:root {
    --gradient: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    --blue: #2980FE;
    --blue-dark: #1768E8;
    --text: #172033;
    --muted: #647084;
    --soft: #F5F7FB;
    --line: #E7ECF5;
    --panel: #FFFFFF;
    --deep: #263247;
    --shadow: 0 18px 45px rgba(31, 51, 94, .10);
    --radius: 28px;
}
* { 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;
    background: #fff;
    color: var(--text);
    line-height: 1.75;
    overflow-x: hidden;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; height: auto; display: block; }
main { background: linear-gradient(180deg, #ffffff 0%, #f8fbff 42%, #ffffff 100%); }
.container { width: min(1120px, calc(100% - 32px)); margin: 0 auto; }
.site-header {
    position: sticky;
    top: 0;
    z-index: 50;
    background: rgba(255,255,255,.92);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--line);
}
.header-inner {
    width: min(1180px, calc(100% - 28px));
    margin: 0 auto;
    min-height: 70px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
}
.brand { display: inline-flex; align-items: center; gap: 10px; font-weight: 800; color: #18233a; }
.logo-img { width: 38px; height: 38px; border-radius: 12px; object-fit: cover; box-shadow: 0 8px 18px rgba(41,128,254,.18); }
.brand-text { font-size: 20px; letter-spacing: .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: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 5px;
    background: #fff;
}
.nav-toggle-label span { width: 18px; height: 2px; background: #2b3954; border-radius: 2px; }
.site-nav {
    position: absolute;
    left: 14px;
    right: 14px;
    top: 78px;
    display: none;
    flex-direction: column;
    padding: 14px;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 24px;
    box-shadow: var(--shadow);
}
.nav-toggle:checked ~ .site-nav { display: flex; }
.site-nav a {
    padding: 12px 14px;
    border-radius: 14px;
    color: #47536a;
    font-size: 15px;
}
.site-nav a.active,
.site-nav a:hover { color: var(--blue); background: #F0F6FF; }
.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 0 26px;
    border-radius: 999px;
    background: var(--blue);
    color: #fff;
    font-weight: 700;
    box-shadow: 0 14px 24px rgba(41,128,254,.24);
    transition: transform .2s ease, background .2s ease, box-shadow .2s ease;
    border: 0;
}
.download-btn:hover { background: var(--blue-dark); transform: translateY(-2px); box-shadow: 0 16px 30px rgba(23,104,232,.26); }
.section { padding: 66px 0; }
.section-soft { background: #F7FAFF; }
.eyebrow, .badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: var(--blue);
    background: #EFF6FF;
    border: 1px solid #D9E8FF;
    border-radius: 999px;
    padding: 6px 12px;
    font-size: 13px;
    font-weight: 700;
}
.section-title { margin: 14px 0 12px; font-size: clamp(28px, 6vw, 44px); line-height: 1.18; letter-spacing: -0.03em; }
.section-lead { color: var(--muted); max-width: 760px; margin: 0; }
.link-more { color: var(--blue); font-weight: 700; display: inline-flex; margin-top: 18px; }
.vpn-lab-hero {
    background: var(--gradient);
    color: #fff;
    overflow: hidden;
    position: relative;
    padding: 66px 0 46px;
}
.vpn-lab-hero::before {
    content: "";
    position: absolute;
    inset: 0;
    background:
      radial-gradient(circle at 10% 20%, rgba(255,255,255,.22), transparent 26%),
      radial-gradient(circle at 85% 30%, rgba(255,255,255,.18), transparent 28%);
    pointer-events: none;
}
.hero-grid {
    position: relative;
    display: grid;
    gap: 34px;
    align-items: center;
}
.hero-copy h1 { font-size: clamp(36px, 9vw, 64px); line-height: 1.06; margin: 16px 0; letter-spacing: -0.05em; }
.hero-copy p { color: rgba(255,255,255,.88); font-size: 17px; margin: 0 0 24px; max-width: 620px; }
.hero-tags { display: flex; flex-wrap: wrap; gap: 10px; margin: 24px 0 0; }
.hero-tags span, .status-card {
    border: 1px solid rgba(255,255,255,.34);
    background: rgba(255,255,255,.14);
    color: #fff;
    border-radius: 999px;
    padding: 8px 13px;
    font-size: 13px;
    backdrop-filter: blur(10px);
}
.hero-visual {
    position: relative;
    min-height: 360px;
    display: flex;
    align-items: center;
    justify-content: center;
}
.device-shell {
    width: min(430px, 92vw);
    border-radius: 34px;
    padding: 18px;
    background: rgba(255,255,255,.28);
    border: 1px solid rgba(255,255,255,.38);
    box-shadow: 0 28px 80px rgba(22, 25, 90, .25);
}
.device-shell img { border-radius: 26px; background: #fff; }
.status-card { position: absolute; background: rgba(255,255,255,.86); color: #23304a; box-shadow: 0 16px 34px rgba(24, 33, 78, .18); }
.status-one { top: 18px; left: 4px; }
.status-two { top: 80px; right: 0; }
.status-three { bottom: 76px; left: 2px; }
.status-four { bottom: 26px; right: 16px; }
.privacy-summary {
    margin-top: -22px;
    position: relative;
    z-index: 3;
}
.summary-grid { display: grid; gap: 16px; }
.summary-card, .security-card, .info-card, .risk-card, .faq-item, .step-card, .tip-box {
    background: var(--panel);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 24px;
    box-shadow: 0 12px 30px rgba(35, 58, 102, .06);
}
.summary-card .mini-label { color: var(--blue); font-weight: 800; font-size: 13px; }
.summary-card h2, .summary-card h3, .security-card h3, .info-card h3, .risk-card h3, .step-card h3 { margin: 8px 0 8px; line-height: 1.28; }
.summary-card p, .security-card p, .info-card p, .risk-card p, .step-card p { color: var(--muted); margin: 0; }
.split-section {
    display: grid;
    gap: 28px;
    align-items: center;
}
.split-panel {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 34px;
    padding: 22px;
    box-shadow: var(--shadow);
}
.split-panel img { border-radius: 26px; }
.feature-list { display: grid; gap: 12px; margin: 22px 0 0; padding: 0; list-style: none; }
.feature-list li {
    display: flex;
    gap: 10px;
    align-items: flex-start;
    color: #3f4b63;
}
.feature-list li::before {
    content: "";
    width: 9px;
    height: 9px;
    margin-top: 10px;
    border-radius: 50%;
    background: var(--blue);
    flex: 0 0 9px;
}
.privacy-protection-section .privacy-panel,
.encryption-protocol-section .tech-panel {
    background: linear-gradient(180deg, #ffffff 0%, #f7fbff 100%);
    border: 1px solid var(--line);
    border-radius: 34px;
    padding: 26px;
    box-shadow: var(--shadow);
}
.tag-row { display: flex; flex-wrap: wrap; gap: 10px; margin: 18px 0; }
.tag-row span {
    color: #2d5dbe;
    background: #EEF6FF;
    border: 1px solid #DCEBFF;
    border-radius: 999px;
    padding: 7px 12px;
    font-size: 13px;
    font-weight: 700;
}
.no-log-policy-section .policy-grid,
.multi-device-section .device-grid,
.encryption-grid,
.risk-grid,
.faq-grid,
.page-card-grid {
    display: grid;
    gap: 16px;
}
.global-nodes-section .node-strip {
    margin-top: 20px;
    display: grid;
    gap: 12px;
}
.node-pill {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 18px;
    padding: 14px 16px;
    color: #3e4b63;
    box-shadow: 0 10px 20px rgba(44, 68, 114, .05);
}
.high-speed-section { background: #F6FAFF; }
.process-steps {
    display: grid;
    gap: 16px;
    counter-reset: step;
}
.step-card { position: relative; padding-top: 50px; }
.step-card::before {
    counter-increment: step;
    content: counter(step, decimal-leading-zero);
    position: absolute;
    top: 18px;
    left: 22px;
    color: var(--blue);
    font-weight: 900;
    letter-spacing: .08em;
}
.risk-card { border-left: 4px solid var(--blue); }
.risk-card strong { display: block; color: var(--deep); margin: 8px 0 4px; }
.faq-item h3 { margin: 0 0 10px; font-size: 18px; }
.faq-item p { margin: 0; color: var(--muted); }
.cta-section {
    padding: 62px 0;
    background: var(--gradient);
    color: #fff;
    text-align: center;
}
.cta-card {
    width: min(860px, calc(100% - 32px));
    margin: 0 auto;
}
.cta-card h2 { font-size: clamp(30px, 6vw, 48px); line-height: 1.15; margin: 0 0 14px; }
.cta-card p { color: rgba(255,255,255,.88); margin: 0 auto 24px; max-width: 680px; }
.page-hero {
    padding: 58px 0 38px;
    background: linear-gradient(180deg, #F4F8FF 0%, #FFFFFF 100%);
    border-bottom: 1px solid var(--line);
}
.page-hero h1 { margin: 16px 0 12px; font-size: clamp(32px, 7vw, 54px); line-height: 1.12; letter-spacing: -0.04em; }
.page-hero p { color: var(--muted); margin: 0; max-width: 820px; }
.content-layout { display: grid; gap: 26px; align-items: start; }
.article-panel {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 34px;
    padding: 26px;
    box-shadow: var(--shadow);
}
.article-panel h2 { margin-top: 0; font-size: 26px; }
.article-panel p { color: #45516a; }
.aside-panel {
    background: #F7FAFF;
    border: 1px solid var(--line);
    border-radius: 28px;
    padding: 22px;
}
.aside-panel h3 { margin-top: 0; }
.aside-panel a { display: block; color: var(--blue); font-weight: 700; margin-top: 10px; }
.check-list, .number-list { margin: 18px 0 0; padding-left: 20px; color: #43506a; }
.check-list li, .number-list li { margin: 8px 0; }
.download-page-grid { display: grid; gap: 18px; }
.site-footer {
    background: #172033;
    color: rgba(255,255,255,.78);
    padding: 48px 0 22px;
}
.footer-grid { display: grid; gap: 28px; }
.footer-brand { color: #fff; font-size: 24px; font-weight: 900; margin-bottom: 10px; }
.site-footer h3 { color: #fff; font-size: 16px; margin: 0 0 12px; }
.site-footer a { display: block; color: rgba(255,255,255,.72); margin: 8px 0; }
.site-footer a:hover { color: #fff; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,.12); margin-top: 28px; padding-top: 18px; font-size: 13px; }
@media (min-width: 720px) {
    .summary-grid { grid-template-columns: repeat(3, 1fr); }
    .policy-grid, .device-grid, .encryption-grid, .faq-grid, .page-card-grid { grid-template-columns: repeat(2, 1fr); }
    .risk-grid { grid-template-columns: repeat(2, 1fr); }
    .process-steps { grid-template-columns: repeat(2, 1fr); }
    .download-page-grid { grid-template-columns: repeat(2, 1fr); }
    .footer-grid { grid-template-columns: 1.5fr 1fr 1fr 1fr; }
}
@media (min-width: 980px) {
    .nav-toggle-label { display: none; }
    .site-nav {
        position: static;
        display: flex;
        flex-direction: row;
        align-items: center;
        gap: 2px;
        padding: 0;
        background: transparent;
        border: 0;
        border-radius: 0;
        box-shadow: none;
    }
    .site-nav a { padding: 9px 12px; }
    .vpn-lab-hero { padding: 86px 0 88px; }
    .hero-grid { grid-template-columns: 1.02fr .98fr; gap: 50px; }
    .summary-grid { gap: 20px; }
    .split-section { grid-template-columns: 1fr 1fr; gap: 54px; }
    .split-section.reverse .split-copy { order: 2; }
    .split-section.reverse .split-panel { order: 1; }
    .privacy-protection-section .split-section { grid-template-columns: .88fr 1.12fr; }
    .risk-grid { grid-template-columns: repeat(4, 1fr); }
    .process-steps { grid-template-columns: repeat(3, 1fr); }
    .content-layout { grid-template-columns: minmax(0, 1fr) 320px; }
    .article-panel { padding: 34px; }
    .page-hero { padding: 74px 0 54px; }
}
@media (max-width: 420px) {
    .container { width: min(100% - 24px, 1120px); }
    .section { padding: 48px 0; }
    .summary-card, .security-card, .info-card, .risk-card, .faq-item, .step-card, .article-panel { padding: 20px; border-radius: 22px; }
    .hero-visual { min-height: 300px; }
    .status-card { position: static; margin: 8px 4px; display: inline-flex; }
    .hero-visual { flex-wrap: wrap; }
    .device-shell { order: -1; }
    .download-btn { width: 100%; }
}