:root {
    --gradient: linear-gradient(90deg, #3558F2 0%, #7B4EF1 50%, #B84DDA 100%);
    --blue: #2980FE;
    --blue-dark: #1768E8;
    --text: #1f2937;
    --muted: #657083;
    --light: #f6f8fc;
    --line: #e6ebf2;
    --panel: #ffffff;
    --radius: 28px;
    --shadow: 0 18px 50px rgba(28, 47, 92, .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(1120px, calc(100% - 32px)); margin: 0 auto; }
.site-header {
    position: sticky;
    top: 0;
    z-index: 50;
    background: rgba(255,255,255,.92);
    border-bottom: 1px solid rgba(230,235,242,.85);
    backdrop-filter: blur(16px);
}
.header-inner { min-height: 70px; display: flex; align-items: center; justify-content: space-between; gap: 18px; }
.logo { display: inline-flex; align-items: center; gap: 10px; font-weight: 800; font-size: 18px; color: #172033; }
.logo img { width: 40px; height: 40px; border-radius: 12px; object-fit: cover; }
.nav-toggle { display: none; }
.nav-button { width: 44px; height: 44px; display: grid; place-items: center; gap: 4px; padding: 10px; border: 1px solid var(--line); border-radius: 14px; background: #fff; }
.nav-button span { width: 20px; height: 2px; display: block; background: #27344d; border-radius: 99px; }
.site-nav {
    position: absolute;
    left: 16px;
    right: 16px;
    top: 76px;
    display: none;
    flex-direction: column;
    padding: 14px;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 22px;
    box-shadow: var(--shadow);
}
.site-nav a { padding: 12px 14px; border-radius: 14px; color: #475569; font-weight: 650; }
.site-nav a.active, .site-nav a:hover { color: var(--blue); background: #eef5ff; }
.nav-toggle:checked ~ .site-nav { display: flex; }
.download-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 0 24px;
    border-radius: 999px;
    background: #2980FE;
    color: #fff;
    font-weight: 800;
    letter-spacing: .02em;
    box-shadow: 0 12px 28px rgba(41,128,254,.24);
    transition: transform .2s ease, background .2s ease, box-shadow .2s ease;
}
.download-btn:hover { background: #1768E8; transform: translateY(-2px); box-shadow: 0 16px 34px rgba(23,104,232,.28); }
.vpn-saas-hero {
    position: relative;
    padding: 64px 0 58px;
    color: #fff;
    background: var(--gradient);
    overflow: hidden;
}
.vpn-saas-hero::after {
    content: "";
    position: absolute;
    inset: auto -10% -120px -10%;
    height: 220px;
    background: #fff;
    transform: skewY(-5deg);
    transform-origin: 0 0;
}
.hero-grid { position: relative; z-index: 1; display: grid; gap: 38px; align-items: center; }
.hero-copy h1 { margin: 0 0 18px; font-size: clamp(36px, 8vw, 68px); line-height: 1.06; letter-spacing: -.05em; }
.hero-copy p { margin: 0 0 24px; max-width: 650px; color: rgba(255,255,255,.88); font-size: 17px; }
.hero-tags, .floating-tags { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 22px; }
.hero-tags span, .floating-tags span { display: inline-flex; align-items: center; gap: 6px; padding: 8px 12px; border-radius: 999px; background: rgba(255,255,255,.16); border: 1px solid rgba(255,255,255,.22); font-size: 13px; font-weight: 700; }
.hero-visual { position: relative; min-height: 320px; display: grid; place-items: center; }
.hero-card { position: relative; width: min(420px, 92%); padding: 18px; border-radius: 36px; background: rgba(255,255,255,.22); border: 1px solid rgba(255,255,255,.28); box-shadow: 0 28px 80px rgba(19,30,74,.24); backdrop-filter: blur(14px); }
.hero-card img { width: 100%; border-radius: 26px; background: #fff; }
.floating-note { position: absolute; z-index: 2; padding: 12px 14px; border-radius: 18px; background: #fff; color: #172033; font-weight: 800; box-shadow: 0 18px 40px rgba(21,37,85,.18); font-size: 13px; }
.note-one { top: 6%; left: 2%; }
.note-two { right: 0; top: 30%; }
.note-three { bottom: 16%; left: 6%; }
.section { padding: 66px 0; }
.section-soft { background: var(--light); }
.section-title { max-width: 760px; margin: 0 0 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: 6px 11px; border-radius: 999px; background: #eef5ff; color: var(--blue); font-weight: 800; font-size: 13px; }
h1, h2, h3 { line-height: 1.25; color: #111827; }
h2 { margin: 12px 0 12px; font-size: clamp(28px, 5vw, 44px); letter-spacing: -.03em; }
h3 { margin: 0 0 10px; font-size: 21px; }
p { color: var(--muted); }
.product-highlights { display: grid; gap: 16px; }
.highlight-card, .plain-card, .risk-card, .faq-item, .step-card, .info-card {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 24px;
    box-shadow: 0 14px 34px rgba(31,45,78,.06);
}
.highlight-card { padding: 22px; }
.highlight-card .tag { display: inline-block; margin-bottom: 12px; padding: 5px 10px; border-radius: 999px; color: var(--blue); background: #edf5ff; font-size: 12px; font-weight: 900; }
.text-link { color: var(--blue); font-weight: 800; }
.feature-panel { display: grid; gap: 26px; align-items: center; padding: 24px; border-radius: 32px; background: #fff; border: 1px solid var(--line); box-shadow: var(--shadow); }
.feature-panel.reverse .feature-media { order: -1; }
.feature-media { border-radius: 28px; background: linear-gradient(180deg, #f6f9ff 0%, #eef4ff 100%); padding: 18px; overflow: hidden; }
.feature-media img { border-radius: 22px; margin: 0 auto; }
.feature-list { display: grid; gap: 12px; margin: 20px 0 0; padding: 0; list-style: none; }
.feature-list li { padding: 12px 14px; border-radius: 16px; background: #f8fafc; border: 1px solid #edf1f7; color: #48566b; }
.high-speed-section .feature-panel { background: linear-gradient(135deg, #ffffff 0%, #f4f8ff 100%); }
.global-nodes-section .node-grid { display: grid; gap: 18px; }
.node-card { padding: 20px; border-radius: 24px; border: 1px solid var(--line); background: #fff; }
.privacy-protection-section .privacy-grid, .no-log-policy-section .policy-grid, .multi-device-section .device-grid, .encryption-protocol-section .protocol-grid { display: grid; gap: 18px; }
.privacy-shell { padding: 24px; border-radius: 34px; background: #fff; border: 1px solid var(--line); box-shadow: var(--shadow); }
.safety-panel { padding: 24px; border-radius: 32px; background: linear-gradient(135deg, #f8fbff 0%, #ffffff 100%); border: 1px solid var(--line); }
.process-steps { display: grid; gap: 16px; counter-reset: step; }
.step-card { position: relative; padding: 22px; }
.step-card .number { width: 38px; height: 38px; display: inline-grid; place-items: center; margin-bottom: 14px; border-radius: 14px; background: var(--blue); color: #fff; font-weight: 900; }
.risk-grid { display: grid; gap: 16px; }
.risk-card { padding: 20px; border-left: 4px solid var(--blue); }
.risk-card strong { display: block; margin-bottom: 6px; color: #172033; }
.faq-list { display: grid; gap: 14px; }
.faq-item { padding: 20px; }
.faq-item h3 { font-size: 18px; }
.cta-section { padding: 68px 0; color: #fff; background: var(--gradient); text-align: center; }
.cta-section h2 { color: #fff; }
.cta-section p { max-width: 680px; margin: 0 auto 24px; color: rgba(255,255,255,.86); }
.page-hero { padding: 58px 0 36px; background: linear-gradient(180deg, #f4f7ff 0%, #fff 100%); }
.page-hero h1 { margin: 16px 0 14px; max-width: 820px; font-size: clamp(34px, 7vw, 56px); letter-spacing: -.04em; }
.page-hero p { max-width: 820px; font-size: 17px; }
.page-layout { display: grid; gap: 26px; padding: 42px 0 70px; }
.article-card { padding: 22px; border-radius: 28px; background: #fff; border: 1px solid var(--line); box-shadow: 0 16px 42px rgba(24,45,87,.06); }
.article-card h2 { font-size: 28px; }
.article-card p { margin: 0 0 16px; }
.side-panel { padding: 22px; border-radius: 28px; background: #f8fafc; border: 1px solid var(--line); height: fit-content; }
.side-panel ul, .check-list { margin: 0; padding: 0; list-style: none; display: grid; gap: 12px; }
.side-panel li, .check-list li { padding: 12px 14px; border-radius: 16px; background: #fff; border: 1px solid #edf1f7; color: #4b5563; }
.download-center { display: grid; gap: 22px; align-items: center; padding: 26px; border-radius: 34px; background: #fff; border: 1px solid var(--line); box-shadow: var(--shadow); }
.download-steps { display: grid; gap: 14px; margin-top: 24px; }
.download-step { padding: 18px; border-radius: 22px; background: #f8fafc; border: 1px solid var(--line); }
.about-grid { display: grid; gap: 18px; }
.site-footer { background: #101827; color: #d9e2f2; padding: 54px 0 22px; }
.site-footer p, .site-footer span { color: #a8b5ca; }
.footer-grid { display: grid; gap: 28px; }
.footer-brand { display: flex; align-items: center; gap: 10px; color: #fff; font-size: 18px; }
.footer-brand img { width: 38px; height: 38px; border-radius: 12px; object-fit: cover; }
.site-footer h3 { color: #fff; font-size: 16px; margin-bottom: 12px; }
.site-footer a { display: block; color: #a8b5ca; margin: 8px 0; }
.site-footer a:hover { color: #fff; }
.footer-bottom { display: flex; flex-direction: column; gap: 8px; margin-top: 34px; padding-top: 20px; border-top: 1px solid rgba(255,255,255,.1); font-size: 13px; }
@media (min-width: 720px) {
    .container { width: min(1120px, calc(100% - 48px)); }
    .product-highlights, .privacy-protection-section .privacy-grid, .policy-grid, .device-grid, .protocol-grid, .about-grid { grid-template-columns: repeat(2, 1fr); }
    .process-steps, .risk-grid, .download-steps { grid-template-columns: repeat(2, 1fr); }
    .footer-grid { grid-template-columns: 1.4fr 1fr 1fr 1fr; }
    .footer-bottom { flex-direction: row; justify-content: space-between; }
}
@media (min-width: 960px) {
    .nav-button { display: none; }
    .site-nav { position: static; display: flex; flex-direction: row; align-items: center; gap: 4px; padding: 0; border: 0; box-shadow: none; background: transparent; }
    .site-nav a { padding: 9px 12px; font-size: 14px; }
    .hero-grid { grid-template-columns: 1.02fr .98fr; }
    .vpn-saas-hero { padding: 86px 0 96px; }
    .product-highlights { grid-template-columns: repeat(4, 1fr); }
    .feature-panel { grid-template-columns: 1fr .92fr; padding: 34px; }
    .feature-panel.reverse .feature-media { order: 2; }
    .global-nodes-section .node-grid { grid-template-columns: .9fr 1.1fr; align-items: center; }
    .privacy-protection-section .privacy-grid, .policy-grid, .device-grid, .protocol-grid { grid-template-columns: repeat(3, 1fr); }
    .process-steps { grid-template-columns: repeat(3, 1fr); }
    .risk-grid { grid-template-columns: repeat(4, 1fr); }
    .page-layout { grid-template-columns: minmax(0, 1fr) 320px; }
    .download-center { grid-template-columns: 1fr .9fr; padding: 34px; }
    .about-grid { grid-template-columns: repeat(3, 1fr); }
}
@media (max-width: 480px) {
    .container { width: min(100% - 24px, 1120px); }
    .section { padding: 48px 0; }
    .hero-copy h1 { font-size: 38px; }
    .download-btn { width: 100%; min-height: 52px; }
    .hero-tags span, .floating-tags span { font-size: 12px; }
    .floating-note { position: static; margin-top: 10px; width: fit-content; }
    .hero-visual { min-height: auto; }
    .page-hero { padding-top: 42px; }
}