* {
    box-sizing: border-box;
}

:root {
    --gradient: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    --blue: #2980FE;
    --blue-dark: #1768E8;
    --text: #1f2937;
    --muted: #667085;
    --light: #f5f7fb;
    --line: #e5e7eb;
    --panel: #ffffff;
    --deep: #182238;
    --soft-blue: #eef5ff;
    --radius: 24px;
    --shadow: 0 18px 50px rgba(31, 41, 55, 0.10);
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", Arial, sans-serif;
    color: var(--text);
    background: #ffffff;
    line-height: 1.7;
    overflow-x: hidden;
}

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

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

.site-header {
    position: sticky;
    top: 0;
    z-index: 50;
    background: rgba(255, 255, 255, 0.94);
    backdrop-filter: blur(14px);
    border-bottom: 1px solid rgba(229, 231, 235, 0.85);
}

.header-inner {
    width: min(1160px, calc(100% - 32px));
    margin: 0 auto;
    min-height: 68px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
}

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

.brand-logo,
.footer-logo {
    width: 42px;
    height: 42px;
    border-radius: 14px;
    object-fit: cover;
    box-shadow: 0 8px 24px rgba(41, 128, 254, 0.18);
}

.brand-text {
    font-size: 20px;
    font-weight: 800;
    letter-spacing: 0.04em;
}

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

.nav-toggle-label {
    width: 42px;
    height: 42px;
    border: 1px solid var(--line);
    border-radius: 14px;
    display: grid;
    place-content: center;
    gap: 5px;
    cursor: pointer;
    background: #fff;
}

.nav-toggle-label span {
    width: 20px;
    height: 2px;
    background: var(--deep);
    display: block;
    border-radius: 5px;
}

.main-nav {
    position: absolute;
    left: 16px;
    right: 16px;
    top: 72px;
    display: none;
    flex-direction: column;
    padding: 14px;
    gap: 6px;
    border: 1px solid var(--line);
    border-radius: 20px;
    background: #fff;
    box-shadow: var(--shadow);
}

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

.main-nav a {
    padding: 10px 12px;
    border-radius: 12px;
    color: #475467;
    font-size: 14px;
    font-weight: 650;
}

.main-nav a.active,
.main-nav a:hover {
    color: var(--blue);
    background: var(--soft-blue);
}

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

.section {
    padding: 64px 0;
}

.section-muted {
    background: linear-gradient(180deg, #f7faff 0%, #ffffff 100%);
}

.section-title {
    font-size: clamp(28px, 4vw, 42px);
    line-height: 1.2;
    margin: 0 0 16px;
    color: var(--deep);
    letter-spacing: -0.03em;
}

.section-lead {
    margin: 0 0 28px;
    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: var(--blue);
    color: #fff;
    font-weight: 800;
    box-shadow: 0 14px 28px rgba(41, 128, 254, 0.28);
    transition: transform 0.2s ease, background 0.2s ease, box-shadow 0.2s ease;
    border: none;
}

.download-btn:hover {
    background: var(--blue-dark);
    transform: translateY(-1px);
    box-shadow: 0 16px 34px rgba(23, 104, 232, 0.32);
}

.text-link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    color: var(--blue);
    font-weight: 750;
    margin-top: 8px;
}

.text-link::after {
    content: "→";
}

.vpn-network-hero {
    position: relative;
    overflow: hidden;
    background: var(--gradient);
    color: #fff;
    padding: 68px 0 42px;
}

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

.vpn-network-hero::before {
    width: 420px;
    height: 420px;
    right: -120px;
    top: -120px;
    background: radial-gradient(circle, rgba(255,255,255,0.28), rgba(255,255,255,0));
}

.vpn-network-hero::after {
    width: 100%;
    height: 100%;
    left: 0;
    top: 0;
    background-image: radial-gradient(circle at 20% 30%, rgba(255,255,255,0.22) 0 2px, transparent 3px), radial-gradient(circle at 72% 42%, rgba(255,255,255,0.18) 0 2px, transparent 3px), radial-gradient(circle at 52% 72%, rgba(255,255,255,0.16) 0 2px, transparent 3px), linear-gradient(120deg, transparent 0 30%, rgba(255,255,255,0.13) 31%, transparent 32% 100%);
    opacity: 0.65;
}

.hero-grid {
    position: relative;
    z-index: 1;
    width: min(1160px, calc(100% - 32px));
    margin: 0 auto;
    display: grid;
    gap: 34px;
    align-items: center;
}

.hero-copy h1 {
    font-size: clamp(36px, 10vw, 68px);
    line-height: 1.05;
    margin: 0 0 20px;
    letter-spacing: -0.06em;
}

.hero-copy p {
    margin: 0 0 26px;
    color: rgba(255, 255, 255, 0.88);
    font-size: 17px;
}

.hero-tags,
.tag-row {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin: 24px 0 0;
}

.hero-tags span,
.status-pill,
.tag-row span,
.badge {
    display: inline-flex;
    align-items: center;
    border-radius: 999px;
    padding: 7px 12px;
    font-size: 13px;
    font-weight: 750;
}

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

.hero-visual {
    position: relative;
    min-height: 340px;
    display: grid;
    place-items: center;
}

.hero-device {
    width: min(420px, 92%);
    border-radius: 34px;
    box-shadow: 0 34px 80px rgba(15, 23, 42, 0.28);
    position: relative;
    z-index: 2;
}

.float-card {
    position: absolute;
    z-index: 3;
    background: rgba(255, 255, 255, 0.92);
    color: var(--deep);
    border: 1px solid rgba(255, 255, 255, 0.72);
    border-radius: 18px;
    padding: 10px 13px;
    box-shadow: 0 16px 45px rgba(15, 23, 42, 0.18);
    font-size: 13px;
    font-weight: 800;
}

.float-card.one { top: 18px; left: 4px; }
.float-card.two { top: 54px; right: 4px; }
.float-card.three { bottom: 70px; left: 0; }
.float-card.four { bottom: 24px; right: 18px; }

.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,
.check-card,
.help-card {
    background: var(--panel);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    box-shadow: 0 12px 34px rgba(15, 23, 42, 0.06);
}

.node-card {
    padding: 24px;
}

.node-label {
    display: inline-flex;
    padding: 4px 10px;
    background: var(--soft-blue);
    color: var(--blue);
    border-radius: 999px;
    font-size: 12px;
    font-weight: 850;
    margin-bottom: 12px;
}

.node-card h3,
.feature-card h3,
.info-card h3,
.step-card h3,
.risk-card h3,
.help-card h3 {
    margin: 0 0 10px;
    color: var(--deep);
    line-height: 1.3;
}

.node-card p,
.feature-card p,
.info-card p,
.step-card p,
.risk-card p,
.help-card p,
.page-copy p,
.article-panel p {
    color: var(--muted);
    margin: 0 0 14px;
}

.split-section,
.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;
}

.image-panel {
    background: linear-gradient(180deg, #ffffff 0%, #eef5ff 100%);
    border: 1px solid var(--line);
    border-radius: 32px;
    padding: 22px;
    box-shadow: var(--shadow);
    position: relative;
    overflow: hidden;
}

.image-panel::before {
    content: "";
    position: absolute;
    width: 180px;
    height: 180px;
    right: -55px;
    top: -55px;
    background: radial-gradient(circle, rgba(41,128,254,0.24), rgba(41,128,254,0));
}

.image-panel img {
    position: relative;
    z-index: 1;
    margin: 0 auto;
    border-radius: 26px;
}

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

.feature-list li,
.clean-list li {
    position: relative;
    padding-left: 26px;
    color: #475467;
}

.feature-list li::before,
.clean-list li::before {
    content: "";
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--blue);
    position: absolute;
    left: 0;
    top: 0.75em;
}

.map-panel {
    position: relative;
    min-height: 310px;
    border-radius: 34px;
    background: radial-gradient(circle at 20% 20%, rgba(41,128,254,0.18), transparent 24%), radial-gradient(circle at 74% 54%, rgba(184,77,218,0.16), transparent 25%), #ffffff;
    border: 1px solid var(--line);
    box-shadow: var(--shadow);
    padding: 24px;
    overflow: hidden;
}

.map-panel::before {
    content: "";
    position: absolute;
    inset: 28px;
    background-image: linear-gradient(115deg, transparent 0 47%, rgba(41,128,254,0.22) 48%, transparent 49% 100%), linear-gradient(30deg, transparent 0 54%, rgba(123,78,241,0.18) 55%, transparent 56% 100%);
    opacity: 0.75;
}

.map-panel img {
    position: relative;
    z-index: 1;
    margin: 0 auto;
    border-radius: 26px;
}

.map-dot {
    position: absolute;
    z-index: 2;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: var(--blue);
    box-shadow: 0 0 0 8px rgba(41, 128, 254, 0.12);
}

.map-dot.a { left: 20%; top: 28%; }
.map-dot.b { right: 26%; top: 42%; }
.map-dot.c { left: 42%; bottom: 22%; }

.speed-cards,
.policy-grid,
.protocol-grid,
.risk-grid,
.faq-grid,
.info-grid,
.related-grid,
.steps-grid,
.check-grid {
    display: grid;
    gap: 16px;
}

.speed-card,
.feature-card,
.info-card,
.step-card,
.check-card,
.help-card {
    padding: 22px;
}

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

.speed-line {
    height: 8px;
    border-radius: 999px;
    background: linear-gradient(90deg, rgba(41,128,254,0.12), rgba(41,128,254,0.9));
    margin-top: 12px;
}

.privacy-panel,
.safety-panel,
.article-panel {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 30px;
    padding: 28px;
    box-shadow: var(--shadow);
}

.safety-panel {
    border-left: 5px solid var(--blue);
}

.policy-card,
.protocol-card {
    padding: 24px;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 24px;
}

.device-stack {
    display: grid;
    grid-template-columns: 1fr;
    gap: 14px;
}

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

.device-card strong {
    color: var(--deep);
    display: block;
    margin-bottom: 6px;
}

.process-steps {
    position: relative;
}

.step-card .step-no {
    width: 38px;
    height: 38px;
    display: inline-grid;
    place-items: center;
    border-radius: 14px;
    background: var(--blue);
    color: #fff;
    font-weight: 850;
    margin-bottom: 14px;
}

.risk-card {
    padding: 22px;
    border-left: 4px solid var(--blue);
}

.faq-item {
    padding: 22px;
}

.faq-item h3 {
    margin: 0 0 10px;
    color: var(--deep);
}

.faq-item p {
    margin: 0;
    color: var(--muted);
}

.cta-section {
    background: var(--gradient);
    color: #fff;
    text-align: center;
    padding: 70px 0;
    position: relative;
    overflow: hidden;
}

.cta-section::before {
    content: "";
    position: absolute;
    width: 360px;
    height: 360px;
    left: -120px;
    top: -120px;
    background: radial-gradient(circle, rgba(255,255,255,0.24), transparent 60%);
}

.cta-section .container {
    position: relative;
    z-index: 1;
}

.cta-section h2 {
    margin: 0 0 14px;
    font-size: clamp(28px, 5vw, 44px);
    line-height: 1.2;
}

.cta-section p {
    color: rgba(255, 255, 255, 0.88);
    margin: 0 auto 24px;
    max-width: 720px;
}

.page-hero {
    background: linear-gradient(180deg, #f3f7ff 0%, #ffffff 100%);
    padding: 58px 0 30px;
}

.page-hero-inner {
    width: min(980px, calc(100% - 32px));
    margin: 0 auto;
}

.page-hero h1 {
    font-size: clamp(32px, 7vw, 54px);
    line-height: 1.15;
    color: var(--deep);
    margin: 16px 0;
    letter-spacing: -0.04em;
}

.page-summary {
    color: var(--muted);
    font-size: 17px;
    margin: 0;
    max-width: 760px;
}

.badge {
    color: var(--blue);
    background: var(--soft-blue);
    border: 1px solid rgba(41,128,254,0.16);
}

.page-layout {
    width: min(1080px, calc(100% - 32px));
    margin: 0 auto;
    padding: 34px 0 64px;
    display: grid;
    gap: 22px;
}

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

.article-panel h2,
.privacy-panel h2,
.safety-panel h2 {
    margin: 0 0 14px;
    color: var(--deep);
    line-height: 1.25;
}

.page-sidebar {
    display: grid;
    gap: 16px;
    align-content: start;
}

.sidebar-card {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 24px;
    padding: 22px;
    box-shadow: 0 10px 30px rgba(15, 23, 42, 0.05);
}

.sidebar-card h3 {
    margin: 0 0 10px;
    color: var(--deep);
}

.sidebar-card p,
.sidebar-card li {
    color: var(--muted);
}

.sidebar-card ul,
.article-panel ul,
.article-panel ol {
    padding-left: 20px;
    margin: 10px 0 0;
    color: var(--muted);
}

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

.download-steps {
    counter-reset: downloadStep;
}

.download-steps li {
    margin: 10px 0;
}

.site-footer {
    background: #f6f8fb;
    border-top: 1px solid var(--line);
    padding: 42px 0;
}

.footer-inner {
    width: min(1160px, calc(100% - 32px));
    margin: 0 auto;
    display: grid;
    gap: 24px;
}

.footer-brand p,
.footer-note p {
    margin: 4px 0 0;
    color: var(--muted);
}

.footer-links {
    display: flex;
    flex-wrap: wrap;
    gap: 10px 18px;
}

.footer-links a {
    color: #475467;
    font-weight: 650;
}

.footer-links a:hover {
    color: var(--blue);
}

@media (min-width: 640px) {
    .node-grid,
    .policy-grid,
    .protocol-grid,
    .risk-grid,
    .info-grid,
    .related-grid,
    .steps-grid,
    .check-grid,
    .faq-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}

@media (min-width: 860px) {
    .nav-toggle-label {
        display: none;
    }

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

    .main-nav a {
        padding: 9px 10px;
        white-space: nowrap;
    }

    .hero-grid,
    .vpn-connection-section,
    .global-nodes-section,
    .high-speed-section,
    .privacy-protection-section,
    .multi-device-section,
    .encryption-protocol-section,
    .split-section {
        grid-template-columns: minmax(0, 1.03fr) minmax(320px, 0.97fr);
    }

    .hero-grid {
        min-height: 560px;
    }

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

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

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

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

    .footer-inner {
        grid-template-columns: 1.1fr 1fr 1.1fr;
        align-items: start;
    }
}

@media (min-width: 1100px) {
    .main-nav a {
        padding: 10px 12px;
    }

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