display: none; flex-direction: column; gap: 10px; position: absolute; left: 14px; right: 14px; top: 72px; background: #fff; padding: 18px; border-radius: 18px; border: 1px solid var(--line); box-shadow: var(--shadow); }
.site-nav a { color: #344054; font-weight: 700; padding: 9px 10px; border-radius: 12px; }
.site-nav a.active, .site-nav a:hover { color: var(--blue); background: rgba(41,128,254,.08); }
.nav-toggle { display: none; }
.nav-toggle-label { width: 42px; height: 42px; display: grid; place-content: center; gap: 5px; border-radius: 14px; border: 1px solid var(--line); }
.nav-toggle-label span { width: 20px; height: 2px; background: var(--deep); display: block; border-radius: 999px; }
.nav-toggle:checked ~ .site-nav { display: flex; }
.vpn-network-hero {
    position: relative;
    overflow: hidden;
    background: var(--gradient);
    color: #fff;
    padding: 74px 0 56px;
}
.vpn-network-hero::before {
    content: "";
    position: absolute;
    inset: 0;
    background-image: radial-gradient(circle at 20% 25%, rgba(255,255,255,.24) 0 2px, transparent 3px), radial-gradient(circle at 70% 45%, rgba(255,255,255,.18) 0 2px, transparent 3px), linear-gradient(135deg, transparent 0 44%, rgba(255,255,255,.16) 45%, transparent 46% 100%);
    background-size: 160px 160px, 220px 220px, 100% 100%;
    opacity: .75;
}
.hero-grid { position: relative; display: grid; gap: 36px; align-items: center; }
.hero-copy h1, .hero-copy p { color: #fff; }
.hero-copy p { font-size: 18px; max-width: 650px; opacity: .92; }
.hero-tags { display: flex; flex-wrap: wrap; gap: 10px; margin: 20px 0 26px; }
.hero-tags span { padding: 8px 12px; border-radius: 999px; background: rgba(255,255,255,.16); border: 1px solid rgba(255,255,255,.24); font-weight: 700; }
.hero-visual { position: relative; min-height: 320px; display: grid; place-items: center; }
.hero-device { width: min(420px, 86%); padding: 18px; border-radius: 32px; background: rgba(255,255,255,.16); border: 1px solid rgba(255,255,255,.25); box-shadow: 0 28px 70px rgba(21, 31, 80, .28); }
.hero-device img { border-radius: 24px; width: 100%; object-fit: cover; }
.status-chip { position: absolute; padding: 10px 14px; border-radius: 16px; background: rgba(255,255,255,.92); color: var(--deep); font-weight: 800; box-shadow: var(--shadow); font-size: 14px; }
.chip-one { left: 2%; top: 14%; }
.chip-two { right: 0; top: 18%; }
.chip-three { left: 8%; bottom: 14%; }
.chip-four { right: 10%; bottom: 8%; }
.node-overview { margin-top: -34px; position: relative; z-index: 2; }
.node-grid, .card-grid, .risk-grid, .faq-grid { display: grid; grid-template-columns: 1fr; gap: 18px; }
.node-card, .info-card, .risk-card, .faq-item, .step-card, .policy-card {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 24px;
    box-shadow: 0 12px 28px rgba(18, 35, 80, .06);
}
.node-card strong { display: inline-block; color: var(--blue); margin-bottom: 8px; }
.feature-split, .image-split, .privacy-panel, .device-layout, .protocol-layout, .speed-layout, .nodes-layout, .page-layout, .about-grid, .download-layout {
    display: grid;
    grid-template-columns: 1fr;
    gap: 28px;
    align-items: center;
}
.image-panel, .visual-card {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 32px;
    padding: 18px;
    box-shadow: var(--shadow);
}
.image-panel img, .visual-card img { border-radius: 24px; width: 100%; object-fit: cover; }
.points { display: grid; gap: 12px; margin: 22px 0; }
.points span, .mini-tag {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 12px;
    border-radius: 14px;
    background: #f4f8ff;
    color: #344054;
    border: 1px solid #dbe8ff;
    font-weight: 700;
}
.global-nodes-section {
    position: relative;
    overflow: hidden;
    background: #f8fbff;
}
.map-card {
    position: relative;
    min-height: 350px;
    border-radius: 32px;
    padding: 20px;
    background: radial-gradient(circle at 35% 35%, rgba(41,128,254,.22), transparent 30%), radial-gradient(circle at 72% 55%, rgba(123,78,241,.18), transparent 28%), #fff;
    border: 1px solid var(--line);
    box-shadow: var(--shadow);
    overflow: hidden;
}
.map-card::after { content: ""; position: absolute; inset: 24px; border: 1px dashed rgba(41,128,254,.28); border-radius: 26px; }
.map-card img { position: relative; z-index: 1; border-radius: 24px; }
.node-pins { position: relative; z-index: 2; display: grid; gap: 10px; margin-top: 16px; }
.node-pins span { background: #fff; border: 1px solid var(--line); border-left: 4px solid var(--blue); border-radius: 14px; padding: 10px 12px; font-weight: 800; }
.speed-lines { display: grid; gap: 14px; margin: 20px 0; }
.speed-line { padding: 16px; border-radius: 18px; background: #fff; border: 1px solid var(--line); }
.speed-line b { display: flex; justify-content: space-between; color: var(--deep); }
.speed-line i { display: block; height: 8px; border-radius: 999px; background: var(--gradient); margin-top: 12px; }
.safe-panel { background: #fff; border: 1px solid var(--line); border-radius: 32px; padding: 26px; box-shadow: var(--shadow); }
.safe-panel .mini-tag { margin: 6px 6px 0 0; }
.policy-grid { display: grid; grid-template-columns: 1fr; gap: 18px; }
.policy-card { border-top: 4px solid var(--blue); }
.device-cards { display: grid; grid-template-columns: 1fr; gap: 14px; }
.device-card { padding: 18px; border-radius: 20px; border: 1px solid var(--line); background: #fff; }
.protocol-stack { display: grid; gap: 14px; }
.protocol-item { display: grid; gap: 8px; padding: 18px; border-radius: 20px; background: #fff; border: 1px solid var(--line); }
.process-steps { display: grid; grid-template-columns: 1fr; gap: 16px; }
.step-number { width: 38px; height: 38px; display: grid; place-items: center; border-radius: 50%; background: var(--blue); color: #fff; font-weight: 900; margin-bottom: 12px; }
.risk-card { border-left: 4px solid var(--blue); }
.faq-item details { display: block; }
.faq-item summary { cursor: pointer; font-weight: 900; color: var(--deep); }
.faq-item p { margin-top: 12px; }
.cta-section { background: var(--gradient); color: #fff; text-align: center; padding: 72px 0; }
.cta-section h2, .cta-section p { color: #fff; }
.cta-section p { max-width: 700px; margin: 0 auto 24px; opacity: .92; }
.page-hero { background: linear-gradient(180deg, #f7faff 0%, #fff 100%); padding: 58px 0 30px; }
.page-hero .summary { font-size: 18px; max-width: 800px; }
.page-content { padding: 36px 0 70px; }
.article-card { background: #fff; border: 1px solid var(--line); border-radius: 28px; padding: 26px; box-shadow: 0 12px 28px rgba(18, 35, 80, .06); }
.side-panel { align-self: start; background: #f8fbff; border: 1px solid #dbe8ff; border-radius: 28px; padding: 22px; }
.side-panel a { display: block; color: var(--blue); font-weight: 800; padding: 8px 0; }
.notice-box { margin: 20px 0; padding: 18px; border-radius: 20px; background: #f4f8ff; border: 1px solid #dbe8ff; }
.check-list { display: grid; gap: 12px; margin: 20px 0; }
.check-list li { background: #fff; border: 1px solid var(--line); border-radius: 16px; padding: 12px 14px; list-style-position: inside; }
.download-layout { align-items: start; }
.download-steps { counter-reset: dl; display: grid; gap: 14px; }
.download-steps li { list-style: none; padding: 16px; border-radius: 18px; background: #fff; border: 1px solid var(--line); }
.about-card { background: #fff; border: 1px solid var(--line); border-radius: 26px; padding: 24px; }
.site-footer { background: #101828; color: #d0d5dd; padding: 54px 0 0; }
.site-footer p, .site-footer a { color: #d0d5dd; }
.site-footer h3 { color: #fff; font-size: 16px; }
.footer-grid { display: grid; gap: 28px; grid-template-columns: 1fr; }
.footer-grid a { display: block; margin: 8px 0; }
.footer-brand { display: flex; align-items: center; gap: 10px; color: #fff; font-size: 20px; margin-bottom: 12px; }
.footer-brand img { width: 38px; height: 38px; border-radius: 12px; object-fit: cover; }
.footer-bottom { margin-top: 34px; padding: 18px; text-align: center; border-top: 1px solid rgba(255,255,255,.10); color: #98a2b3; font-size: 14px; }
@media (min-width: 640px) {
    .node-grid, .card-grid, .risk-grid, .faq-grid, .policy-grid, .process-steps, .device-cards { grid-template-columns: repeat(2, 1fr); }
}
@media (min-width: 900px) {
    .site-nav { display: flex; position: static; flex-direction: row; align-items: center; gap: 3px; background: transparent; padding: 0; border: 0; box-shadow: none; }
    .nav-toggle-label { display: none; }
    .hero-grid, .feature-split, .image-split, .privacy-panel, .device-layout, .protocol-layout, .speed-layout, .nodes-layout, .download-layout { grid-template-columns: 1.05fr .95fr; }
    .page-layout { grid-template-columns: minmax(0, 1fr) 310px; align-items: start; }
    .node-grid { grid-template-columns: repeat(4, 1fr); }
    .risk-grid { grid-template-columns: repeat(3, 1fr); }
    .process-steps { grid-template-columns: repeat(3, 1fr); }
    .footer-grid { grid-template-columns: 1.4fr 1fr 1fr 1fr; }
    .section { padding: 86px 0; }
    .vpn-network-hero { padding: 100px 0 80px; }
}
@media (min-width: 1100px) {
    .about-grid { grid-template-columns: repeat(3, 1fr); }
}
@media (max-width: 420px) {
    .container { width: min(100% - 24px, 1120px); }
    .download-btn { width: 100%; }
    .status-chip { position: static; margin: 8px; display: inline-flex; }
    .hero-visual { display: block; min-height: 0; text-align: center; }
    .hero-device { margin: 0 auto 14px; }
}