* {
    box-sizing: border-box;
}

:root {
    --gradient: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    --blue: #2980FE;
    --blue-dark: #1768E8;
    --text: #202638;
    --muted: #677085;
    --light: #F5F7FB;
    --line: #E5EAF3;
    --white: #FFFFFF;
    --shadow: 0 18px 48px rgba(30, 54, 103, 0.10);
    --radius: 24px;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", "PingFang SC", Arial, sans-serif;
    color: var(--text);
    background: #ffffff;
    line-height: 1.75;
    overflow-x: hidden;
}

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

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

p {
    margin: 0 0 14px;
}

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

.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, 0.9);
}

.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;
}

.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 22px rgba(41, 128, 254, 0.18);
}

.site-nav {
    display: none;
    flex-direction: column;
    position: absolute;
    left: 16px;
    right: 16px;
    top: 72px;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 22px;
    box-shadow: var(--shadow);
    padding: 14px;
}

.site-nav a {
    padding: 12px 14px;
    color: #3c465a;
    border-radius: 14px;
    font-weight: 600;
}

.site-nav a:hover {
    background: #F2F6FF;
    color: var(--blue);
}

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

.nav-toggle-label {
    width: 44px;
    height: 44px;
    border: 1px solid var(--line);
    border-radius: 14px;
    display: grid;
    place-content: center;
    gap: 5px;
    cursor: pointer;
}

.nav-toggle-label span {
    width: 20px;
    height: 2px;
    background: #25324a;
    display: block;
    border-radius: 4px;
}

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

.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 0 28px;
    border-radius: 999px;
    background: var(--blue);
    color: #ffffff;
    font-weight: 800;
    letter-spacing: 0.02em;
    box-shadow: 0 12px 26px rgba(41, 128, 254, 0.28);
    transition: transform 0.2s ease, background 0.2s ease, box-shadow 0.2s ease;
}

.download-btn:hover {
    background: var(--blue-dark);
    transform: translateY(-2px);
    box-shadow: 0 14px 32px rgba(23, 104, 232, 0.3);
}

.hero, .vpn-network-hero {
    background: var(--gradient);
    color: #ffffff;
    position: relative;
    overflow: hidden;
}

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

.vpn-network-hero::before {
    width: 420px;
    height: 420px;
    background: rgba(255, 255, 255, 0.12);
    top: -120px;
    right: -120px;
}

.vpn-network-hero::after {
    width: 260px;
    height: 260px;
    background: rgba(255, 255, 255, 0.11);
    bottom: -70px;
    left: -80px;
}

.hero-inner {
    position: relative;
    z-index: 2;
    width: min(1160px, calc(100% - 32px));
    margin: 0 auto;
    padding: 72px 0 48px;
    display: grid;
    gap: 34px;
    align-items: center;
}

.hero h1 {
    font-size: clamp(2.2rem, 9vw, 4.4rem);
    line-height: 1.1;
    margin: 0 0 18px;
    letter-spacing: -0.04em;
}

.hero .lead {
    font-size: 1.05rem;
    color: rgba(255, 255, 255, 0.86);
    max-width: 680px;
}

.hero-tags,
.float-tags,
.badge-row {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin: 22px 0;
}

.hero-tags span,
.float-tags span,
.badge,
.category-badge {
    border-radius: 999px;
    padding: 7px 12px;
    font-size: 0.86rem;
    font-weight: 700;
}

.hero-tags span,
.float-tags span {
    color: #fff;
    background: rgba(255, 255, 255, 0.16);
    border: 1px solid rgba(255, 255, 255, 0.26);
}

.hero-visual {
    position: relative;
    min-height: 320px;
    display: grid;
    place-items: center;
}

.visual-card {
    width: min(430px, 92%);
    padding: 18px;
    border-radius: 30px;
    background: rgba(255, 255, 255, 0.16);
    border: 1px solid rgba(255, 255, 255, 0.24);
    box-shadow: 0 28px 72px rgba(13, 24, 69, 0.24);
    backdrop-filter: blur(14px);
}

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

.float-tags {
    justify-content: center;
}

.node-line {
    position: absolute;
    inset: 18px;
    background:
        radial-gradient(circle at 18% 28%, rgba(255,255,255,.9) 0 3px, transparent 4px),
        radial-gradient(circle at 78% 22%, rgba(255,255,255,.8) 0 3px, transparent 4px),
        radial-gradient(circle at 62% 72%, rgba(255,255,255,.76) 0 3px, transparent 4px),
        linear-gradient(135deg, transparent 24%, rgba(255,255,255,.25) 25%, transparent 26%),
        linear-gradient(35deg, transparent 54%, rgba(255,255,255,.22) 55%, transparent 56%);
    opacity: .55;
}

.section {
    padding: 64px 0;
}

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

.section-head {
    max-width: 760px;
    margin-bottom: 30px;
}

.section-head.center {
    text-align: center;
    margin-left: auto;
    margin-right: auto;
}

.section-kicker,
.category-badge {
    display: inline-flex;
    align-items: center;
    background: #EDF4FF;
    color: var(--blue);
    border: 1px solid #D8E8FF;
    margin-bottom: 12px;
}

.section h2,
.section-title,
.page-hero h1 {
    margin: 0 0 12px;
    line-height: 1.22;
    color: #172033;
}

.section h2,
.section-title {
    font-size: clamp(1.7rem, 5vw, 2.55rem);
}

.section-head p,
.card p,
.feature-list li,
.page-summary,
.page-content p,
.faq-item p,
.risk-card p,
.step-card p {
    color: var(--muted);
}

.node-overview {
    margin-top: -34px;
    position: relative;
    z-index: 3;
}

.node-overview-grid,
.card-grid,
.risk-grid,
.faq-grid,
.related-grid {
    display: grid;
    gap: 18px;
}

.node-card,
.card,
.risk-card,
.faq-item,
.step-card,
.panel,
.info-box {
    background: var(--white);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    box-shadow: 0 12px 34px rgba(24, 42, 78, 0.06);
}

.node-card,
.card,
.risk-card,
.faq-item,
.step-card {
    padding: 22px;
}

.node-card .label,
.card .label {
    color: var(--blue);
    font-size: .82rem;
    font-weight: 800;
    margin-bottom: 8px;
    display: inline-flex;
}

.node-card h3,
.card h3,
.risk-card h3,
.step-card h3,
.faq-item h3 {
    margin: 0 0 8px;
    color: #1e293b;
}

.text-link {
    display: inline-flex;
    margin-top: 10px;
    color: var(--blue);
    font-weight: 800;
}

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

.media-frame {
    border-radius: 32px;
    padding: 16px;
    background: #ffffff;
    border: 1px solid var(--line);
    box-shadow: var(--shadow);
}

.media-frame img {
    border-radius: 24px;
    margin: auto;
}

.bullet-grid {
    display: grid;
    gap: 12px;
    margin: 20px 0;
}

.bullet {
    padding: 14px 16px;
    border-radius: 18px;
    background: #F7FAFF;
    border: 1px solid #E6EEF8;
    color: #3b465c;
}

.global-map-panel {
    position: relative;
    overflow: hidden;
    background:
        radial-gradient(circle at 18% 22%, rgba(41,128,254,.18) 0 8px, transparent 9px),
        radial-gradient(circle at 78% 32%, rgba(123,78,241,.16) 0 9px, transparent 10px),
        radial-gradient(circle at 56% 72%, rgba(184,77,218,.14) 0 8px, transparent 9px),
        linear-gradient(135deg, #F6F9FF 0%, #FFFFFF 100%);
}

.global-map-panel::before {
    content: "";
    position: absolute;
    inset: 18px;
    border-radius: 28px;
    background:
        linear-gradient(28deg, transparent 20%, rgba(41,128,254,.18) 21%, transparent 22%),
        linear-gradient(145deg, transparent 32%, rgba(123,78,241,.16) 33%, transparent 34%),
        linear-gradient(70deg, transparent 48%, rgba(184,77,218,.15) 49%, transparent 50%);
}

.global-map-panel img,
.global-map-panel .map-content {
    position: relative;
    z-index: 2;
}

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

.speed-card {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 22px;
    padding: 18px;
}

.speed-line {
    height: 8px;
    border-radius: 999px;
    background: linear-gradient(90deg, #D9E8FF, #2980FE);
    margin: 12px 0;
}

.privacy-panel,
.protocol-panel {
    padding: 24px;
    border-radius: 30px;
    background: linear-gradient(145deg, #FFFFFF 0%, #F3F7FF 100%);
    border: 1px solid var(--line);
    box-shadow: var(--shadow);
}

.privacy-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin: 16px 0;
}

.privacy-tags span {
    padding: 8px 12px;
    border-radius: 999px;
    background: #EDF4FF;
    color: #1768E8;
    font-weight: 700;
    font-size: .88rem;
}

.no-log-policy-section .card {
    border-top: 4px solid var(--blue);
}

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

.device-card {
    padding: 16px;
    border-radius: 20px;
    background: #F7FAFF;
    border: 1px solid #E4ECFA;
}

.protocol-stack {
    display: grid;
    gap: 12px;
}

.protocol-item {
    display: grid;
    grid-template-columns: 42px 1fr;
    gap: 12px;
    align-items: start;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 20px;
    padding: 15px;
}

.protocol-num,
.step-num {
    width: 42px;
    height: 42px;
    border-radius: 14px;
    background: var(--blue);
    color: #fff;
    font-weight: 900;
    display: grid;
    place-items: center;
}

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

.step-card {
    display: grid;
    grid-template-columns: 46px 1fr;
    gap: 14px;
}

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

.cta-section {
    position: relative;
    overflow: hidden;
    background: var(--gradient);
    color: #fff;
    padding: 58px 0;
    text-align: center;
}

.cta-section::before {
    width: 300px;
    height: 300px;
    background: rgba(255,255,255,.13);
    top: -90px;
    left: -80px;
}

.cta-inner {
    position: relative;
    z-index: 2;
    width: min(760px, calc(100% - 32px));
    margin: 0 auto;
}

.cta-section h2 {
    color: #fff;
    font-size: clamp(1.8rem, 6vw, 3rem);
    margin: 0 0 14px;
}

.cta-section p {
    color: rgba(255,255,255,.86);
}

.page-hero {
    background: linear-gradient(135deg, #F5F8FF 0%, #FFFFFF 100%);
    padding: 54px 0 34px;
    border-bottom: 1px solid var(--line);
}

.page-hero h1 {
    font-size: clamp(2rem, 7vw, 3.5rem);
}

.page-summary {
    max-width: 820px;
    font-size: 1.04rem;
}

.page-layout {
    display: grid;
    gap: 24px;
    align-items: start;
}

.page-content {
    display: grid;
    gap: 22px;
}

.article-card,
.side-card {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 24px;
    padding: 24px;
    box-shadow: 0 10px 28px rgba(28, 46, 82, .055);
}

.article-card h2,
.side-card h2 {
    margin-top: 0;
    line-height: 1.28;
}

.check-list,
.clean-list {
    padding: 0;
    margin: 14px 0 0;
    list-style: none;
    display: grid;
    gap: 10px;
}

.check-list li,
.clean-list li {
    padding: 12px 14px;
    background: #F7FAFF;
    border: 1px solid #E5EEFC;
    border-radius: 16px;
    color: #4a566b;
}

.side-card {
    position: sticky;
    top: 92px;
}

.side-card a {
    color: var(--blue);
    font-weight: 800;
    display: block;
    margin: 8px 0;
}

.download-center {
    text-align: center;
    max-width: 860px;
    margin: 0 auto;
}

.download-steps {
    counter-reset: step;
    display: grid;
    gap: 14px;
    margin-top: 24px;
}

.download-step {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 20px;
    padding: 18px;
    text-align: left;
}

.site-footer {
    background: #111827;
    color: rgba(255,255,255,.76);
    padding-top: 48px;
}

.footer-grid {
    display: grid;
    gap: 24px;
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: 10px;
    color: #fff;
    margin-bottom: 12px;
}

.footer-brand img {
    width: 40px;
    height: 40px;
    border-radius: 12px;
    object-fit: cover;
}

.site-footer h3 {
    margin: 0 0 12px;
    color: #fff;
}

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

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

.footer-bottom {
    margin-top: 34px;
    padding: 18px;
    border-top: 1px solid rgba(255,255,255,.12);
    text-align: center;
    color: rgba(255,255,255,.6);
    font-size: .92rem;
}

@media (min-width: 680px) {
    .node-overview-grid,
    .card-grid,
    .risk-grid,
    .faq-grid,
    .related-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

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

    .footer-grid {
        grid-template-columns: 1.5fr repeat(3, 1fr);
    }
}

@media (min-width: 920px) {
    .nav-toggle-label {
        display: none;
    }

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

    .site-nav a {
        padding: 10px 12px;
        font-size: .96rem;
    }

    .hero-inner {
        grid-template-columns: 1.05fr .95fr;
        padding: 94px 0 70px;
    }

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

    .split,
    .vpn-connection-section,
    .global-nodes-section,
    .high-speed-section,
    .privacy-protection-section,
    .multi-device-section,
    .encryption-protocol-section,
    .page-layout {
        grid-template-columns: 1fr 1fr;
    }

    .page-layout {
        grid-template-columns: minmax(0, 1fr) 320px;
    }

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

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

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

    .section {
        padding: 82px 0;
    }
}

@media (min-width: 1100px) {
    .site-nav a {
        padding: 10px 14px;
    }
}

@media (max-width: 420px) {
    .container,
    .hero-inner,
    .cta-inner {
        width: min(100% - 24px, 1120px);
    }

    .node-card,
    .card,
    .risk-card,
    .faq-item,
    .step-card,
    .article-card,
    .side-card {
        padding: 18px;
        border-radius: 20px;
    }

    .download-btn {
        width: 100%;
    }
}