* {
    box-sizing: border-box;
}

:root {
    --gradient: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    --blue: #2980FE;
    --blue-dark: #1768E8;
    --text: #202635;
    --muted: #626B7A;
    --line: #E6EAF2;
    --light: #F6F8FC;
    --soft-blue: #F1F6FF;
    --white: #FFFFFF;
    --radius: 24px;
    --shadow: 0 18px 45px rgba(31, 55, 96, .10);
}

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
    color: var(--text);
    background: #fff;
    line-height: 1.75;
    font-size: 16px;
    overflow-x: hidden;
}

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

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

p {
    margin: 0 0 16px;
    color: var(--muted);
}

h1, h2, h3 {
    color: var(--text);
    line-height: 1.22;
    margin: 0 0 16px;
}

h1 {
    font-size: clamp(34px, 8vw, 64px);
    letter-spacing: -1.4px;
}

h2 {
    font-size: clamp(26px, 5vw, 42px);
    letter-spacing: -0.6px;
}

h3 {
    font-size: 20px;
}

.site-header {
    position: sticky;
    top: 0;
    z-index: 50;
    background: rgba(255,255,255,.92);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid rgba(230,234,242,.8);
}

.header-inner,
.content-container,
.footer-inner,
.footer-bottom {
    width: min(1160px, calc(100% - 32px));
    margin: 0 auto;
}

.header-inner {
    min-height: 68px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-weight: 800;
    color: #172033;
    letter-spacing: -.2px;
    white-space: nowrap;
}

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

.site-nav {
    display: none;
    position: absolute;
    left: 16px;
    right: 16px;
    top: 76px;
    padding: 12px;
    border: 1px solid var(--line);
    border-radius: 20px;
    background: #fff;
    box-shadow: var(--shadow);
}

.site-nav.is-open {
    display: grid;
    gap: 6px;
}

.site-nav a {
    padding: 10px 12px;
    border-radius: 14px;
    color: #415066;
    font-weight: 700;
    font-size: 14px;
}

.site-nav a:hover,
.site-nav a.active {
    color: var(--blue);
    background: #EFF5FF;
}

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

.nav-toggle span {
    width: 18px;
    height: 2px;
    background: #172033;
    border-radius: 99px;
}

.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 50px;
    padding: 13px 26px;
    background: var(--blue);
    color: #fff;
    border-radius: 999px;
    font-weight: 800;
    box-shadow: 0 14px 26px rgba(41,128,254,.25);
    transition: transform .2s ease, background .2s ease, box-shadow .2s ease;
}

.download-btn:hover {
    background: var(--blue-dark);
    transform: translateY(-2px);
    box-shadow: 0 18px 32px rgba(23,104,232,.28);
}

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

.text-link::after {
    content: "›";
    margin-left: 6px;
    font-size: 20px;
    line-height: 1;
}

.section {
    padding: 72px 0;
}

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

.section-head {
    margin-bottom: 28px;
    max-width: 760px;
}

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

.eyebrow,
.badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 7px 12px;
    border-radius: 999px;
    background: #EFF5FF;
    color: var(--blue);
    font-size: 13px;
    font-weight: 800;
    margin-bottom: 16px;
}

.vpn-network-hero {
    position: relative;
    overflow: hidden;
    background: var(--gradient);
    color: #fff;
    padding: 72px 0 84px;
}

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

.vpn-network-hero::before {
    width: 520px;
    height: 520px;
    right: -220px;
    top: -220px;
    background: rgba(255,255,255,.18);
}

.vpn-network-hero::after {
    left: 0;
    right: 0;
    bottom: 0;
    height: 160px;
    background-image: radial-gradient(circle, rgba(255,255,255,.55) 1px, transparent 1.5px), linear-gradient(120deg, rgba(255,255,255,.18), transparent 40%);
    background-size: 38px 38px, 100% 100%;
    opacity: .55;
}

.hero-grid {
    position: relative;
    z-index: 1;
    width: min(1160px, calc(100% - 32px));
    margin: 0 auto;
    display: grid;
    gap: 42px;
    align-items: center;
}

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

.hero-copy p {
    font-size: 18px;
    max-width: 680px;
    opacity: .92;
}

.hero-actions {
    display: flex;
    align-items: center;
    gap: 16px;
    flex-wrap: wrap;
    margin-top: 24px;
}

.hero-note {
    color: rgba(255,255,255,.85);
    font-size: 14px;
}

.hero-tags,
.floating-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: 26px;
}

.hero-tags span,
.floating-tags span {
    border: 1px solid rgba(255,255,255,.35);
    background: rgba(255,255,255,.14);
    color: #fff;
    padding: 8px 12px;
    border-radius: 999px;
    font-weight: 700;
    font-size: 13px;
}

.hero-visual {
    position: relative;
    min-height: 280px;
}

.hero-device-card {
    position: relative;
    z-index: 1;
    padding: 18px;
    border-radius: 32px;
    background: rgba(255,255,255,.18);
    border: 1px solid rgba(255,255,255,.32);
    box-shadow: 0 30px 80px rgba(20,34,88,.28);
    backdrop-filter: blur(14px);
}

.hero-device-card img {
    border-radius: 24px;
    margin: 0 auto;
}

.status-card {
    position: absolute;
    z-index: 2;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 14px;
    border-radius: 16px;
    background: rgba(255,255,255,.95);
    color: #23314A;
    box-shadow: 0 14px 36px rgba(31,55,96,.16);
    font-size: 13px;
    font-weight: 800;
}

.status-card::before,
.node-dot::before {
    content: "";
    width: 8px;
    height: 8px;
    background: var(--blue);
    border-radius: 999px;
    box-shadow: 0 0 0 5px rgba(41,128,254,.16);
}

.status-1 { left: 4px; top: 20px; }
.status-2 { right: 4px; top: 72px; }
.status-3 { left: 18px; bottom: 38px; }
.status-4 { right: 16px; bottom: 94px; }

.node-overview {
    margin-top: -46px;
    position: relative;
    z-index: 5;
}

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

.node-card,
.feature-card,
.policy-card,
.risk-card,
.faq-item,
.info-card,
.step-card,
.tip-card,
.side-panel,
.download-panel,
.security-panel {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 24px;
    box-shadow: 0 12px 36px rgba(31,55,96,.06);
}

.node-card .tag {
    display: inline-flex;
    padding: 5px 10px;
    margin-bottom: 14px;
    border-radius: 999px;
    background: #EFF5FF;
    color: var(--blue);
    font-size: 12px;
    font-weight: 800;
}

.split-section {
    display: grid;
    gap: 28px;
    align-items: center;
}

.vpn-connection-section .image-frame,
.high-speed-section .image-frame,
.multi-device-section .image-frame,
.protocol-visual,
.privacy-visual {
    background: linear-gradient(180deg, #F7FAFF, #FFFFFF);
    border: 1px solid var(--line);
    border-radius: 32px;
    padding: 20px;
    box-shadow: var(--shadow);
}

.bullet-list,
.check-list {
    list-style: none;
    padding: 0;
    margin: 18px 0;
    display: grid;
    gap: 12px;
}

.bullet-list li,
.check-list li {
    position: relative;
    padding-left: 28px;
    color: #3D4858;
}

.bullet-list li::before,
.check-list li::before {
    content: "";
    position: absolute;
    left: 0;
    top: 11px;
    width: 9px;
    height: 9px;
    border-radius: 99px;
    background: var(--blue);
    box-shadow: 0 0 0 5px #EAF3FF;
}

.global-nodes-section {
    background: var(--gradient);
    color: #fff;
    position: relative;
    overflow: hidden;
}

.global-nodes-section::before {
    content: "";
    position: absolute;
    inset: 0;
    background-image: radial-gradient(circle, rgba(255,255,255,.5) 1px, transparent 1.5px), linear-gradient(135deg, rgba(255,255,255,.18), transparent 45%);
    background-size: 42px 42px, 100% 100%;
    opacity: .5;
}

.global-nodes-section .content-container {
    position: relative;
    z-index: 1;
}

.global-nodes-section h2,
.global-nodes-section p,
.global-nodes-section .bullet-list li {
    color: #fff;
}

.global-nodes-section .bullet-list li::before {
    background: #fff;
    box-shadow: 0 0 0 5px rgba(255,255,255,.18);
}

.node-map-card {
    border-radius: 32px;
    background: rgba(255,255,255,.16);
    border: 1px solid rgba(255,255,255,.28);
    padding: 20px;
    backdrop-filter: blur(12px);
}

.node-map-card img {
    border-radius: 24px;
}

.node-lines {
    margin-top: 16px;
    display: grid;
    gap: 10px;
}

.node-dot {
    display: flex;
    align-items: center;
    gap: 10px;
    color: #fff;
    font-weight: 700;
}

.speed-lines {
    display: grid;
    gap: 12px;
    margin-top: 18px;
}

.speed-line {
    padding: 16px;
    border: 1px solid var(--line);
    border-radius: 18px;
    background: #fff;
}

.speed-line span {
    display: block;
    height: 8px;
    border-radius: 99px;
    background: linear-gradient(90deg, #CFE3FF, #2980FE);
    margin-top: 10px;
}

.privacy-protection-section .security-panel {
    background: linear-gradient(180deg, #FFFFFF, #F5F9FF);
}

.security-panel .security-row {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    padding: 14px 0;
    border-bottom: 1px solid var(--line);
}

.security-panel .security-row:last-child {
    border-bottom: 0;
}

.security-icon {
    width: 32px;
    height: 32px;
    border-radius: 12px;
    display: grid;
    place-items: center;
    background: #EFF5FF;
    color: var(--blue);
    font-weight: 900;
    flex: 0 0 auto;
}

.policy-grid .policy-card {
    border-top: 4px solid var(--blue);
}

.device-grid {
    display: grid;
    gap: 16px;
    margin-top: 18px;
}

.device-pill {
    padding: 16px 18px;
    border-radius: 18px;
    border: 1px solid var(--line);
    background: #fff;
    font-weight: 800;
    color: #23314A;
}

.protocol-panel {
    border-radius: 32px;
    border: 1px solid var(--line);
    background: #fff;
    box-shadow: var(--shadow);
    overflow: hidden;
}

.protocol-row {
    display: grid;
    gap: 8px;
    padding: 20px;
    border-bottom: 1px solid var(--line);
}

.protocol-row:last-child {
    border-bottom: 0;
}

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

.step-card {
    position: relative;
}

.step-number {
    width: 40px;
    height: 40px;
    border-radius: 16px;
    display: grid;
    place-items: center;
    background: var(--blue);
    color: #fff;
    font-weight: 900;
    margin-bottom: 14px;
}

.risk-card {
    border-left: 5px solid var(--blue);
}

.risk-card strong {
    display: block;
    margin-top: 8px;
    color: #2C394D;
}

.faq-item h3 {
    font-size: 18px;
}

.cta-section {
    padding: 72px 0;
    background: var(--gradient);
}

.cta-card {
    width: min(900px, calc(100% - 32px));
    margin: 0 auto;
    text-align: center;
    color: #fff;
}

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

.page-hero {
    background: linear-gradient(180deg, #F3F7FF, #FFFFFF);
    padding: 64px 0 40px;
}

.page-hero-inner {
    width: min(960px, calc(100% - 32px));
    margin: 0 auto;
}

.page-hero p {
    font-size: 18px;
}

.article-layout {
    width: min(1120px, calc(100% - 32px));
    margin: 0 auto;
    display: grid;
    gap: 24px;
    padding: 54px 0 76px;
}

.article-main,
.article-aside {
    display: grid;
    gap: 20px;
}

.article-main .info-card h2 {
    font-size: 26px;
}

.notice-box {
    border-radius: 24px;
    padding: 22px;
    background: #F4F8FF;
    border: 1px solid #DDEBFF;
}

.download-page {
    min-height: 520px;
}

.download-panel {
    text-align: center;
}

.download-panel .download-btn {
    margin: 10px 0 22px;
}

.steps-list {
    list-style: none;
    padding: 0;
    margin: 0;
    display: grid;
    gap: 12px;
    counter-reset: ordered;
}

.steps-list li {
    counter-increment: ordered;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 18px;
    padding: 16px 16px 16px 58px;
    position: relative;
}

.steps-list li::before {
    content: counter(ordered);
    position: absolute;
    left: 16px;
    top: 15px;
    width: 30px;
    height: 30px;
    border-radius: 12px;
    display: grid;
    place-items: center;
    background: var(--blue);
    color: #fff;
    font-weight: 900;
}

.site-footer {
    background: #101827;
    color: #D6DDEB;
    padding-top: 54px;
}

.site-footer p,
.site-footer a {
    color: #AEB9CC;
}

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

.footer-logo span,
.site-footer h3 {
    color: #fff;
}

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

.footer-links div {
    display: grid;
    gap: 8px;
}

.footer-bottom {
    border-top: 1px solid rgba(255,255,255,.1);
    margin-top: 36px;
    padding: 20px 0;
}

.footer-bottom p {
    margin: 0;
    font-size: 14px;
}

@media (min-width: 700px) {
    .node-overview-grid,
    .feature-grid,
    .policy-grid,
    .risk-grid,
    .faq-grid,
    .card-grid,
    .device-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

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

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

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

    .site-nav a {
        padding: 8px 10px;
    }

    .hero-grid,
    .split-section {
        grid-template-columns: minmax(0, 1.02fr) minmax(360px, .98fr);
    }

    .reverse-on-desktop {
        grid-template-columns: minmax(360px, .96fr) minmax(0, 1.04fr);
    }

    .reverse-on-desktop .split-copy {
        order: 2;
    }

    .reverse-on-desktop .split-media {
        order: 1;
    }

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

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

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

    .article-layout {
        grid-template-columns: minmax(0, 1fr) 320px;
        align-items: start;
    }

    .footer-inner {
        grid-template-columns: 1.1fr 1.6fr;
    }

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

@media (max-width: 480px) {
    .header-inner,
    .content-container,
    .footer-inner,
    .footer-bottom,
    .hero-grid,
    .article-layout,
    .page-hero-inner {
        width: min(100% - 24px, 1160px);
    }

    .section {
        padding: 54px 0;
    }

    .vpn-network-hero {
        padding: 52px 0 72px;
    }

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

    .hero-actions {
        align-items: stretch;
    }

    .status-card {
        position: static;
        margin: 10px 6px 0 0;
    }

    .floating-tags {
        display: grid;
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .hero-visual {
        min-height: auto;
    }
}