:root {
    --blue: #2980FE;
    --blue-dark: #1768E8;
    --gradient: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    --text: #1F2937;
    --muted: #667085;
    --light: #F5F7FB;
    --soft: #EEF4FF;
    --border: #E5EAF3;
    --white: #FFFFFF;
    --shadow: 0 18px 45px rgba(31, 41, 55, 0.10);
    --radius-lg: 28px;
    --radius-md: 20px;
    --radius-sm: 14px;
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
    color: var(--text);
    background: #fff;
    line-height: 1.7;
    overflow-x: hidden;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

a {
    color: inherit;
    text-decoration: none;
}

p {
    margin: 0 0 16px;
}

h1, h2, h3 {
    margin: 0 0 16px;
    line-height: 1.18;
    letter-spacing: -0.02em;
}

h1 {
    font-size: clamp(34px, 7vw, 64px);
}

h2 {
    font-size: clamp(28px, 5vw, 44px);
}

h3 {
    font-size: 20px;
}

.site-header {
    position: sticky;
    top: 0;
    z-index: 50;
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid rgba(229, 234, 243, 0.85);
}

.header-inner {
    width: min(1180px, calc(100% - 32px));
    margin: 0 auto;
    min-height: 72px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-weight: 800;
    color: #152033;
    white-space: nowrap;
}

.brand-logo {
    width: 42px;
    height: 42px;
    border-radius: 14px;
    object-fit: cover;
    box-shadow: 0 8px 24px rgba(41, 128, 254, 0.20);
}

.brand-text {
    font-size: 17px;
}

.desktop-nav {
    display: none;
    align-items: center;
    gap: 4px;
    font-size: 14px;
    color: #344054;
}

.desktop-nav a {
    padding: 10px 12px;
    border-radius: 999px;
}

.desktop-nav a:hover,
.desktop-nav a.active {
    color: var(--blue);
    background: rgba(41, 128, 254, 0.08);
}

.mobile-nav {
    position: relative;
}

.mobile-nav summary {
    list-style: none;
    cursor: pointer;
    border: 1px solid var(--border);
    color: var(--blue);
    padding: 8px 14px;
    border-radius: 999px;
    font-weight: 700;
}

.mobile-nav summary::-webkit-details-marker {
    display: none;
}

.mobile-nav-panel {
    position: absolute;
    right: 0;
    top: 46px;
    width: min(280px, calc(100vw - 32px));
    background: #fff;
    border: 1px solid var(--border);
    border-radius: 18px;
    box-shadow: var(--shadow);
    padding: 10px;
    display: grid;
    gap: 4px;
}

.mobile-nav-panel a {
    padding: 10px 12px;
    color: #344054;
    border-radius: 12px;
}

.mobile-nav-panel a:hover {
    background: var(--soft);
    color: var(--blue);
}

.content-container,
.section-inner {
    width: min(1120px, calc(100% - 32px));
    margin: 0 auto;
}

.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: 800;
    line-height: 1;
    box-shadow: 0 14px 30px rgba(41, 128, 254, 0.25);
    transition: transform .2s ease, background .2s ease, box-shadow .2s ease;
}

.download-btn:hover {
    background: #1768E8;
    transform: translateY(-2px);
    box-shadow: 0 18px 36px rgba(23, 104, 232, 0.28);
}

.text-link {
    color: var(--blue);
    font-weight: 700;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

.text-link::after {
    content: "→";
}

.badge {
    display: inline-flex;
    align-items: center;
    width: fit-content;
    padding: 7px 12px;
    border-radius: 999px;
    background: rgba(41, 128, 254, 0.10);
    color: var(--blue);
    font-weight: 800;
    font-size: 13px;
    margin-bottom: 16px;
}

.section-kicker {
    color: var(--blue);
    font-weight: 800;
    margin-bottom: 8px;
}

.section-muted {
    color: var(--muted);
}

.vpn-network-hero {
    position: relative;
    overflow: hidden;
    color: #fff;
    background: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
}

.vpn-network-hero::before,
.vpn-network-hero::after {
    content: "";
    position: absolute;
    inset: auto;
    border-radius: 999px;
    filter: blur(10px);
    opacity: .35;
    pointer-events: none;
}

.vpn-network-hero::before {
    width: 420px;
    height: 420px;
    left: -130px;
    top: -160px;
    background: rgba(255, 255, 255, .28);
}

.vpn-network-hero::after {
    width: 360px;
    height: 360px;
    right: -130px;
    bottom: -120px;
    background: rgba(255, 255, 255, .18);
}

.hero-inner {
    position: relative;
    z-index: 2;
    width: min(1180px, calc(100% - 32px));
    margin: 0 auto;
    padding: 72px 0 56px;
    display: grid;
    gap: 38px;
}

.hero-copy {
    max-width: 680px;
}

.hero-copy p {
    color: rgba(255, 255, 255, 0.86);
    font-size: 17px;
}

.hero-tags,
.status-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin: 20px 0 28px;
}

.hero-tags span,
.status-tags span {
    border: 1px solid rgba(255, 255, 255, 0.25);
    background: rgba(255, 255, 255, 0.12);
    color: #fff;
    padding: 7px 11px;
    border-radius: 999px;
    font-size: 13px;
}

.hero-visual {
    position: relative;
    min-height: 340px;
}

.hero-orbit {
    position: absolute;
    inset: 0;
    border-radius: 36px;
    background:
        radial-gradient(circle at 20% 25%, rgba(255,255,255,.38) 0 2px, transparent 3px),
        radial-gradient(circle at 76% 34%, rgba(255,255,255,.28) 0 3px, transparent 4px),
        radial-gradient(circle at 45% 72%, rgba(255,255,255,.30) 0 2px, transparent 3px),
        linear-gradient(135deg, rgba(255,255,255,.15), rgba(255,255,255,.05));
    border: 1px solid rgba(255, 255, 255, 0.20);
}

.hero-orbit::before {
    content: "";
    position: absolute;
    inset: 22px;
    border-radius: 30px;
    border: 1px dashed rgba(255,255,255,.28);
}

.hero-img-card {
    position: relative;
    margin: 26px auto 0;
    width: min(440px, 86%);
    padding: 18px;
    border-radius: 34px;
    background: rgba(255,255,255,.16);
    border: 1px solid rgba(255,255,255,.25);
    box-shadow: 0 25px 60px rgba(0,0,0,.14);
    backdrop-filter: blur(12px);
}

.hero-img-card img {
    border-radius: 26px;
}

.float-card {
    position: absolute;
    z-index: 3;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 13px;
    border-radius: 16px;
    background: rgba(255, 255, 255, 0.92);
    color: #1F2937;
    box-shadow: 0 16px 38px rgba(31, 41, 55, .18);
    font-weight: 800;
    font-size: 13px;
}

.float-card::before {
    content: "";
    width: 8px;
    height: 8px;
    border-radius: 99px;
    background: var(--blue);
}

.float-card.one { top: 20px; left: 10px; }
.float-card.two { top: 86px; right: 0; }
.float-card.three { bottom: 68px; left: 0; }
.float-card.four { bottom: 14px; right: 20px; }

.section {
    padding: 72px 0;
}

.section.alt {
    background: #F7FAFF;
}

.node-overview {
    margin-top: -32px;
    position: relative;
    z-index: 4;
}

.node-grid {
    display: grid;
    gap: 16px;
}

.node-card,
.feature-card,
.info-card,
.risk-card,
.faq-item,
.step-card {
    background: var(--white);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    box-shadow: 0 12px 35px rgba(31, 41, 55, 0.06);
}

.node-card {
    padding: 24px;
}

.node-card .tag {
    display: inline-flex;
    padding: 4px 9px;
    border-radius: 999px;
    background: rgba(41, 128, 254, 0.10);
    color: var(--blue);
    font-size: 12px;
    font-weight: 800;
    margin-bottom: 12px;
}

.split-section,
.vpn-connection-section,
.privacy-protection-section,
.multi-device-section,
.encryption-protocol-section,
.high-speed-layout {
    display: grid;
    gap: 28px;
    align-items: center;
}

.image-panel {
    border-radius: var(--radius-lg);
    background: linear-gradient(180deg, #fff, #F5F8FF);
    border: 1px solid var(--border);
    padding: 18px;
    box-shadow: var(--shadow);
}

.image-panel img {
    border-radius: 22px;
}

.bullet-list {
    display: grid;
    gap: 12px;
    margin: 22px 0;
    padding: 0;
    list-style: none;
}

.bullet-list li {
    position: relative;
    padding-left: 26px;
    color: #344054;
}

.bullet-list li::before {
    content: "";
    position: absolute;
    top: 12px;
    left: 0;
    width: 9px;
    height: 9px;
    border-radius: 999px;
    background: var(--blue);
    box-shadow: 0 0 0 5px rgba(41,128,254,.10);
}

.global-nodes-section {
    position: relative;
    overflow: hidden;
    border-radius: 34px;
    background:
        radial-gradient(circle at 18% 28%, rgba(41,128,254,.18) 0 3px, transparent 4px),
        radial-gradient(circle at 78% 32%, rgba(123,78,241,.18) 0 3px, transparent 4px),
        radial-gradient(circle at 52% 78%, rgba(184,77,218,.16) 0 3px, transparent 4px),
        linear-gradient(135deg, #FFFFFF 0%, #F0F5FF 100%);
    border: 1px solid var(--border);
    padding: 28px;
}

.global-nodes-section::before {
    content: "";
    position: absolute;
    inset: 20px;
    border-radius: 28px;
    border: 1px dashed rgba(41, 128, 254, .22);
    pointer-events: none;
}

.node-map-content {
    position: relative;
    z-index: 2;
    display: grid;
    gap: 26px;
    align-items: center;
}

.map-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin: 20px 0;
}

.map-tags span {
    padding: 7px 11px;
    border-radius: 999px;
    background: #fff;
    border: 1px solid var(--border);
    color: #344054;
    font-weight: 700;
    font-size: 13px;
}

.speed-card {
    padding: 24px;
    background: #fff;
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
}

.speed-lines {
    display: grid;
    gap: 12px;
    margin: 24px 0;
}

.speed-line {
    background: #F2F6FF;
    border-radius: 999px;
    overflow: hidden;
    height: 12px;
}

.speed-line span {
    display: block;
    height: 100%;
    background: var(--gradient);
    border-radius: 999px;
}

.speed-line.one span { width: 86%; }
.speed-line.two span { width: 68%; }
.speed-line.three span { width: 76%; }

.safety-panel {
    padding: 26px;
    border-radius: var(--radius-lg);
    background: #fff;
    border: 1px solid var(--border);
    box-shadow: var(--shadow);
}

.safety-panel .mini-grid {
    display: grid;
    gap: 12px;
    margin-top: 18px;
}

.safety-panel .mini-grid span {
    display: block;
    padding: 13px 14px;
    border-radius: 14px;
    background: #F7FAFF;
    border: 1px solid var(--border);
    color: #344054;
}

.no-log-policy-section .policy-grid,
.feature-grid,
.protocol-grid {
    display: grid;
    gap: 16px;
}

.info-card,
.feature-card {
    padding: 24px;
}

.device-list {
    display: grid;
    gap: 12px;
    margin-top: 20px;
}

.device-item {
    padding: 16px;
    border-radius: 18px;
    background: #F7FAFF;
    border: 1px solid var(--border);
}

.protocol-panel {
    border-radius: 30px;
    background: #152033;
    color: #fff;
    padding: 26px;
    overflow: hidden;
    position: relative;
}

.protocol-panel::after {
    content: "";
    position: absolute;
    right: -80px;
    top: -80px;
    width: 210px;
    height: 210px;
    border-radius: 999px;
    background: rgba(41,128,254,.35);
    filter: blur(6px);
}

.protocol-panel > * {
    position: relative;
    z-index: 2;
}

.protocol-panel .protocol-grid {
    margin-top: 20px;
}

.protocol-panel .feature-card {
    background: rgba(255,255,255,.10);
    border-color: rgba(255,255,255,.14);
    box-shadow: none;
}

.protocol-panel p,
.protocol-panel .section-muted {
    color: rgba(255,255,255,.76);
}

.process-steps {
    display: grid;
    gap: 16px;
    counter-reset: step;
}

.step-card {
    padding: 22px;
    position: relative;
}

.step-number {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 34px;
    height: 34px;
    border-radius: 999px;
    background: var(--blue);
    color: #fff;
    font-weight: 800;
    margin-bottom: 12px;
}

.risk-grid {
    display: grid;
    gap: 16px;
}

.risk-card {
    padding: 22px;
    border-left: 4px solid var(--blue);
}

.risk-card strong {
    display: block;
    margin-bottom: 8px;
}

.faq-list {
    display: grid;
    gap: 14px;
}

.faq-item {
    padding: 22px;
}

.faq-item h3 {
    margin-bottom: 8px;
}

.cta-section {
    padding: 72px 0;
    background: var(--gradient);
    color: #fff;
    text-align: center;
}

.cta-card {
    width: min(860px, calc(100% - 32px));
    margin: 0 auto;
}

.cta-card p {
    color: rgba(255,255,255,.84);
}

.page-hero {
    background: linear-gradient(180deg, #F4F7FF 0%, #FFFFFF 100%);
    padding: 58px 0 34px;
}

.page-hero-inner {
    width: min(980px, calc(100% - 32px));
    margin: 0 auto;
}

.page-hero p {
    color: var(--muted);
    font-size: 17px;
}

.content-layout {
    width: min(1120px, calc(100% - 32px));
    margin: 0 auto;
    padding: 46px 0 72px;
    display: grid;
    gap: 24px;
}

.article-card {
    background: #fff;
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 26px;
    box-shadow: 0 18px 40px rgba(31,41,55,.06);
}

.article-card h2 {
    font-size: clamp(24px, 4vw, 34px);
}

.side-panel {
    background: #F7FAFF;
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: 22px;
    align-self: start;
}

.check-list,
.number-list {
    margin: 18px 0;
    padding-left: 20px;
    color: #344054;
}

.check-list li,
.number-list li {
    margin: 8px 0;
}

.callout {
    margin: 24px 0;
    padding: 18px;
    border-radius: 18px;
    border: 1px solid #D8E6FF;
    background: #F4F8FF;
}

.page-actions {
    margin-top: 26px;
}

.download-steps {
    display: grid;
    gap: 16px;
    margin: 26px 0;
}

.download-step {
    padding: 18px;
    border: 1px solid var(--border);
    border-radius: 18px;
    background: #fff;
}

.site-footer {
    background: #111827;
    color: #fff;
}

.footer-inner {
    width: min(1120px, calc(100% - 32px));
    margin: 0 auto;
    padding: 42px 0;
    display: grid;
    gap: 22px;
}

.footer-brand {
    display: flex;
    gap: 14px;
    align-items: center;
}

.footer-brand img {
    width: 44px;
    height: 44px;
    border-radius: 14px;
    object-fit: cover;
}

.footer-brand p,
.footer-note {
    color: rgba(255,255,255,.68);
    margin: 4px 0 0;
}

.footer-links {
    display: flex;
    flex-wrap: wrap;
    gap: 10px 18px;
}

.footer-links a {
    color: rgba(255,255,255,.78);
}

.footer-links a:hover {
    color: #fff;
}

@media (min-width: 640px) {
    .node-grid,
    .policy-grid,
    .feature-grid,
    .risk-grid,
    .protocol-grid,
    .process-steps,
    .download-steps {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .article-card {
        padding: 34px;
    }
}

@media (min-width: 900px) {
    .desktop-nav {
        display: flex;
    }

    .mobile-nav {
        display: none;
    }

    .hero-inner {
        grid-template-columns: 1.02fr .98fr;
        align-items: center;
        padding: 96px 0 88px;
    }

    .node-grid {
        grid-template-columns: repeat(4, minmax(0, 1fr));
    }

    .split-section,
    .vpn-connection-section,
    .privacy-protection-section,
    .multi-device-section,
    .encryption-protocol-section,
    .high-speed-layout,
    .node-map-content {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .no-log-policy-section .policy-grid,
    .risk-grid {
        grid-template-columns: repeat(3, 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: 42px;
    }
}

@media (min-width: 1120px) {
    .protocol-panel {
        padding: 38px;
    }

    .global-nodes-section {
        padding: 42px;
    }
}

@media (max-width: 380px) {
    .header-inner,
    .content-container,
    .section-inner,
    .hero-inner,
    .page-hero-inner,
    .content-layout {
        width: min(100% - 24px, 1120px);
    }

    .download-btn {
        width: 100%;
    }

    .brand-text {
        font-size: 15px;
    }
}