:root {
    --primary: #2980FE;
    --primary-dark: #1768E8;
    --gradient: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    --text: #1f2937;
    --muted: #667085;
    --light: #f5f7fb;
    --soft-blue: #eef5ff;
    --border: #e5e9f2;
    --white: #ffffff;
    --shadow: 0 18px 45px rgba(27, 46, 94, 0.10);
    --radius: 24px;
}

* {
    box-sizing: border-box;
}

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%;
    height: auto;
    display: block;
}

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

p {
    margin: 0 0 16px;
}

.site-header {
    position: sticky;
    top: 0;
    z-index: 20;
    background: rgba(255, 255, 255, 0.96);
    border-bottom: 1px solid rgba(229, 233, 242, 0.9);
    backdrop-filter: blur(14px);
}

.header-inner {
    max-width: 1180px;
    margin: 0 auto;
    padding: 14px 18px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
}

.logo {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-weight: 800;
    color: #182033;
    letter-spacing: -0.02em;
}

.logo img {
    width: 42px;
    height: 42px;
    border-radius: 12px;
    object-fit: cover;
}

.desktop-nav {
    display: none;
    align-items: center;
    gap: 22px;
    color: #344054;
    font-size: 15px;
}

.desktop-nav a {
    transition: color .2s ease;
}

.desktop-nav a:hover {
    color: var(--primary);
}

.mobile-menu {
    position: relative;
}

.mobile-menu summary {
    list-style: none;
    cursor: pointer;
    color: var(--primary);
    font-weight: 700;
    border: 1px solid var(--border);
    border-radius: 999px;
    padding: 8px 14px;
}

.mobile-menu summary::-webkit-details-marker {
    display: none;
}

.mobile-menu nav {
    position: absolute;
    right: 0;
    top: 46px;
    min-width: 210px;
    padding: 12px;
    display: grid;
    gap: 6px;
    background: var(--white);
    border: 1px solid var(--border);
    box-shadow: var(--shadow);
    border-radius: 18px;
}

.mobile-menu nav a {
    padding: 10px 12px;
    border-radius: 12px;
    color: #344054;
}

.mobile-menu nav a:hover {
    background: var(--soft-blue);
    color: var(--primary);
}

.content-container {
    width: min(100% - 36px, 1180px);
    margin: 0 auto;
}

.section {
    padding: 58px 0;
}

.section-title {
    font-size: clamp(28px, 4vw, 44px);
    line-height: 1.18;
    margin: 0 0 14px;
    letter-spacing: -0.04em;
    color: #172033;
}

.section-kicker,
.badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 14px;
    padding: 6px 12px;
    border-radius: 999px;
    background: #edf5ff;
    color: var(--primary);
    font-weight: 700;
    font-size: 13px;
}

.section-lead {
    color: var(--muted);
    font-size: 17px;
    max-width: 760px;
}

.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 12px 24px;
    border-radius: 999px;
    background: #2980FE;
    color: #ffffff;
    font-weight: 800;
    box-shadow: 0 12px 24px rgba(41, 128, 254, 0.24);
    transition: transform .2s ease, background .2s ease, box-shadow .2s ease;
}

.download-btn:hover {
    background: #1768E8;
    transform: translateY(-2px);
    box-shadow: 0 14px 28px rgba(23, 104, 232, 0.28);
}

.link-arrow {
    color: var(--primary);
    font-weight: 700;
}

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

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

.vpn-network-hero::before,
.vpn-network-hero::after {
    content: "";
    position: absolute;
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.18);
    filter: blur(8px);
}

.vpn-network-hero::before {
    width: 330px;
    height: 330px;
    right: -80px;
    top: -110px;
}

.vpn-network-hero::after {
    width: 280px;
    height: 280px;
    left: -120px;
    bottom: -130px;
}

.hero-inner {
    position: relative;
    z-index: 1;
    width: min(100% - 36px, 1180px);
    margin: 0 auto;
    padding: 70px 0 78px;
    display: grid;
    gap: 36px;
}

.hero-copy h1 {
    font-size: clamp(38px, 8vw, 72px);
    line-height: 1.04;
    margin: 0 0 18px;
    letter-spacing: -0.06em;
}

.hero-copy p {
    font-size: 18px;
    color: rgba(255, 255, 255, 0.88);
    max-width: 650px;
}

.hero-actions {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 16px;
    margin: 26px 0;
}

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

.hero-tags span,
.floating-tags span {
    border: 1px solid rgba(255, 255, 255, 0.28);
    background: rgba(255, 255, 255, 0.14);
    color: #ffffff;
    padding: 8px 12px;
    border-radius: 999px;
    font-weight: 700;
    font-size: 13px;
}

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

.network-orbit {
    position: absolute;
    inset: 10px;
    border: 1px solid rgba(255, 255, 255, 0.22);
    border-radius: 36px;
    background:
        radial-gradient(circle at 22% 28%, rgba(255,255,255,.45) 0 3px, transparent 4px),
        radial-gradient(circle at 78% 30%, rgba(255,255,255,.35) 0 4px, transparent 5px),
        radial-gradient(circle at 55% 72%, rgba(255,255,255,.34) 0 3px, transparent 4px),
        linear-gradient(135deg, rgba(255,255,255,.16), rgba(255,255,255,.05));
}

.hero-device {
    position: relative;
    z-index: 2;
    width: min(420px, 88%);
    border-radius: 30px;
    box-shadow: 0 24px 70px rgba(0, 0, 0, 0.20);
}

.status-card {
    position: absolute;
    z-index: 3;
    padding: 10px 14px;
    border-radius: 16px;
    background: rgba(255, 255, 255, 0.92);
    color: #253047;
    box-shadow: 0 16px 34px rgba(27, 46, 94, 0.18);
    font-weight: 800;
    font-size: 13px;
}

.status-card.one { left: 6px; top: 28px; }
.status-card.two { right: 8px; top: 84px; }
.status-card.three { left: 12px; bottom: 76px; }
.status-card.four { right: 14px; bottom: 18px; }

.node-overview {
    margin-top: -40px;
    position: relative;
    z-index: 4;
}

.node-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 16px;
}

.node-card,
.feature-card,
.info-card,
.faq-item,
.risk-card,
.step-card {
    background: var(--white);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: 0 10px 34px rgba(27, 46, 94, 0.06);
}

.node-card {
    padding: 22px;
}

.node-card small {
    display: inline-flex;
    padding: 4px 10px;
    border-radius: 999px;
    background: #edf5ff;
    color: var(--primary);
    font-weight: 800;
    margin-bottom: 12px;
}

.node-card h3,
.feature-card h3,
.info-card h3,
.risk-card h3,
.step-card h3 {
    margin: 0 0 8px;
    color: #182033;
    line-height: 1.25;
}

.node-card p,
.feature-card p,
.info-card p,
.risk-card p,
.step-card p {
    color: var(--muted);
}

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

.visual-panel {
    position: relative;
    padding: 18px;
    border-radius: 30px;
    background: linear-gradient(135deg, #f8fbff, #eef5ff);
    border: 1px solid var(--border);
    box-shadow: var(--shadow);
}

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

.check-list {
    display: grid;
    gap: 12px;
    margin: 22px 0;
    padding: 0;
    list-style: none;
}

.check-list li {
    padding: 14px 16px;
    border-radius: 16px;
    background: #f7f9fc;
    border: 1px solid var(--border);
    color: #344054;
}

.check-list li::before {
    content: "✓";
    color: var(--primary);
    font-weight: 900;
    margin-right: 8px;
}

.vpn-connection-section,
.privacy-protection-section,
.multi-device-section {
    background: #ffffff;
}

.global-nodes-section {
    position: relative;
    overflow: hidden;
    background:
        radial-gradient(circle at 20% 24%, rgba(41, 128, 254, 0.15), transparent 28%),
        radial-gradient(circle at 80% 35%, rgba(123, 78, 241, 0.14), transparent 30%),
        #f8fbff;
}

.map-panel {
    min-height: 360px;
    border-radius: 32px;
    padding: 24px;
    background:
        linear-gradient(90deg, rgba(41,128,254,.10) 1px, transparent 1px),
        linear-gradient(0deg, rgba(41,128,254,.10) 1px, transparent 1px),
        #ffffff;
    background-size: 42px 42px;
    border: 1px solid var(--border);
    box-shadow: var(--shadow);
    display: grid;
    align-items: center;
    gap: 18px;
}

.node-pill-group {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.node-pill {
    padding: 8px 12px;
    border-radius: 999px;
    background: #edf5ff;
    color: #2458b8;
    font-weight: 800;
    border: 1px solid #d8e8ff;
}

.high-speed-section {
    background: #f5f8fc;
}

.speed-card {
    padding: 24px;
    border-radius: 28px;
    background: #ffffff;
    border: 1px solid var(--border);
    box-shadow: var(--shadow);
}

.speed-line {
    height: 12px;
    border-radius: 999px;
    margin: 16px 0;
    background: linear-gradient(90deg, #cfe3ff, #2980FE);
}

.privacy-panel {
    border-radius: 30px;
    background: #ffffff;
    border: 1px solid var(--border);
    box-shadow: var(--shadow);
    padding: 24px;
}

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

.privacy-tags span {
    padding: 8px 12px;
    border-radius: 999px;
    background: #f0f6ff;
    color: #2458b8;
    font-weight: 800;
    font-size: 13px;
}

.no-log-policy-section {
    background: #f8fafc;
}

.info-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 16px;
    margin-top: 26px;
}

.info-card,
.feature-card {
    padding: 24px;
}

.multi-device-layout {
    display: grid;
    gap: 22px;
}

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

.device-card {
    padding: 18px;
    border-radius: 22px;
    background: #f8fbff;
    border: 1px solid var(--border);
}

.encryption-protocol-section {
    background: #ffffff;
}

.tech-panel {
    display: grid;
    gap: 16px;
    padding: 24px;
    border-radius: 30px;
    background: linear-gradient(135deg, #f7fbff, #ffffff);
    border: 1px solid var(--border);
    box-shadow: var(--shadow);
}

.protocol-row {
    display: grid;
    gap: 8px;
    padding: 16px;
    border-radius: 18px;
    background: #ffffff;
    border: 1px solid var(--border);
}

.protocol-row strong {
    color: #182033;
}

.process-steps {
    background: #f5f8fc;
}

.steps-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 16px;
    margin-top: 26px;
}

.step-card {
    padding: 22px;
}

.step-number {
    width: 38px;
    height: 38px;
    display: grid;
    place-items: center;
    margin-bottom: 14px;
    border-radius: 50%;
    background: var(--primary);
    color: white;
    font-weight: 900;
}

.safety-panel {
    background: #ffffff;
}

.risk-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 16px;
    margin-top: 26px;
}

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

.faq-section {
    background: #f8fafc;
}

.faq-list {
    display: grid;
    gap: 16px;
    margin-top: 24px;
}

.faq-item {
    padding: 22px;
}

.faq-item h3 {
    margin: 0 0 8px;
    color: #172033;
}

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

.cta-section {
    background: var(--gradient);
    color: #ffffff;
    text-align: center;
}

.cta-box {
    width: min(100% - 36px, 920px);
    margin: 0 auto;
    padding: 56px 18px;
}

.cta-box h2 {
    margin: 0 0 12px;
    font-size: clamp(30px, 5vw, 48px);
    line-height: 1.16;
}

.cta-box p {
    color: rgba(255, 255, 255, 0.88);
    max-width: 720px;
    margin: 0 auto 26px;
}

.page-main {
    background: #ffffff;
}

.page-hero {
    padding: 56px 0 34px;
    background:
        radial-gradient(circle at 15% 20%, rgba(41, 128, 254, 0.12), transparent 28%),
        radial-gradient(circle at 85% 10%, rgba(184, 77, 218, 0.12), transparent 30%),
        #f8fbff;
}

.page-hero-inner {
    width: min(100% - 36px, 980px);
    margin: 0 auto;
}

.page-hero h1 {
    margin: 0 0 14px;
    font-size: clamp(34px, 7vw, 58px);
    line-height: 1.08;
    letter-spacing: -0.05em;
    color: #172033;
}

.page-hero p {
    font-size: 18px;
    color: var(--muted);
    max-width: 760px;
}

.page-content {
    width: min(100% - 36px, 980px);
    margin: 0 auto;
    padding: 36px 0 70px;
}

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

.article-card {
    padding: 24px;
    border-radius: 26px;
    background: #ffffff;
    border: 1px solid var(--border);
    box-shadow: 0 12px 32px rgba(27, 46, 94, 0.06);
}

.article-card h2 {
    margin: 0 0 12px;
    color: #172033;
}

.side-note {
    padding: 22px;
    border-radius: 24px;
    background: #f6f9ff;
    border: 1px solid #dce9ff;
}

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

.operation-list li,
.clean-list li {
    padding: 14px 16px;
    border-radius: 16px;
    background: #f8fafc;
    border: 1px solid var(--border);
}

.operation-list li strong {
    display: block;
    color: #172033;
    margin-bottom: 4px;
}

.download-area {
    margin-top: 24px;
}

.download-page-panel {
    display: grid;
    gap: 24px;
    align-items: center;
    padding: 26px;
    border-radius: 30px;
    background: #ffffff;
    border: 1px solid var(--border);
    box-shadow: var(--shadow);
}

.site-footer {
    background: #111827;
    color: #d1d5db;
}

.footer-inner {
    width: min(100% - 36px, 1180px);
    margin: 0 auto;
    padding: 42px 0;
}

.footer-brand {
    display: flex;
    gap: 14px;
    align-items: center;
    margin-bottom: 22px;
}

.footer-brand img {
    width: 46px;
    height: 46px;
    border-radius: 14px;
    object-fit: cover;
}

.footer-brand strong {
    color: #ffffff;
    font-size: 18px;
}

.footer-brand p,
.footer-note,
.copyright {
    margin: 0;
    color: #a8b0bd;
}

.footer-links {
    display: flex;
    flex-wrap: wrap;
    gap: 14px 22px;
    margin-bottom: 20px;
}

.footer-links a:hover {
    color: #ffffff;
}

@media (min-width: 640px) {
    .node-grid,
    .info-grid,
    .steps-grid,
    .risk-grid,
    .device-cards {
        grid-template-columns: repeat(2, 1fr);
    }

    .download-page-panel {
        grid-template-columns: 1.2fr .8fr;
    }
}

@media (min-width: 900px) {
    .desktop-nav {
        display: flex;
    }

    .mobile-menu {
        display: none;
    }

    .hero-inner {
        grid-template-columns: minmax(0, 1.08fr) minmax(320px, .92fr);
        align-items: center;
        padding: 92px 0 110px;
    }

    .split-section,
    .multi-device-layout {
        grid-template-columns: 1fr 1fr;
        gap: 48px;
    }

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

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

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

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

    .page-grid {
        grid-template-columns: 1fr 300px;
        align-items: start;
    }

    .section {
        padding: 82px 0;
    }
}

@media (min-width: 1100px) {
    .risk-grid {
        grid-template-columns: repeat(4, 1fr);
    }
}

@media (max-width: 420px) {
    .header-inner {
        padding: 12px 14px;
    }

    .content-container,
    .hero-inner,
    .page-content,
    .page-hero-inner,
    .footer-inner,
    .cta-box {
        width: min(100% - 28px, 1180px);
    }

    .download-btn {
        width: 100%;
    }

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

    .status-card {
        position: static;
        margin: 8px;
        display: inline-flex;
    }

    .hero-visual {
        align-items: start;
    }
}