* {
    box-sizing: border-box;
}

:root {
    --primary: #2980FE;
    --primary-hover: #1768E8;
    --gradient: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    --text: #1E2A3A;
    --muted: #667085;
    --soft: #F5F7FB;
    --soft-blue: #F1F6FF;
    --line: #E5EAF3;
    --white: #FFFFFF;
    --shadow: 0 18px 45px rgba(39, 64, 130, .10);
    --radius: 24px;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
    color: var(--text);
    background: #FFFFFF;
    line-height: 1.72;
    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 {
    line-height: 1.25;
    margin: 0 0 16px;
    color: #111827;
}

h1 {
    font-size: clamp(34px, 8vw, 64px);
    letter-spacing: -1.5px;
}

h2 {
    font-size: clamp(26px, 4vw, 42px);
}

h3 {
    font-size: 21px;
}

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

.section {
    padding: 72px 0;
}

.section-soft {
    background: var(--soft);
}

.kicker,
.badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 7px 12px;
    border-radius: 999px;
    color: var(--primary);
    background: #EAF3FF;
    font-weight: 700;
    font-size: 14px;
    margin-bottom: 14px;
}

.lead {
    font-size: 17px;
    color: var(--muted);
    max-width: 760px;
}

.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 13px 24px;
    border-radius: 999px;
    background: #2980FE;
    color: #FFFFFF;
    font-weight: 800;
    box-shadow: 0 14px 26px rgba(41, 128, 254, .26);
    transition: transform .2s ease, background .2s ease, box-shadow .2s ease;
}

.download-btn:hover,
.download-btn:focus {
    background: #1768E8;
    transform: translateY(-2px);
    box-shadow: 0 18px 34px rgba(23, 104, 232, .30);
}

.site-header {
    position: sticky;
    top: 0;
    z-index: 50;
    background: rgba(255, 255, 255, .92);
    backdrop-filter: blur(18px);
    border-bottom: 1px solid rgba(229, 234, 243, .8);
}

.nav-shell {
    width: min(1180px, calc(100% - 28px));
    margin: 0 auto;
    min-height: 70px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
}

.brand,
.footer-brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-weight: 900;
    letter-spacing: .3px;
    color: #172033;
    font-size: 20px;
}

.brand img,
.footer-brand img {
    width: 38px;
    height: 38px;
    border-radius: 12px;
    object-fit: cover;
}

.site-nav {
    display: none;
    position: absolute;
    top: 70px;
    left: 14px;
    right: 14px;
    padding: 14px;
    background: #FFFFFF;
    border: 1px solid var(--line);
    border-radius: 20px;
    box-shadow: var(--shadow);
}

.site-nav a {
    display: block;
    padding: 12px 14px;
    border-radius: 14px;
    color: #344054;
    font-weight: 700;
}

.site-nav a:hover {
    color: var(--primary);
    background: #F1F6FF;
}

.nav-toggle {
    position: absolute;
    opacity: 0;
    pointer-events: none;
}

.nav-toggle-btn {
    width: 44px;
    height: 44px;
    border-radius: 14px;
    border: 1px solid var(--line);
    display: grid;
    place-items: center;
    gap: 4px;
    padding: 10px;
    background: #FFFFFF;
}

.nav-toggle-btn span {
    width: 22px;
    height: 2px;
    background: #1F2937;
    display: block;
    border-radius: 4px;
}

.nav-toggle:checked ~ .site-nav {
    display: block;
}

.vpn-network-hero {
    position: relative;
    overflow: hidden;
    color: #FFFFFF;
    background: var(--gradient);
    padding: 78px 0 52px;
}

.vpn-network-hero::before {
    content: "";
    position: absolute;
    inset: 0;
    background:
        radial-gradient(circle at 14% 20%, rgba(255,255,255,.24), transparent 26%),
        radial-gradient(circle at 88% 18%, rgba(255,255,255,.20), transparent 24%),
        linear-gradient(135deg, rgba(255,255,255,.18) 0 1px, transparent 1px 100%);
    background-size: auto, auto, 46px 46px;
    opacity: .75;
}

.hero-grid {
    position: relative;
    display: grid;
    gap: 40px;
    align-items: center;
}

.hero-copy h1,
.hero-copy p {
    color: #FFFFFF;
}

.hero-copy .lead {
    color: rgba(255,255,255,.88);
    max-width: 650px;
}

.hero-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin: 22px 0 26px;
}

.hero-tags span,
.status-pill {
    display: inline-flex;
    align-items: center;
    padding: 8px 12px;
    border-radius: 999px;
    background: rgba(255,255,255,.17);
    border: 1px solid rgba(255,255,255,.22);
    color: #FFFFFF;
    font-weight: 700;
    font-size: 14px;
}

.hero-visual {
    position: relative;
    min-height: 360px;
    display: grid;
    place-items: center;
}

.hero-device {
    width: min(440px, 92%);
    padding: 18px;
    border-radius: 32px;
    background: rgba(255,255,255,.18);
    border: 1px solid rgba(255,255,255,.24);
    box-shadow: 0 24px 70px rgba(18, 23, 71, .28);
}

.hero-device img {
    border-radius: 24px;
    margin: auto;
}

.floating-card {
    position: absolute;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 11px 14px;
    border-radius: 18px;
    background: rgba(255,255,255,.92);
    color: #1D2939;
    box-shadow: 0 18px 50px rgba(19, 40, 99, .18);
    font-weight: 800;
    font-size: 14px;
}

.floating-card::before {
    content: "";
    width: 9px;
    height: 9px;
    border-radius: 50%;
    background: var(--primary);
}

.floating-card.one { top: 24px; left: 2px; }
.floating-card.two { top: 70px; right: 4px; }
.floating-card.three { bottom: 62px; left: 2px; }
.floating-card.four { bottom: 26px; right: 0; }

.node-overview {
    margin-top: -38px;
    position: relative;
    z-index: 3;
}

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

.node-card,
.feature-card,
.risk-card,
.faq-item,
.info-card,
.step-card {
    background: #FFFFFF;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    box-shadow: 0 12px 34px rgba(28, 50, 92, .06);
}

.node-card {
    padding: 22px;
}

.node-card .tag {
    color: var(--primary);
    font-size: 13px;
    font-weight: 900;
}

.node-card p,
.feature-card p,
.info-card p,
.risk-card p,
.step-card p,
.faq-item p {
    color: var(--muted);
}

.text-link {
    display: inline-flex;
    color: var(--primary);
    font-weight: 800;
    margin-top: 6px;
}

.split-section {
    display: grid;
    gap: 30px;
    align-items: center;
}

.visual-card {
    background: #FFFFFF;
    border: 1px solid var(--line);
    border-radius: 32px;
    box-shadow: var(--shadow);
    padding: 18px;
    overflow: hidden;
}

.visual-card img {
    border-radius: 24px;
    margin: auto;
}

.bullet-list,
.check-list {
    display: grid;
    gap: 10px;
    margin: 22px 0;
    padding: 0;
    list-style: none;
}

.bullet-list li,
.check-list li {
    padding-left: 30px;
    position: relative;
    color: #344054;
}

.bullet-list li::before,
.check-list li::before {
    content: "";
    width: 9px;
    height: 9px;
    border-radius: 999px;
    background: var(--primary);
    position: absolute;
    left: 8px;
    top: 12px;
}

.global-nodes-section {
    position: relative;
    overflow: hidden;
    background: #F6F9FF;
}

.global-nodes-section::before {
    content: "";
    position: absolute;
    inset: 52px 0 auto;
    height: 280px;
    background:
        radial-gradient(circle at 18% 40%, rgba(41,128,254,.18), transparent 6%),
        radial-gradient(circle at 52% 28%, rgba(123,78,241,.16), transparent 7%),
        radial-gradient(circle at 78% 48%, rgba(184,77,218,.14), transparent 7%),
        linear-gradient(90deg, transparent, rgba(41,128,254,.15), transparent);
    opacity: .8;
}

.map-panel {
    position: relative;
    border-radius: 34px;
    background: rgba(255,255,255,.88);
    border: 1px solid var(--line);
    box-shadow: var(--shadow);
    padding: 24px;
}

.node-status-grid {
    display: grid;
    gap: 12px;
    margin-top: 18px;
}

.node-status-grid span {
    padding: 12px 14px;
    border-radius: 16px;
    background: #F1F6FF;
    color: #2754A8;
    font-weight: 800;
}

.high-speed-section {
    background: #F4F8FF;
}

.speed-lines {
    display: grid;
    gap: 14px;
}

.speed-line {
    background: #FFFFFF;
    border: 1px solid var(--line);
    border-radius: 22px;
    padding: 16px;
}

.speed-line strong {
    display: block;
    margin-bottom: 8px;
}

.line-meter {
    height: 8px;
    border-radius: 999px;
    background: #E6EEFB;
    overflow: hidden;
}

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

.privacy-protection-section {
    background: #FFFFFF;
}

.safety-panel {
    border-radius: 30px;
    border: 1px solid var(--line);
    background: linear-gradient(180deg, #FFFFFF 0%, #F7FAFF 100%);
    box-shadow: var(--shadow);
    padding: 24px;
}

.safety-panel img {
    border-radius: 22px;
    margin-bottom: 18px;
}

.panel-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.panel-tags span {
    background: #EAF3FF;
    color: var(--primary);
    padding: 8px 11px;
    border-radius: 999px;
    font-weight: 800;
    font-size: 13px;
}

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

.feature-card {
    padding: 22px;
}

.multi-device-section {
    background: #F7F8FB;
}

.device-grid {
    display: grid;
    gap: 14px;
    margin-top: 20px;
}

.device-item {
    padding: 16px;
    border: 1px solid var(--line);
    border-radius: 20px;
    background: #FFFFFF;
}

.encryption-protocol-section {
    background: #FFFFFF;
}

.tech-panel {
    display: grid;
    gap: 16px;
    padding: 22px;
    border-radius: 30px;
    background: #111827;
    color: #FFFFFF;
    box-shadow: 0 22px 60px rgba(17, 24, 39, .20);
}

.tech-panel h3,
.tech-panel p {
    color: #FFFFFF;
}

.protocol-row {
    display: grid;
    gap: 8px;
    padding: 15px;
    border-radius: 18px;
    background: rgba(255,255,255,.09);
    border: 1px solid rgba(255,255,255,.12);
}

.process-steps {
    display: grid;
    gap: 14px;
    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(--primary);
    color: #FFFFFF;
    font-weight: 900;
    margin-bottom: 12px;
}

.risk-grid {
    display: grid;
    gap: 16px;
    margin-top: 26px;
}

.risk-card {
    padding: 20px;
    border-left: 4px solid var(--primary);
}

.risk-card strong {
    display: block;
    margin: 10px 0 4px;
    color: #344054;
}

.faq-list {
    display: grid;
    gap: 14px;
    margin-top: 26px;
}

.faq-item {
    padding: 20px;
}

.cta-section {
    padding: 72px 0;
    color: #FFFFFF;
    background: var(--gradient);
    text-align: center;
    position: relative;
    overflow: hidden;
}

.cta-section::before {
    content: "";
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at 20% 30%, rgba(255,255,255,.22), transparent 28%),
                radial-gradient(circle at 85% 20%, rgba(255,255,255,.18), transparent 24%);
}

.cta-section .container {
    position: relative;
}

.cta-section h2,
.cta-section p {
    color: #FFFFFF;
}

.page-hero {
    padding: 70px 0 44px;
    background: linear-gradient(180deg, #F6F9FF 0%, #FFFFFF 100%);
}

.page-hero .lead {
    max-width: 780px;
}

.content-layout {
    display: grid;
    gap: 28px;
    align-items: start;
}

.article-card {
    background: #FFFFFF;
    border: 1px solid var(--line);
    border-radius: 30px;
    padding: 24px;
    box-shadow: 0 12px 36px rgba(28, 50, 92, .06);
}

.article-card h2 {
    font-size: 28px;
}

.side-panel {
    display: grid;
    gap: 16px;
}

.info-card {
    padding: 20px;
}

.install-steps {
    counter-reset: install;
    list-style: none;
    padding: 0;
    margin: 22px 0;
    display: grid;
    gap: 14px;
}

.install-steps li {
    counter-increment: install;
    padding: 18px 18px 18px 60px;
    border: 1px solid var(--line);
    background: #FFFFFF;
    border-radius: 20px;
    position: relative;
}

.install-steps li::before {
    content: counter(install);
    position: absolute;
    left: 18px;
    top: 18px;
    width: 30px;
    height: 30px;
    display: grid;
    place-items: center;
    border-radius: 11px;
    background: var(--primary);
    color: #FFFFFF;
    font-weight: 900;
}

.download-page-panel {
    max-width: 900px;
    margin: 0 auto;
    text-align: center;
}

.download-page-panel .download-btn {
    margin: 10px 0 26px;
}

.site-footer {
    background: #101828;
    color: rgba(255,255,255,.76);
    padding: 54px 0 0;
}

.footer-grid {
    display: grid;
    gap: 28px;
}

.site-footer h3 {
    color: #FFFFFF;
    font-size: 17px;
}

.site-footer a {
    display: block;
    color: rgba(255,255,255,.72);
    margin: 8px 0;
}

.site-footer a:hover {
    color: #FFFFFF;
}

.footer-brand {
    color: #FFFFFF;
    margin-bottom: 14px;
}

.footer-bottom {
    margin-top: 36px;
    border-top: 1px solid rgba(255,255,255,.12);
    padding: 18px 16px;
    text-align: center;
    color: rgba(255,255,255,.62);
}

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

    .process-steps {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .node-status-grid,
    .device-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

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

@media (min-width: 900px) {
    .site-nav {
        display: flex;
        position: static;
        padding: 0;
        border: 0;
        box-shadow: none;
        background: transparent;
        gap: 2px;
    }

    .site-nav a {
        display: inline-flex;
        padding: 10px 12px;
    }

    .nav-toggle-btn {
        display: none;
    }

    .vpn-network-hero {
        padding: 100px 0 76px;
    }

    .hero-grid,
    .split-section {
        grid-template-columns: minmax(0, 1fr) minmax(360px, .92fr);
    }

    .split-section.reverse {
        grid-template-columns: minmax(360px, .92fr) minmax(0, 1fr);
    }

    .split-section.reverse .visual-card,
    .split-section.reverse .map-panel {
        order: -1;
    }

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

    .feature-grid {
        grid-template-columns: repeat(3, minmax(0, 1fr));
    }

    .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;
    }

    .footer-grid {
        grid-template-columns: 1.5fr 1fr 1fr 1fr;
    }
}

@media (min-width: 1120px) {
    .hero-copy {
        padding-right: 34px;
    }

    .section {
        padding: 92px 0;
    }
}

@media (max-width: 430px) {
    .container {
        width: min(100% - 24px, 1120px);
    }

    .download-btn {
        width: 100%;
    }

    .floating-card {
        position: static;
        margin: 8px;
    }

    .hero-visual {
        display: flex;
        flex-wrap: wrap;
        min-height: auto;
    }

    .hero-device {
        order: -1;
        width: 100%;
        margin-bottom: 8px;
    }
}