* {
    box-sizing: border-box;
}

:root {
    --blue: #2980FE;
    --blue-dark: #1768E8;
    --purple-gradient: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    --text: #1f2937;
    --muted: #667085;
    --light: #f5f7fb;
    --line: #e5eaf3;
    --white: #ffffff;
    --deep: #101828;
    --shadow: 0 18px 45px rgba(31, 41, 55, 0.08);
    --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;
}

.site-header {
    position: sticky;
    top: 0;
    z-index: 30;
    background: rgba(255, 255, 255, 0.94);
    border-bottom: 1px solid rgba(229, 234, 243, 0.85);
    backdrop-filter: blur(16px);
}

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

.header-inner {
    min-height: 70px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
}

.brand,
.footer-brand {
    display: flex;
    align-items: center;
    gap: 12px;
}

.brand img,
.footer-brand img {
    width: 42px;
    height: 42px;
    border-radius: 13px;
    object-fit: cover;
}

.brand span {
    font-size: 18px;
    font-weight: 800;
    color: var(--deep);
}

.nav-toggle {
    width: 44px;
    height: 44px;
    border: 1px solid var(--line);
    border-radius: 14px;
    background: var(--white);
    color: var(--deep);
    font-size: 22px;
}

.site-nav {
    position: absolute;
    top: 70px;
    left: 16px;
    right: 16px;
    display: none;
    flex-direction: column;
    gap: 6px;
    padding: 14px;
    background: var(--white);
    border: 1px solid var(--line);
    border-radius: 18px;
    box-shadow: var(--shadow);
}

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

.site-nav a {
    padding: 10px 12px;
    border-radius: 12px;
    color: #344054;
    font-size: 15px;
    font-weight: 650;
}

.site-nav a:hover,
.site-nav a.active {
    background: #eef5ff;
    color: var(--blue);
}

.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 46px;
    padding: 12px 24px;
    border-radius: 999px;
    background: var(--blue);
    color: #fff;
    font-weight: 800;
    box-shadow: 0 14px 28px rgba(41, 128, 254, 0.24);
    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 18px 34px rgba(23, 104, 232, 0.28);
}

.section {
    padding: 64px 0;
}

.section-soft {
    background: linear-gradient(180deg, #f7f9ff 0%, #ffffff 100%);
}

.section-title {
    max-width: 760px;
    margin: 0 auto 28px;
    text-align: center;
}

.section-title .eyebrow,
.page-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 12px;
    padding: 6px 12px;
    border-radius: 999px;
    background: #edf5ff;
    color: var(--blue);
    font-size: 13px;
    font-weight: 800;
}

.section-title h2,
.page-hero h1,
.vpn-network-hero h1 {
    margin: 0;
    color: var(--deep);
    line-height: 1.18;
    letter-spacing: -0.02em;
}

.section-title h2 {
    font-size: clamp(28px, 4vw, 42px);
}

.section-title p,
.page-hero p,
.hero-copy p,
.card p,
.feature-copy p {
    color: var(--muted);
}

.vpn-network-hero {
    position: relative;
    padding: 76px 0 54px;
    overflow: hidden;
    color: #fff;
    background: var(--purple-gradient);
}

.vpn-network-hero::before,
.vpn-network-hero::after {
    content: "";
    position: absolute;
    inset: 0;
    pointer-events: none;
}

.vpn-network-hero::before {
    opacity: 0.22;
    background-image: radial-gradient(circle at 18% 22%, rgba(255,255,255,0.9) 0 2px, transparent 3px), radial-gradient(circle at 82% 36%, rgba(255,255,255,0.75) 0 2px, transparent 3px), radial-gradient(circle at 62% 78%, rgba(255,255,255,0.72) 0 2px, transparent 3px), linear-gradient(135deg, transparent 0 32%, rgba(255,255,255,0.18) 32.2% 32.5%, transparent 32.8% 100%);
    background-size: 220px 220px, 260px 260px, 300px 300px, 100% 100%;
}

.vpn-network-hero::after {
    background: radial-gradient(circle at 72% 16%, rgba(255,255,255,0.22), transparent 32%), radial-gradient(circle at 12% 86%, rgba(255,255,255,0.16), transparent 34%);
}

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

.hero-copy h1 {
    font-size: clamp(36px, 8vw, 68px);
    color: #fff;
}

.hero-copy p {
    max-width: 620px;
    margin: 18px 0 24px;
    color: rgba(255, 255, 255, 0.88);
    font-size: 17px;
}

.hero-tags,
.status-tags,
.tag-row {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: 18px;
}

.hero-tags span,
.status-tags span,
.tag-row span {
    display: inline-flex;
    align-items: center;
    padding: 7px 12px;
    border-radius: 999px;
    font-size: 13px;
    font-weight: 700;
}

.hero-tags span,
.status-tags span {
    background: rgba(255, 255, 255, 0.16);
    color: #fff;
    border: 1px solid rgba(255, 255, 255, 0.24);
}

.hero-visual {
    position: relative;
    min-height: 320px;
}

.hero-device {
    position: relative;
    width: min(450px, 100%);
    margin: 0 auto;
    padding: 18px;
    border-radius: 32px;
    background: rgba(255, 255, 255, 0.18);
    border: 1px solid rgba(255, 255, 255, 0.28);
    box-shadow: 0 24px 65px rgba(16, 24, 40, 0.28);
}

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

.float-card {
    position: absolute;
    display: none;
    padding: 12px 14px;
    background: rgba(255, 255, 255, 0.92);
    color: var(--deep);
    border-radius: 16px;
    box-shadow: var(--shadow);
    font-size: 13px;
    font-weight: 800;
}

.float-card small {
    display: block;
    color: var(--blue);
    font-weight: 800;
}

.float-one { top: 22px; left: 0; }
.float-two { top: 38%; right: 0; }
.float-three { bottom: 42px; left: 8%; }
.float-four { bottom: 8px; right: 10%; }

.node-overview {
    margin-top: -26px;
    position: relative;
    z-index: 2;
}

.node-grid,
.feature-grid,
.policy-grid,
.risk-grid,
.faq-grid,
.article-grid,
.cards-grid,
.process-steps {
    display: grid;
    grid-template-columns: 1fr;
    gap: 18px;
}

.node-card,
.card,
.risk-card,
.faq-item,
.step-card,
.article-card,
.tip-box {
    background: var(--white);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    box-shadow: 0 12px 30px rgba(16, 24, 40, 0.05);
}

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

.node-card .label,
.card .label {
    display: inline-block;
    margin-bottom: 10px;
    padding: 4px 10px;
    border-radius: 999px;
    background: #eef5ff;
    color: var(--blue);
    font-size: 12px;
    font-weight: 800;
}

.node-card h3,
.card h3,
.risk-card h3,
.step-card h3,
.article-card h3 {
    margin: 0 0 8px;
    color: var(--deep);
}

.text-link {
    display: inline-flex;
    margin-top: 12px;
    color: var(--blue);
    font-weight: 800;
}

.split-section,
.vpn-connection-section,
.high-speed-section,
.privacy-protection-section,
.multi-device-section,
.encryption-protocol-section {
    display: grid;
    grid-template-columns: 1fr;
    gap: 26px;
    align-items: center;
}

.feature-copy h2 {
    margin: 0 0 14px;
    color: var(--deep);
    font-size: clamp(28px, 5vw, 44px);
    line-height: 1.2;
}

.feature-list,
.check-list,
.number-list {
    padding: 0;
    margin: 18px 0 0;
    list-style: none;
}

.feature-list li,
.check-list li,
.number-list li {
    position: relative;
    margin: 10px 0;
    padding-left: 28px;
    color: #475467;
}

.feature-list li::before,
.check-list li::before {
    content: "";
    position: absolute;
    left: 0;
    top: 10px;
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--blue);
    box-shadow: 0 0 0 5px #eaf3ff;
}

.number-list {
    counter-reset: item;
}

.number-list li {
    counter-increment: item;
}

.number-list li::before {
    content: counter(item);
    position: absolute;
    left: 0;
    top: 0;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--blue);
    color: #fff;
    font-size: 12px;
    line-height: 20px;
    text-align: center;
    font-weight: 800;
}

.image-panel {
    padding: 14px;
    border-radius: 32px;
    background: linear-gradient(180deg, #ffffff 0%, #eef5ff 100%);
    border: 1px solid var(--line);
    box-shadow: var(--shadow);
}

.image-panel img {
    border-radius: 24px;
}

.global-nodes-section {
    position: relative;
    padding: 38px;
    border-radius: 32px;
    overflow: hidden;
    background: linear-gradient(135deg, #f7faff 0%, #ffffff 44%, #f1f5ff 100%);
    border: 1px solid var(--line);
}

.global-nodes-section::before {
    content: "";
    position: absolute;
    inset: 0;
    opacity: 0.55;
    background-image: radial-gradient(circle at 20% 20%, #2980FE 0 3px, transparent 4px), radial-gradient(circle at 76% 34%, #7B4EF1 0 3px, transparent 4px), radial-gradient(circle at 56% 76%, #B84DDA 0 3px, transparent 4px), linear-gradient(120deg, transparent 0 42%, rgba(41, 128, 254, 0.16) 42.1% 42.5%, transparent 42.8% 100%);
    background-size: 220px 220px, 250px 250px, 260px 260px, 100% 100%;
}

.global-nodes-section > * {
    position: relative;
    z-index: 1;
}

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

.speed-line {
    height: 10px;
    border-radius: 999px;
    background: linear-gradient(90deg, #d8e7ff 0%, #2980FE 70%, #7B4EF1 100%);
    margin: 12px 0;
}

.security-panel {
    padding: 24px;
    border-radius: 28px;
    background: #fff;
    border: 1px solid var(--line);
    box-shadow: var(--shadow);
}

.security-panel h3 {
    margin-top: 0;
}

.tag-row span {
    background: #edf5ff;
    color: var(--blue);
}

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

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

.protocol-row {
    padding: 18px;
    border-radius: 20px;
    border: 1px solid var(--line);
    background: #fff;
}

.protocol-row strong {
    color: var(--deep);
}

.process-steps {
    counter-reset: steps;
}

.step-card {
    position: relative;
    padding-top: 52px;
}

.step-card::before {
    counter-increment: steps;
    content: counter(steps, decimal-leading-zero);
    position: absolute;
    top: 18px;
    left: 22px;
    color: var(--blue);
    font-weight: 900;
    font-size: 18px;
}

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

.risk-card .action {
    margin-top: 10px;
    padding: 10px 12px;
    border-radius: 14px;
    background: #f4f8ff;
    color: #344054;
    font-size: 14px;
}

.faq-item h3 {
    margin: 0 0 8px;
    color: var(--deep);
}

.cta-section {
    padding: 58px 0;
    color: #fff;
    background: var(--purple-gradient);
}

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

.cta-box h2 {
    margin: 0 0 12px;
    font-size: clamp(28px, 5vw, 44px);
    line-height: 1.2;
}

.cta-box p {
    margin: 0 auto 22px;
    max-width: 660px;
    color: rgba(255, 255, 255, 0.86);
}

.page-hero {
    padding: 54px 0 34px;
    background: linear-gradient(180deg, #f5f8ff 0%, #ffffff 100%);
}

.page-hero h1 {
    font-size: clamp(32px, 6vw, 54px);
}

.page-hero p {
    max-width: 760px;
    font-size: 17px;
}

.article-layout {
    display: grid;
    grid-template-columns: 1fr;
    gap: 24px;
    align-items: start;
}

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

.article-main p {
    color: #475467;
}

.article-card h2,
.article-card h3 {
    margin-top: 0;
}

.tip-box {
    padding: 20px;
    background: #f8fbff;
}

.sidebar {
    display: grid;
    gap: 16px;
}

.sidebar .card {
    position: sticky;
    top: 94px;
}

.download-center {
    display: grid;
    grid-template-columns: 1fr;
    gap: 22px;
    align-items: center;
}

.download-panel {
    padding: 28px;
    border-radius: 30px;
    background: var(--purple-gradient);
    color: #fff;
    box-shadow: var(--shadow);
}

.download-panel p {
    color: rgba(255, 255, 255, 0.86);
}

.download-steps {
    display: grid;
    gap: 14px;
}

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

.site-footer {
    padding: 44px 0;
    background: #101828;
    color: #d0d5dd;
}

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

.footer-brand strong {
    display: block;
    color: #fff;
}

.footer-brand p,
.footer-note {
    margin: 4px 0 0;
    color: #98a2b3;
}

.footer-links {
    display: flex;
    flex-wrap: wrap;
    gap: 12px 18px;
}

.footer-links a {
    color: #e4e7ec;
    font-weight: 650;
}

@media (min-width: 720px) {
    .node-grid,
    .feature-grid,
    .policy-grid,
    .risk-grid,
    .faq-grid,
    .cards-grid,
    .process-steps {
        grid-template-columns: repeat(2, 1fr);
    }

    .download-center {
        grid-template-columns: 0.95fr 1.05fr;
    }
}

@media (min-width: 980px) {
    .nav-toggle {
        display: none;
    }

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

    .site-nav a {
        padding: 8px 10px;
        font-size: 14px;
    }

    .hero-grid {
        grid-template-columns: 1.05fr 0.95fr;
        min-height: 560px;
    }

    .float-card {
        display: block;
    }

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

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

    .global-nodes-section {
        display: grid;
        grid-template-columns: 0.95fr 1.05fr;
        gap: 28px;
        align-items: center;
    }

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

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

    .article-layout {
        grid-template-columns: minmax(0, 1fr) 310px;
    }
}

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

    .section {
        padding: 46px 0;
    }

    .global-nodes-section {
        padding: 24px;
    }

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