:root {
    --primary: #2980FE;
    --primary-hover: #1768E8;
    --gradient: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    --text: #1f2937;
    --muted: #667085;
    --light: #f5f7fb;
    --soft-blue: #eef5ff;
    --border: #e4e7ec;
    --card: #ffffff;
    --deep: #101828;
    --radius-lg: 28px;
    --radius-md: 20px;
    --shadow: 0 18px 48px rgba(28, 49, 103, .10);
    --soft-shadow: 0 10px 30px rgba(28, 49, 103, .08);
}

* { box-sizing: border-box; }
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: #fff;
    line-height: 1.7;
    overflow-x: hidden;
}
img { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }
.container { width: min(1120px, calc(100% - 32px)); margin: 0 auto; }

.site-header {
    position: sticky;
    top: 0;
    z-index: 20;
    background: rgba(255,255,255,.94);
    backdrop-filter: blur(18px);
    border-bottom: 1px solid rgba(228,231,236,.9);
}
.nav-shell {
    min-height: 68px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
}
.brand,
.footer-brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-weight: 800;
    letter-spacing: .02em;
    color: var(--deep);
}
.brand-logo,
.footer-logo {
    width: 42px;
    height: 42px;
    border-radius: 13px;
    object-fit: cover;
    box-shadow: 0 8px 20px rgba(41,128,254,.20);
}
.brand-text { font-size: 20px; }
.nav-toggle { display: none; }
.nav-toggle-label {
    width: 44px;
    height: 44px;
    border: 1px solid var(--border);
    border-radius: 14px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    background: #fff;
}
.nav-toggle-label span,
.nav-toggle-label span::before,
.nav-toggle-label span::after {
    display: block;
    width: 20px;
    height: 2px;
    background: var(--deep);
    border-radius: 2px;
    position: relative;
}
.nav-toggle-label span::before,
.nav-toggle-label span::after { content: ""; position: absolute; left: 0; }
.nav-toggle-label span::before { top: -7px; }
.nav-toggle-label span::after { top: 7px; }
.site-nav {
    position: absolute;
    left: 16px;
    right: 16px;
    top: 74px;
    display: none;
    flex-direction: column;
    gap: 4px;
    padding: 12px;
    background: #fff;
    border: 1px solid var(--border);
    border-radius: 22px;
    box-shadow: var(--shadow);
}
.nav-toggle:checked ~ .site-nav { display: flex; }
.site-nav a {
    padding: 11px 14px;
    border-radius: 14px;
    color: #475467;
    font-weight: 650;
    font-size: 15px;
}
.site-nav a:hover,
.site-nav a.active { color: var(--primary); background: var(--soft-blue); }

.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 12px 24px;
    border-radius: 999px;
    background: #2980FE;
    color: #fff;
    font-weight: 800;
    box-shadow: 0 12px 26px rgba(41, 128, 254, .28);
    transition: transform .2s ease, background .2s ease, box-shadow .2s ease;
}
.download-btn:hover { background: #1768E8; transform: translateY(-1px); box-shadow: 0 16px 30px rgba(23,104,232,.34); }
.text-link { color: var(--primary); font-weight: 750; }
.text-link:hover { color: var(--primary-hover); }
.section { padding: 64px 0; }
.section-soft { background: var(--light); }
.section-head { max-width: 720px; margin: 0 auto 28px; text-align: center; }
.section-eyebrow,
.badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 12px;
    border-radius: 999px;
    background: var(--soft-blue);
    color: var(--primary);
    font-weight: 800;
    font-size: 13px;
}
h1, h2, h3 { line-height: 1.2; color: var(--deep); margin: 0 0 14px; }
h1 { font-size: clamp(34px, 7vw, 62px); letter-spacing: -0.04em; }
h2 { font-size: clamp(26px, 4vw, 40px); letter-spacing: -0.03em; }
h3 { font-size: 20px; }
p { margin: 0 0 14px; color: var(--muted); }
ul, ol { color: var(--muted); padding-left: 20px; margin: 10px 0 0; }

.vpn-network-hero {
    position: relative;
    overflow: hidden;
    background: var(--gradient);
    color: #fff;
    min-height: 620px;
    padding: 74px 0 54px;
}
.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: -190px;
    top: -150px;
    background: rgba(255,255,255,.16);
    filter: blur(4px);
}
.vpn-network-hero::after {
    width: 380px;
    height: 380px;
    left: -140px;
    bottom: -170px;
    background: rgba(255,255,255,.13);
}
.hero-grid {
    position: relative;
    z-index: 1;
    display: grid;
    gap: 34px;
    align-items: center;
}
.hero-copy h1,
.hero-copy p { color: #fff; }
.hero-copy p { font-size: 17px; max-width: 660px; opacity: .92; }
.hero-tags,
.float-tags,
.mini-tags { display: flex; flex-wrap: wrap; gap: 10px; margin: 22px 0 0; }
.hero-tags span,
.float-tags span,
.mini-tags span {
    display: inline-flex;
    padding: 8px 12px;
    border-radius: 999px;
    background: rgba(255,255,255,.17);
    border: 1px solid rgba(255,255,255,.25);
    color: #fff;
    font-size: 13px;
    font-weight: 700;
}
.hero-visual { position: relative; }
.hero-card {
    position: relative;
    border: 1px solid rgba(255,255,255,.26);
    background: rgba(255,255,255,.16);
    border-radius: 32px;
    padding: 20px;
    box-shadow: 0 30px 70px rgba(14,31,70,.25);
}
.hero-card::before {
    content: "";
    position: absolute;
    inset: 20px;
    border-radius: 28px;
    background-image:
        radial-gradient(circle at 20% 25%, rgba(255,255,255,.75) 0 3px, transparent 4px),
        radial-gradient(circle at 68% 30%, rgba(255,255,255,.65) 0 3px, transparent 4px),
        radial-gradient(circle at 82% 70%, rgba(255,255,255,.55) 0 3px, transparent 4px),
        linear-gradient(120deg, transparent 0 24%, rgba(255,255,255,.25) 25%, transparent 38%),
        linear-gradient(40deg, transparent 0 44%, rgba(255,255,255,.18) 45%, transparent 55%);
    opacity: .8;
}
.hero-card img { position: relative; z-index: 1; margin: 0 auto; border-radius: 26px; }
.status-pill {
    position: absolute;
    z-index: 2;
    right: 8px;
    top: 8px;
    background: #fff;
    color: var(--deep);
    padding: 10px 14px;
    border-radius: 999px;
    box-shadow: var(--soft-shadow);
    font-weight: 800;
    font-size: 13px;
}
.float-tags { margin-top: 14px; }

.node-overview {
    margin-top: -38px;
    position: relative;
    z-index: 3;
}
.node-overview-grid,
.feature-grid,
.risk-grid,
.faq-grid,
.card-grid,
.policy-grid,
.device-grid {
    display: grid;
    gap: 16px;
}
.node-card,
.feature-card,
.risk-card,
.faq-item,
.policy-card,
.device-card,
.step-card,
.info-card,
.aside-card {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: 22px;
    box-shadow: var(--soft-shadow);
}
.node-card .tag,
.feature-card .tag,
.info-card .tag {
    display: inline-flex;
    margin-bottom: 12px;
    color: var(--primary);
    background: var(--soft-blue);
    border-radius: 999px;
    padding: 5px 10px;
    font-size: 12px;
    font-weight: 800;
}

.vpn-connection-section,
.global-nodes-section,
.high-speed-section,
.privacy-protection-section,
.multi-device-section,
.encryption-protocol-section,
.split-section {
    display: grid;
    gap: 28px;
    align-items: center;
}
.visual-panel,
.security-panel,
.tech-panel,
.map-panel,
.speed-panel {
    background: #fff;
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 20px;
    box-shadow: var(--shadow);
    overflow: hidden;
}
.visual-panel img,
.security-panel img,
.map-panel img,
.speed-panel img { border-radius: 22px; margin: 0 auto; }
.check-list {
    display: grid;
    gap: 12px;
    margin: 20px 0;
}
.check-item {
    display: flex;
    gap: 10px;
    align-items: flex-start;
    color: var(--muted);
}
.check-item::before {
    content: "";
    width: 18px;
    height: 18px;
    border-radius: 50%;
    margin-top: 4px;
    background: var(--primary);
    box-shadow: inset 0 0 0 5px #fff, 0 0 0 1px var(--primary);
    flex: 0 0 18px;
}
.global-nodes-wrap {
    border-radius: 34px;
    padding: 28px;
    background:
        radial-gradient(circle at 15% 25%, rgba(41,128,254,.16), transparent 30%),
        radial-gradient(circle at 80% 30%, rgba(123,78,241,.13), transparent 28%),
        #f8fbff;
    border: 1px solid #dde8f7;
}
.map-panel {
    background-image:
        radial-gradient(circle at 18% 35%, rgba(41,128,254,.25) 0 4px, transparent 5px),
        radial-gradient(circle at 64% 28%, rgba(123,78,241,.25) 0 4px, transparent 5px),
        radial-gradient(circle at 78% 70%, rgba(184,77,218,.22) 0 4px, transparent 5px),
        linear-gradient(115deg, transparent 0 34%, rgba(41,128,254,.13) 35%, transparent 45%),
        linear-gradient(45deg, transparent 0 50%, rgba(123,78,241,.12) 51%, transparent 60%);
}
.speed-lines {
    display: grid;
    gap: 12px;
    margin-top: 16px;
}
.speed-line {
    padding: 14px;
    border: 1px solid var(--border);
    border-radius: 16px;
    background: #fff;
}
.speed-line b { color: var(--deep); }
.progress {
    height: 8px;
    margin-top: 10px;
    border-radius: 999px;
    background: #edf2f7;
    overflow: hidden;
}
.progress span { display: block; height: 100%; border-radius: inherit; background: var(--primary); }
.security-panel .mini-tags span { background: var(--soft-blue); color: var(--primary); border-color: transparent; }
.no-log-policy-section .policy-card { border-top: 4px solid var(--primary); }
.device-card { display: grid; gap: 12px; }
.device-icon {
    width: 48px;
    height: 48px;
    border-radius: 16px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background: var(--soft-blue);
    color: var(--primary);
    font-weight: 900;
}
.tech-panel {
    background:
        linear-gradient(180deg, rgba(41,128,254,.08), rgba(255,255,255,0)),
        #fff;
}
.protocol-row {
    display: grid;
    gap: 12px;
    margin-top: 16px;
}
.protocol-row div {
    padding: 16px;
    border-radius: 16px;
    border: 1px solid var(--border);
    background: #fff;
}
.process-steps {
    display: grid;
    gap: 16px;
}
.step-number {
    width: 42px;
    height: 42px;
    border-radius: 14px;
    background: var(--primary);
    color: #fff;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-weight: 900;
    margin-bottom: 12px;
}
.risk-card { border-left: 4px solid var(--primary); }
.risk-card strong { display: block; color: var(--deep); margin-bottom: 6px; }
.faq-item h3 { font-size: 18px; }
.cta-section {
    padding: 60px 0;
    background: var(--gradient);
    color: #fff;
    text-align: center;
    overflow: hidden;
}
.cta-section h2,
.cta-section p { color: #fff; }
.cta-box { max-width: 760px; margin: 0 auto; }
.cta-box p { opacity: .9; }

.page-hero {
    padding: 54px 0 32px;
    background:
        radial-gradient(circle at 20% 10%, rgba(41,128,254,.12), transparent 28%),
        radial-gradient(circle at 90% 20%, rgba(184,77,218,.12), transparent 30%),
        #f8fbff;
    border-bottom: 1px solid var(--border);
}
.page-hero .summary { max-width: 780px; font-size: 17px; }
.page-layout {
    display: grid;
    gap: 24px;
    align-items: start;
}
.article-content {
    background: #fff;
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 24px;
    box-shadow: var(--soft-shadow);
}
.article-content h2 { font-size: 26px; margin-top: 26px; }
.note-box {
    padding: 18px;
    border-radius: 18px;
    background: var(--soft-blue);
    border: 1px solid #d6e7ff;
    margin: 18px 0;
}
.note-box p { margin: 0; }
.action-row { margin-top: 22px; }
.aside-card { position: sticky; top: 92px; }
.aside-card a { display: block; color: var(--primary); font-weight: 750; margin: 10px 0; }
.download-steps,
.safe-list { display: grid; gap: 14px; counter-reset: item; }
.download-steps li,
.safe-list li {
    list-style: none;
    padding: 16px;
    border: 1px solid var(--border);
    border-radius: 18px;
    background: #fff;
}
.download-card {
    max-width: 820px;
    margin: 0 auto;
    text-align: center;
    background: #fff;
    border: 1px solid var(--border);
    border-radius: 30px;
    padding: 28px;
    box-shadow: var(--shadow);
}
.download-card .download-btn { margin: 10px 0 22px; }

.site-footer {
    background: #101828;
    color: #fff;
    padding: 46px 0 24px;
}
.footer-grid { display: grid; gap: 24px; }
.site-footer p,
.site-footer a { color: rgba(255,255,255,.72); }
.site-footer h3 { color: #fff; font-size: 16px; margin-bottom: 12px; }
.site-footer a { display: block; margin: 7px 0; }
.footer-bottom {
    border-top: 1px solid rgba(255,255,255,.12);
    margin-top: 28px;
    padding-top: 18px;
}
.footer-bottom p { margin: 0; font-size: 14px; }

@media (min-width: 640px) {
    .node-overview-grid,
    .feature-grid,
    .policy-grid,
    .device-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .risk-grid,
    .faq-grid,
    .process-steps { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .article-content { padding: 32px; }
}

@media (min-width: 920px) {
    .nav-toggle-label { display: none; }
    .site-nav {
        position: static;
        display: flex;
        flex-direction: row;
        align-items: center;
        gap: 2px;
        padding: 0;
        border: 0;
        box-shadow: none;
        background: transparent;
    }
    .site-nav a { padding: 9px 10px; font-size: 14px; }
    .hero-grid { grid-template-columns: 1.03fr .97fr; }
    .vpn-network-hero { padding: 96px 0 74px; }
    .node-overview-grid { grid-template-columns: repeat(4, minmax(0, 1fr)); }
    .vpn-connection-section,
    .global-nodes-section,
    .high-speed-section,
    .privacy-protection-section,
    .multi-device-section,
    .encryption-protocol-section,
    .split-section { grid-template-columns: repeat(2, minmax(0, 1fr)); }
    .no-log-policy-section .policy-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
    .risk-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
    .page-layout { grid-template-columns: minmax(0, 1fr) 300px; }
    .footer-grid { grid-template-columns: 1.4fr repeat(3, 1fr); }
    .section { padding: 86px 0; }
}

@media (min-width: 1120px) {
    .site-nav a { padding: 10px 12px; }
    .process-steps { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}

@media (max-width: 480px) {
    .container { width: min(100% - 24px, 1120px); }
    .vpn-network-hero { min-height: auto; padding-top: 54px; }
    .download-btn { width: 100%; min-height: 52px; }
    .hero-tags span,
    .float-tags span { font-size: 12px; }
    .node-card,
    .feature-card,
    .risk-card,
    .faq-item,
    .policy-card,
    .device-card,
    .step-card,
    .info-card,
    .article-content { padding: 18px; }
}