:root {
    --gradient: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    --blue: #2980FE;
    --blue-hover: #1768E8;
    --text: #243047;
    --muted: #6B7280;
    --line: #E5EAF2;
    --soft: #F5F7FB;
    --soft-blue: #F1F6FF;
    --white: #FFFFFF;
    --radius-lg: 34px;
    --radius-md: 24px;
    --radius-sm: 18px;
    --shadow: 0 20px 60px rgba(31, 45, 78, .10);
}
* { 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: 1.75;
    overflow-x: hidden;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; height: auto; display: block; }
.container { width: min(100% - 32px, 1160px); margin: 0 auto; }
.section { padding: 64px 0; }
.section-soft { background: var(--soft); }
.section-title { max-width: 780px; margin-bottom: 28px; }
.section-title.center { margin-left: auto; margin-right: auto; text-align: center; }
.eyebrow, .category-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 7px 12px;
    border-radius: 999px;
    color: var(--blue);
    background: #EEF5FF;
    border: 1px solid #D8E8FF;
    font-size: 14px;
    font-weight: 700;
}
h1, h2, h3 { line-height: 1.22; margin: 0 0 16px; color: #14213D; }
h1 { font-size: clamp(34px, 7vw, 66px); letter-spacing: -1.8px; }
h2 { font-size: clamp(28px, 4vw, 44px); letter-spacing: -1px; }
h3 { font-size: 21px; }
p { margin: 0 0 18px; color: var(--muted); }
.lead { font-size: 18px; color: #516070; }
.site-header {
    position: sticky;
    top: 0;
    z-index: 50;
    background: rgba(255,255,255,.92);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid rgba(229,234,242,.85);
}
.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    min-height: 68px;
    position: relative;
}
.logo, .footer-logo {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-weight: 800;
    color: #172033;
    letter-spacing: .5px;
}
.logo img, .footer-logo img { width: 38px; height: 38px; border-radius: 12px; object-fit: cover; }
.nav-switch { display: none; }
.mobile-nav-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 8px 13px;
    border-radius: 999px;
    border: 1px solid var(--line);
    color: #172033;
    font-size: 14px;
    cursor: pointer;
    background: #fff;
}
.responsive-nav {
    position: absolute;
    left: 0;
    right: 0;
    top: 70px;
    display: none;
    flex-direction: column;
    gap: 6px;
    padding: 14px;
    border: 1px solid var(--line);
    border-radius: 20px;
    background: #fff;
    box-shadow: var(--shadow);
}
.nav-switch:checked ~ .responsive-nav { display: flex; }
.responsive-nav a {
    padding: 10px 12px;
    border-radius: 12px;
    color: #4A5568;
    font-size: 15px;
}
.responsive-nav a.active, .responsive-nav a:hover { color: var(--blue); background: #EEF5FF; }
.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: 800;
    box-shadow: 0 12px 24px rgba(41,128,254,.28);
    transition: transform .18s ease, background .18s ease, box-shadow .18s ease;
}
.download-btn:hover { background: var(--blue-hover); transform: translateY(-2px); box-shadow: 0 16px 32px rgba(23,104,232,.30); }
.vpn-lab-hero {
    background: var(--gradient);
    color: #fff;
    padding: 58px 0 68px;
    position: relative;
    overflow: hidden;
}
.vpn-lab-hero:before, .cta-section:before {
    content: "";
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at 20% 20%, rgba(255,255,255,.24), transparent 28%), radial-gradient(circle at 82% 18%, rgba(255,255,255,.18), transparent 26%);
    pointer-events: none;
}
.hero-grid {
    position: relative;
    z-index: 1;
    display: grid;
    gap: 34px;
    align-items: center;
}
.hero-copy h1, .hero-copy p { color: #fff; }
.hero-copy .lead { max-width: 650px; color: rgba(255,255,255,.86); }
.hero-actions { display: flex; flex-wrap: wrap; gap: 14px; align-items: center; margin: 26px 0; }
.hero-note { color: rgba(255,255,255,.82); font-size: 14px; }
.security-tags { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 20px; }
.security-tags span {
    padding: 8px 12px;
    border-radius: 999px;
    border: 1px solid rgba(255,255,255,.34);
    background: rgba(255,255,255,.14);
    color: #fff;
    font-size: 14px;
}
.hero-visual { position: relative; min-height: 340px; }
.product-panel {
    border: 1px solid rgba(255,255,255,.30);
    background: rgba(255,255,255,.14);
    border-radius: var(--radius-lg);
    padding: 22px;
    box-shadow: 0 24px 70px rgba(20,33,61,.24);
    backdrop-filter: blur(16px);
}
.product-panel img { width: min(100%, 430px); margin: 0 auto; border-radius: 26px; }
.float-card {
    position: absolute;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 14px;
    border-radius: 16px;
    background: rgba(255,255,255,.94);
    color: #243047;
    box-shadow: 0 14px 34px rgba(31,45,78,.18);
    font-size: 14px;
    font-weight: 700;
}
.float-card.one { left: 8px; top: 12px; }
.float-card.two { right: 4px; top: 66px; }
.float-card.three { left: 16px; bottom: 72px; }
.float-card.four { right: 18px; bottom: 16px; }
.float-card:before { content: ""; width: 9px; height: 9px; border-radius: 50%; background: var(--blue); }
.privacy-summary { margin-top: -34px; position: relative; z-index: 2; }
.summary-grid, .card-grid, .risk-grid, .feature-grid { display: grid; gap: 18px; }
.summary-card, .security-card, .info-card, .faq-item, .risk-card, .step-card, .note-panel {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: var(--radius-md);
    padding: 24px;
    box-shadow: 0 12px 36px rgba(31,45,78,.06);
}
.summary-card strong, .mini-label { color: var(--blue); font-size: 14px; font-weight: 800; }
.summary-card a, .text-link, .related-links a { color: var(--blue); font-weight: 700; }
.vpn-connection-section, .global-nodes-section, .high-speed-section, .multi-device-section {
    display: grid;
    gap: 28px;
    align-items: center;
}
.visual-card {
    background: linear-gradient(180deg, #fff, #F5F9FF);
    border: 1px solid var(--line);
    border-radius: var(--radius-lg);
    padding: 24px;
    box-shadow: var(--shadow);
}
.visual-card img { border-radius: 26px; margin: auto; }
.bullet-list, .check-list { padding: 0; margin: 20px 0 0; list-style: none; display: grid; gap: 10px; }
.bullet-list li, .check-list li {
    position: relative;
    padding-left: 28px;
    color: #4D5A6B;
}
.bullet-list li:before, .check-list li:before {
    content: "";
    position: absolute;
    left: 0;
    top: 12px;
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--blue);
}
.privacy-protection-section {
    display: grid;
    gap: 22px;
    align-items: start;
}
.boundary-panel {
    display: grid;
    gap: 14px;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: var(--radius-lg);
    padding: 24px;
    box-shadow: var(--shadow);
}
.boundary-row {
    display: grid;
    gap: 4px;
    padding: 16px;
    border-radius: 18px;
    background: var(--soft-blue);
}
.no-log-policy-section, .encryption-protocol-section, .safety-panel {
    border-radius: var(--radius-lg);
    border: 1px solid var(--line);
    background: #fff;
    padding: 28px;
    box-shadow: var(--shadow);
}
.policy-points, .protocol-grid {
    display: grid;
    gap: 16px;
    margin-top: 18px;
}
.policy-points div, .protocol-grid div {
    padding: 18px;
    border-radius: 20px;
    background: var(--soft);
    border: 1px solid var(--line);
}
.process-steps { display: grid; gap: 16px; counter-reset: step; }
.step-card { position: relative; padding-top: 52px; }
.step-card:before {
    counter-increment: step;
    content: counter(step, decimal-leading-zero);
    position: absolute;
    left: 22px;
    top: 18px;
    color: var(--blue);
    font-weight: 900;
    letter-spacing: .8px;
}
.risk-card { border-left: 4px solid var(--blue); }
.faq-list { display: grid; gap: 14px; }
.faq-item h3 { margin-bottom: 8px; }
.cta-section {
    position: relative;
    overflow: hidden;
    background: var(--gradient);
    color: #fff;
    text-align: center;
    padding: 72px 0;
}
.cta-section .container { position: relative; z-index: 1; }
.cta-section h2, .cta-section p { color: #fff; }
.cta-section p { max-width: 660px; margin-left: auto; margin-right: auto; color: rgba(255,255,255,.86); }
.page-hero {
    padding: 54px 0;
    background: linear-gradient(180deg, #F5F8FF, #FFFFFF);
    border-bottom: 1px solid var(--line);
}
.page-hero .container { max-width: 900px; }
.page-layout {
    display: grid;
    gap: 24px;
    padding: 56px 0;
}
.article-content {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: var(--radius-lg);
    padding: 26px;
    box-shadow: 0 12px 40px rgba(31,45,78,.06);
}
.article-content h2 { font-size: 28px; margin-top: 14px; }
.article-content .download-wrap { margin-top: 28px; }
.side-panel { display: grid; gap: 16px; align-content: start; }
.sidebar-card {
    border: 1px solid var(--line);
    border-radius: var(--radius-md);
    padding: 22px;
    background: var(--soft-blue);
}
.related-links { display: grid; gap: 10px; margin-top: 12px; }
.download-steps { display: grid; gap: 14px; margin: 24px 0; }
.download-steps div {
    padding: 18px;
    border-radius: 18px;
    background: var(--soft);
    border: 1px solid var(--line);
}
.site-footer { background: #111827; color: #D1D5DB; padding: 54px 0 24px; }
.footer-grid { display: grid; gap: 26px; }
.site-footer h3, .site-footer span { color: #fff; }
.site-footer p { color: #AEB7C5; }
.site-footer a { display: block; color: #C8D1E0; margin: 8px 0; }
.footer-logo { margin-bottom: 12px; }
.footer-bottom { margin-top: 34px; padding-top: 18px; border-top: 1px solid rgba(255,255,255,.12); }
.footer-bottom p { margin: 0; font-size: 14px; }
@media (min-width: 720px) {
    .container { width: min(100% - 48px, 1160px); }
    .summary-grid { grid-template-columns: repeat(3, 1fr); }
    .feature-grid, .card-grid, .risk-grid { grid-template-columns: repeat(2, 1fr); }
    .process-steps { grid-template-columns: repeat(2, 1fr); }
    .policy-points, .protocol-grid { grid-template-columns: repeat(3, 1fr); }
}
@media (min-width: 980px) {
    .mobile-nav-toggle { display: none; }
    .responsive-nav {
        position: static;
        display: flex;
        flex-direction: row;
        align-items: center;
        gap: 2px;
        padding: 0;
        border: 0;
        box-shadow: none;
        background: transparent;
    }
    .responsive-nav a { padding: 8px 11px; }
    .hero-grid { grid-template-columns: 1.05fr .95fr; }
    .vpn-lab-hero { padding: 82px 0 92px; }
    .vpn-connection-section, .global-nodes-section, .high-speed-section, .multi-device-section { grid-template-columns: 1fr 1fr; }
    .high-speed-section .visual-card { order: -1; }
    .privacy-protection-section { grid-template-columns: .86fr 1.14fr; }
    .risk-grid { grid-template-columns: repeat(4, 1fr); }
    .process-steps { grid-template-columns: repeat(3, 1fr); }
    .page-layout { grid-template-columns: minmax(0, 1fr) 320px; align-items: start; }
    .article-content { padding: 36px; }
    .footer-grid { grid-template-columns: 1.4fr repeat(3, 1fr); }
}
@media (max-width: 520px) {
    .download-btn { width: 100%; }
    .hero-actions .download-btn { width: auto; min-width: 180px; }
    .float-card { position: static; margin: 10px 6px 0 0; }
    .hero-visual { min-height: auto; }
    .product-panel { padding: 16px; }
    .section { padding: 48px 0; }
    .article-content, .no-log-policy-section, .encryption-protocol-section, .safety-panel { padding: 22px; }
}