* {
    box-sizing: border-box;
}

:root {
    --gradient: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    --blue: #2980FE;
    --blue-hover: #1768E8;
    --text: #202635;
    --muted: #687082;
    --light: #F5F7FB;
    --line: #E5E9F2;
    --panel: #FFFFFF;
    --soft-blue: #EEF5FF;
    --radius-lg: 28px;
    --radius-md: 20px;
    --shadow: 0 18px 55px rgba(33, 49, 86, .10);
}

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: 1.7;
    overflow-x: hidden;
}

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

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

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

.section {
    padding: 64px 0;
}

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

.section-eyebrow,
.page-badge,
.card-tag,
.hero-chip {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    color: #155BD8;
    background: #EAF3FF;
    border: 1px solid #D7E7FF;
    border-radius: 999px;
    padding: 6px 12px;
    font-size: 13px;
    font-weight: 700;
}

h1,
h2,
h3 {
    margin: 0;
    line-height: 1.22;
    color: var(--text);
}

h1 {
    font-size: clamp(34px, 8vw, 62px);
    letter-spacing: -1.5px;
}

h2 {
    font-size: clamp(26px, 5vw, 42px);
    letter-spacing: -0.8px;
}

h3 {
    font-size: 21px;
}

p {
    color: var(--muted);
    margin: 14px 0 0;
}

.site-header {
    position: sticky;
    top: 0;
    z-index: 50;
    background: rgba(255, 255, 255, .92);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid rgba(229, 233, 242, .85);
}

.nav-shell {
    width: min(1180px, calc(100% - 28px));
    height: 72px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-weight: 800;
    color: #172033;
    white-space: nowrap;
}

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

.site-nav {
    position: absolute;
    left: 14px;
    right: 14px;
    top: 72px;
    display: none;
    flex-direction: column;
    gap: 4px;
    padding: 14px;
    border-radius: 20px;
    background: #fff;
    box-shadow: var(--shadow);
    border: 1px solid var(--line);
}

.site-nav.open {
    display: flex;
}

.site-nav a {
    padding: 10px 12px;
    border-radius: 12px;
    color: #4B5567;
    font-size: 15px;
    font-weight: 650;
}

.site-nav a:hover,
.site-nav a.active {
    color: #155BD8;
    background: #EEF5FF;
}

.nav-toggle {
    width: 42px;
    height: 42px;
    border: 1px solid var(--line);
    border-radius: 14px;
    background: #fff;
    display: inline-flex;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    padding: 0 10px;
}

.nav-toggle span {
    height: 2px;
    background: #263247;
    border-radius: 999px;
}

.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;
    border: 0;
    box-shadow: 0 12px 28px rgba(41, 128, 254, .28);
    transition: transform .2s ease, background .2s ease, box-shadow .2s ease;
}

.download-btn:hover {
    background: #1768E8;
    transform: translateY(-2px);
    box-shadow: 0 16px 34px rgba(23, 104, 232, .32);
}

.link-more {
    display: inline-flex;
    margin-top: 18px;
    color: #1768E8;
    font-weight: 800;
}

.link-more:hover {
    text-decoration: underline;
}

.vpn-network-hero {
    position: relative;
    min-height: 720px;
    padding: 72px 0 54px;
    background: var(--gradient);
    overflow: hidden;
}

.vpn-network-hero::before,
.vpn-network-hero::after {
    content: "";
    position: absolute;
    inset: auto;
    border-radius: 999px;
    pointer-events: none;
}

.vpn-network-hero::before {
    width: 420px;
    height: 420px;
    right: -120px;
    top: 40px;
    background: rgba(255, 255, 255, .18);
    filter: blur(10px);
}

.vpn-network-hero::after {
    width: 620px;
    height: 620px;
    left: -260px;
    bottom: -240px;
    background: rgba(255, 255, 255, .10);
}

.hero-grid {
    position: relative;
    z-index: 1;
    display: grid;
    gap: 34px;
    align-items: center;
}

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

.hero-copy p {
    max-width: 680px;
    color: rgba(255, 255, 255, .86);
    font-size: 17px;
}

.hero-actions {
    margin-top: 26px;
    display: flex;
    flex-wrap: wrap;
    gap: 14px;
    align-items: center;
}

.hero-tags {
    margin-top: 24px;
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.hero-chip {
    color: #fff;
    background: rgba(255, 255, 255, .14);
    border-color: rgba(255, 255, 255, .24);
    backdrop-filter: blur(8px);
}

.hero-visual {
    position: relative;
    min-height: 390px;
    padding: 20px;
}

.hero-device {
    position: relative;
    z-index: 2;
    width: min(440px, 92%);
    margin: 0 auto;
    border-radius: 32px;
    background: rgba(255, 255, 255, .18);
    border: 1px solid rgba(255, 255, 255, .28);
    padding: 16px;
    box-shadow: 0 30px 80px rgba(12, 23, 70, .22);
}

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

.node-lines {
    position: absolute;
    inset: 0;
    background:
        radial-gradient(circle at 22% 22%, rgba(255,255,255,.92) 0 3px, transparent 4px),
        radial-gradient(circle at 68% 18%, rgba(255,255,255,.78) 0 3px, transparent 4px),
        radial-gradient(circle at 82% 68%, rgba(255,255,255,.72) 0 3px, transparent 4px),
        radial-gradient(circle at 28% 78%, rgba(255,255,255,.76) 0 3px, transparent 4px),
        linear-gradient(145deg, transparent 18%, rgba(255,255,255,.18) 18.3%, transparent 19%),
        linear-gradient(30deg, transparent 28%, rgba(255,255,255,.16) 28.3%, transparent 29%);
    opacity: .85;
}

.float-card {
    position: absolute;
    z-index: 3;
    padding: 10px 14px;
    border-radius: 16px;
    background: rgba(255, 255, 255, .94);
    color: #23304A;
    box-shadow: 0 16px 40px rgba(25, 39, 83, .18);
    font-weight: 800;
    font-size: 13px;
}

.float-card.one { left: 4%; top: 12%; }
.float-card.two { right: 4%; top: 20%; }
.float-card.three { right: 2%; bottom: 22%; }
.float-card.four { left: 6%; bottom: 14%; }

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

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

.node-card {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: var(--radius-md);
    padding: 22px;
    box-shadow: var(--shadow);
}

.node-card h3 {
    margin-top: 12px;
}

.node-card p {
    font-size: 15px;
}

.split-section,
.global-layout,
.speed-layout,
.privacy-layout,
.multi-layout,
.protocol-layout,
.about-grid {
    display: grid;
    gap: 28px;
    align-items: center;
}

.visual-card {
    border-radius: var(--radius-lg);
    border: 1px solid var(--line);
    padding: 18px;
    background: #fff;
    box-shadow: var(--shadow);
}

.visual-card img {
    border-radius: 22px;
}

.feature-list,
.clean-list {
    margin: 20px 0 0;
    padding: 0;
    list-style: none;
    display: grid;
    gap: 10px;
}

.feature-list li,
.clean-list li {
    position: relative;
    padding-left: 26px;
    color: #3C465A;
}

.feature-list li::before,
.clean-list li::before {
    content: "";
    position: absolute;
    left: 0;
    top: 11px;
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: #2980FE;
}

.global-nodes-section {
    background:
        radial-gradient(circle at 12% 18%, rgba(41, 128, 254, .14), transparent 28%),
        radial-gradient(circle at 86% 72%, rgba(123, 78, 241, .13), transparent 30%),
        #F6F8FC;
}

.map-panel {
    position: relative;
    min-height: 360px;
    border-radius: var(--radius-lg);
    background:
        linear-gradient(120deg, rgba(53,88,242,.12), rgba(184,77,218,.10)),
        #FFFFFF;
    border: 1px solid var(--line);
    overflow: hidden;
    padding: 20px;
    box-shadow: var(--shadow);
}

.map-panel::before {
    content: "";
    position: absolute;
    inset: 18px;
    border-radius: 24px;
    background:
        radial-gradient(circle at 20% 40%, #2980FE 0 5px, transparent 6px),
        radial-gradient(circle at 48% 20%, #7B4EF1 0 5px, transparent 6px),
        radial-gradient(circle at 78% 50%, #B84DDA 0 5px, transparent 6px),
        radial-gradient(circle at 36% 72%, #2980FE 0 5px, transparent 6px),
        linear-gradient(30deg, transparent 40%, rgba(41,128,254,.18) 40.3%, transparent 41%),
        linear-gradient(145deg, transparent 36%, rgba(123,78,241,.18) 36.3%, transparent 37%);
    opacity: .8;
}

.map-panel img {
    position: relative;
    z-index: 1;
    width: 84%;
    margin: 38px auto 0;
    border-radius: 24px;
}

.speed-card,
.privacy-panel,
.protocol-panel,
.safety-panel,
.page-panel {
    border: 1px solid var(--line);
    border-radius: var(--radius-lg);
    background: #fff;
    padding: 24px;
    box-shadow: var(--shadow);
}

.speed-lines {
    display: grid;
    gap: 14px;
    margin-top: 22px;
}

.speed-line {
    display: grid;
    gap: 7px;
}

.speed-line span {
    display: flex;
    justify-content: space-between;
    color: #344054;
    font-weight: 700;
    font-size: 14px;
}

.speed-line i {
    height: 9px;
    border-radius: 999px;
    background: linear-gradient(90deg, #2980FE, #7B4EF1);
}

.privacy-tags,
.protocol-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: 18px;
}

.privacy-tags span,
.protocol-tags span {
    padding: 9px 12px;
    border-radius: 999px;
    background: #F1F5FB;
    color: #344054;
    font-weight: 750;
    font-size: 14px;
}

.no-log-cards,
.device-cards,
.protocol-cards,
.faq-grid,
.risk-grid,
.page-card-grid {
    display: grid;
    gap: 16px;
}

.info-card,
.device-card,
.protocol-card,
.risk-card,
.faq-item,
.page-card {
    border: 1px solid var(--line);
    border-radius: var(--radius-md);
    background: #fff;
    padding: 22px;
}

.risk-card {
    border-left: 4px solid #2980FE;
}

.info-card p,
.device-card p,
.protocol-card p,
.risk-card p,
.faq-item p,
.page-card p {
    font-size: 15px;
}

.process-steps {
    display: grid;
    gap: 14px;
    margin-top: 26px;
}

.step-card {
    position: relative;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: var(--radius-md);
    padding: 22px;
    box-shadow: 0 12px 30px rgba(33, 49, 86, .06);
}

.step-number {
    width: 38px;
    height: 38px;
    border-radius: 14px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    background: var(--gradient);
    font-weight: 900;
    margin-bottom: 12px;
}

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

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

.cta-section p {
    max-width: 680px;
    margin-left: auto;
    margin-right: auto;
    color: rgba(255, 255, 255, .86);
}

.cta-section .download-btn {
    margin-top: 26px;
}

.page-hero {
    padding: 58px 0 36px;
    background:
        radial-gradient(circle at 90% 10%, rgba(123,78,241,.12), transparent 34%),
        linear-gradient(180deg, #F6F9FF 0%, #FFFFFF 100%);
}

.page-hero .container {
    max-width: 920px;
}

.page-hero h1 {
    margin-top: 14px;
    font-size: clamp(32px, 7vw, 52px);
}

.page-hero p {
    font-size: 17px;
}

.content-shell {
    width: min(980px, calc(100% - 32px));
    margin: 0 auto;
    padding: 48px 0 70px;
}

.article-grid {
    display: grid;
    gap: 22px;
}

.article-body {
    display: grid;
    gap: 22px;
}

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

.aside-box {
    border-radius: var(--radius-md);
    background: #F6F8FC;
    border: 1px solid var(--line);
    padding: 22px;
}

.notice-box {
    border-radius: 20px;
    background: #EEF5FF;
    border: 1px solid #D7E7FF;
    padding: 18px;
    color: #344054;
}

.page-cta {
    margin-top: 24px;
    border-radius: var(--radius-lg);
    padding: 28px;
    background: #F7FAFF;
    border: 1px solid var(--line);
}

.download-center {
    text-align: center;
    max-width: 900px;
}

.install-steps {
    counter-reset: item;
    display: grid;
    gap: 14px;
    margin-top: 28px;
}

.install-step {
    display: flex;
    gap: 14px;
    text-align: left;
    padding: 18px;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 18px;
}

.install-step::before {
    counter-increment: item;
    content: counter(item);
    flex: 0 0 34px;
    width: 34px;
    height: 34px;
    border-radius: 12px;
    background: #2980FE;
    color: #fff;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-weight: 900;
}

.site-footer {
    background: #111827;
    color: #D8DEE9;
    padding: 50px 0 24px;
}

.site-footer p,
.site-footer a,
.footer-bottom {
    color: #AEB8C8;
}

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

.footer-grid h3 {
    color: #fff;
    font-size: 17px;
    margin-bottom: 12px;
}

.footer-grid a {
    display: block;
    padding: 5px 0;
}

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

.footer-brand {
    display: flex;
    align-items: center;
    gap: 10px;
    color: #fff;
    font-size: 19px;
}

.footer-brand img {
    width: 40px;
    height: 40px;
    border-radius: 13px;
    object-fit: cover;
}

.footer-bottom {
    margin-top: 34px;
    padding-top: 20px;
    border-top: 1px solid rgba(255, 255, 255, .12);
    display: flex;
    flex-direction: column;
    gap: 8px;
    font-size: 14px;
}

@media (min-width: 680px) {
    .node-grid,
    .no-log-cards,
    .device-cards,
    .protocol-cards,
    .risk-grid,
    .faq-grid,
    .page-card-grid,
    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
    }

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

@media (min-width: 960px) {
    .nav-toggle {
        display: none;
    }

    .site-nav {
        position: static;
        display: flex;
        flex-direction: row;
        align-items: center;
        box-shadow: none;
        border: 0;
        padding: 0;
        background: transparent;
        gap: 2px;
    }

    .site-nav a {
        font-size: 14px;
        padding: 9px 10px;
    }

    .hero-grid,
    .split-section,
    .global-layout,
    .speed-layout,
    .privacy-layout,
    .multi-layout,
    .protocol-layout,
    .about-grid,
    .article-grid {
        grid-template-columns: 1.02fr .98fr;
    }

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

    .no-log-cards,
    .device-cards,
    .protocol-cards,
    .risk-grid {
        grid-template-columns: repeat(3, 1fr);
    }

    .process-steps {
        grid-template-columns: repeat(3, 1fr);
    }

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

    .footer-bottom {
        flex-direction: row;
        justify-content: space-between;
    }

    .article-grid {
        align-items: start;
    }

    .aside-box {
        position: sticky;
        top: 96px;
    }
}

@media (min-width: 1180px) {
    .site-nav a {
        padding: 9px 12px;
    }
}

@media (max-width: 520px) {
    .section {
        padding: 46px 0;
    }

    .vpn-network-hero {
        padding-top: 50px;
        min-height: auto;
    }

    .hero-visual {
        min-height: 320px;
        padding: 8px 0 20px;
    }

    .float-card {
        font-size: 12px;
        padding: 8px 10px;
    }

    .download-btn {
        width: 100%;
        min-height: 52px;
    }

    .hero-actions .download-btn,
    .cta-section .download-btn,
    .page-cta .download-btn {
        width: 100%;
    }
}