:root {
  color-scheme: light dark;
  --bg: #ffffff;
  --surface: #f5f5f7;
  --text: #1d1d1f;
  --muted: #6e6e73;
  --line: #d2d2d7;
  --link: #06c;
  --notice: #fff8e7;
  --notice-text: #6b4b00;
  --content: 980px;
}
@media (prefers-color-scheme: dark) {
  :root { --bg: #000; --surface: #1d1d1f; --text: #f5f5f7; --muted: #a1a1a6; --line: #424245; --link: #2997ff; --notice: #2c250f; --notice-text: #ffd77a; }
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; min-width: 320px; background: var(--bg); color: var(--text); font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "SF Pro Display", "PingFang SC", "Helvetica Neue", Arial, sans-serif; font-size: 17px; line-height: 1.58; -webkit-font-smoothing: antialiased; }
a { color: var(--link); text-decoration: none; }
a:hover { text-decoration: underline; }
[hidden] { display: none !important; }
.localized, [data-lang] { display: none; }
html[data-language="en"] [data-lang="en"], html[data-language="zh-Hans"] [data-lang="zh-Hans"], html[data-language="zh-Hant"] [data-lang="zh-Hant"], html[data-language="ja"] [data-lang="ja"], html[data-language="ko"] [data-lang="ko"], html[data-language="es"] [data-lang="es"], html[data-language="fr"] [data-lang="fr"], html[data-language="de"] [data-lang="de"], html[data-language="pt-BR"] [data-lang="pt-BR"] { display: revert; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0; }
.shell { width: min(calc(100% - 40px), var(--content)); margin: 0 auto; }
.site-header { width: min(calc(100% - 40px), 1080px); min-height: 52px; margin: 0 auto; display: flex; align-items: center; gap: 24px; border-bottom: 1px solid var(--line); }
.brand { display: inline-flex; align-items: center; gap: 9px; color: var(--text); font-weight: 650; letter-spacing: -0.02em; text-decoration: none; }
.brand:hover { text-decoration: none; }
.brand-mark { width: 24px; height: 24px; display: grid; place-items: center; border-radius: 7px; color: #fff; background: var(--text); font-size: 13px; font-weight: 760; }
@media (prefers-color-scheme: dark) { .brand-mark { color: #000; } }
.desktop-nav { display: flex; align-items: center; gap: 26px; margin-left: auto; }
.desktop-nav a, .mobile-nav a { color: var(--muted); font-size: 13px; white-space: nowrap; }
.desktop-nav a[aria-current="page"], .mobile-nav a[aria-current="page"] { color: var(--text); }
.language-picker { min-width: 104px; }
.language-picker select { width: 100%; min-height: 34px; padding: 0 24px 0 8px; border: 1px solid var(--line); border-radius: 9px; color: var(--text); background: var(--bg); font: inherit; font-size: 14px; }
.mobile-nav { display: none; }
.setup-notice { margin: 16px auto 0; padding: 10px 14px; border-radius: 10px; background: var(--notice); color: var(--notice-text); font-size: 14px; }
.hero { padding: clamp(88px, 14vw, 168px) 0 clamp(80px, 11vw, 132px); text-align: center; }
.eyebrow { margin: 0 0 10px; color: var(--muted); font-size: 16px; font-weight: 600; }
h1, h2, h3 { margin-top: 0; letter-spacing: -0.035em; line-height: 1.1; }
h1 { margin-bottom: 0; font-size: clamp(48px, 9vw, 88px); font-weight: 700; }
h2 { margin-bottom: 14px; font-size: clamp(30px, 5vw, 48px); font-weight: 680; }
h3 { margin-bottom: 8px; font-size: 21px; font-weight: 650; }
.hero-copy { max-width: 720px; margin: 22px auto 0; color: var(--muted); font-size: clamp(20px, 3.5vw, 28px); line-height: 1.35; letter-spacing: -0.02em; }
.hero-actions { display: flex; justify-content: center; flex-wrap: wrap; gap: 12px 24px; margin-top: 32px; }
.button { min-height: 44px; display: inline-flex; align-items: center; justify-content: center; font-size: 17px; }
.button::after { content: " ›"; padding-left: 4px; }
.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px; margin-bottom: 110px; background: var(--line); border: 1px solid var(--line); }
.feature-card { padding: 34px 30px; background: var(--bg); }
.feature-icon { margin-bottom: 30px; color: var(--muted); font-size: 18px; font-weight: 700; }
.feature-card p { margin: 0; color: var(--muted); font-size: 16px; }
.page-hero { padding: clamp(72px, 10vw, 120px) 0 56px; border-bottom: 1px solid var(--line); }
.page-hero h1 { font-size: clamp(44px, 7vw, 72px); }
.page-hero > p { max-width: 720px; margin: 18px 0 0; color: var(--muted); font-size: 21px; line-height: 1.4; }
.page-meta { margin-top: 20px; color: var(--muted); font-size: 14px; }
.content-grid { display: grid; grid-template-columns: minmax(0, 1fr) 220px; gap: 64px; align-items: start; padding: 64px 0 110px; }
.content-grid.single { grid-template-columns: minmax(0, 820px); }
.article { min-width: 0; }
.article section { padding: 36px 0; border-top: 1px solid var(--line); scroll-margin-top: 80px; }
.article section:first-child { padding-top: 0; border-top: 0; }
.article h2 { font-size: clamp(28px, 4vw, 38px); }
.article h3 { margin-top: 28px; }
.article p, .article li { color: var(--muted); }
.article strong { color: var(--text); }
.article ul, .article ol { padding-left: 1.25em; }
.article li + li { margin-top: 8px; }
.toc { position: sticky; top: 24px; padding-left: 18px; border-left: 1px solid var(--line); }
.toc strong { display: block; margin-bottom: 8px; font-size: 13px; }
.toc a { display: block; padding: 5px 0; color: var(--muted); font-size: 13px; }
.policy-card { margin: 24px 0; padding: 22px 24px; background: var(--surface); }
.policy-card strong { display: block; margin-bottom: 5px; }
.policy-card p { margin: 0; color: var(--muted); }
.data-table { width: 100%; margin: 22px 0; border-collapse: collapse; font-size: 15px; }
.data-table th, .data-table td { padding: 14px 10px; text-align: left; vertical-align: top; border-bottom: 1px solid var(--line); }
.data-table th { color: var(--text); }
.data-table td { color: var(--muted); }
.contact-card { margin: 56px 0 40px; padding: 36px; background: var(--surface); }
.contact-card-grid { display: grid; grid-template-columns: 1.25fr .75fr; gap: 44px; align-items: center; }
.contact-details { padding-left: 24px; border-left: 1px solid var(--line); }
.contact-details p { margin: 4px 0; overflow-wrap: anywhere; }
.faq-list { margin: 30px 0 90px; border-top: 1px solid var(--line); }
.faq-list details { border-bottom: 1px solid var(--line); }
.faq-list summary { cursor: pointer; list-style: none; padding: 22px 40px 22px 0; position: relative; font-weight: 620; }
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list summary::after { content: "+"; position: absolute; right: 4px; top: 18px; color: var(--muted); font-size: 22px; font-weight: 400; }
.faq-list details[open] summary::after { content: "–"; }
.faq-answer { padding: 0 44px 24px 0; color: var(--muted); }
.steps { counter-reset: step; list-style: none; padding: 0 !important; }
.steps li { counter-increment: step; position: relative; padding: 2px 0 28px 46px; }
.steps li::before { content: counter(step); position: absolute; left: 0; top: 0; width: 30px; height: 30px; display: grid; place-items: center; border: 1px solid var(--line); border-radius: 50%; color: var(--text); font-size: 14px; font-weight: 650; }
.callout { padding: 18px 20px; border-left: 3px solid var(--text); background: var(--surface); }
.site-footer { width: min(calc(100% - 40px), 1080px); margin: 0 auto; padding: 34px 0 30px; display: grid; grid-template-columns: 1fr auto; gap: 24px 40px; border-top: 1px solid var(--line); }
.site-footer p { margin: 4px 0 0; color: var(--muted); font-size: 13px; }
.footer-links { display: flex; flex-wrap: wrap; gap: 8px 20px; justify-content: flex-end; }
.footer-links a { color: var(--muted); font-size: 13px; }
.copyright { grid-column: 1 / -1; padding-top: 12px; }
@media (max-width: 820px) {
  .desktop-nav { display: none; }
  .language-picker { margin-left: auto; }
  .mobile-nav { width: min(calc(100% - 40px), 1080px); margin: 0 auto; padding: 10px 0; display: flex; gap: 20px; overflow-x: auto; border-bottom: 1px solid var(--line); scrollbar-width: none; }
  .mobile-nav a { font-size: 14px; }
  .mobile-nav::-webkit-scrollbar { display: none; }
  .content-grid { grid-template-columns: 1fr; }
  .toc { display: none; }
  .contact-card-grid { grid-template-columns: 1fr; }
  .contact-details { padding: 20px 0 0; border-left: 0; border-top: 1px solid var(--line); }
}
@media (max-width: 620px) {
  body { font-size: 16px; }
  .shell, .site-header, .mobile-nav, .site-footer { width: min(calc(100% - 28px), var(--content)); }
  .hero { padding-top: 72px; }
  .hero-actions { flex-direction: column; }
  .feature-grid { grid-template-columns: 1fr; }
  .page-hero { padding-top: 58px; }
  .content-grid { padding-top: 44px; }
  .data-table { display: block; overflow-x: auto; }
  .contact-card { margin-top: 40px; padding: 24px; }
  .site-footer { grid-template-columns: 1fr; }
  .footer-links { justify-content: flex-start; }
  .copyright { grid-column: 1; }
}
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }
@media print { .site-header, .mobile-nav, .site-footer, .setup-notice, .toc { display: none !important; } body { background: white; color: black; } .shell { width: 100%; } .content-grid { display: block; } }