:root {
  --ink: #171512;
  --ink-soft: #514b43;
  --paper: #f7f4ee;
  --white: #fff;
  --line: #dcd4c8;
  --gold: #a67a38;
  --forest: #263d35;
  --serif: "Noto Serif SC", "Songti SC", serif;
  --sans: "Noto Sans SC", "Microsoft YaHei", sans-serif;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.8;
}
a { color: inherit; text-decoration-thickness: 1px; text-underline-offset: 4px; }
.skip-link { position: fixed; left: 1rem; top: -5rem; z-index: 100; padding: .7rem 1rem; color: var(--white); background: var(--ink); }
.skip-link:focus { top: 1rem; }
.shell { width: min(1180px, calc(100% - 40px)); margin: 0 auto; }
.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  border-bottom: 1px solid rgba(23, 21, 18, .1);
  background: rgba(247, 244, 238, .94);
  backdrop-filter: blur(14px);
}
.header-inner { width: min(1240px, calc(100% - 32px)); min-height: 76px; margin: 0 auto; display: flex; align-items: center; justify-content: space-between; gap: 2rem; }
.brand { display: inline-flex; align-items: center; gap: .8rem; text-decoration: none; }
.brand-mark { display: grid; place-items: center; width: 42px; height: 42px; border: 1px solid var(--ink); border-radius: 50%; font-family: var(--serif); font-size: 1.35rem; font-weight: 900; }
.brand strong { display: block; font-family: var(--serif); letter-spacing: .12em; }
.brand small { display: block; color: var(--ink-soft); font-size: .66rem; letter-spacing: .16em; }
.desktop-nav { display: flex; align-items: center; gap: 1.2rem; }
.desktop-nav a { font-size: .9rem; text-decoration: none; }
.desktop-nav a:hover { color: var(--gold); }
.nav-phone { padding: .5rem .9rem; border: 1px solid var(--ink); border-radius: 999px; }
.mobile-nav { display: none; position: relative; }
.hero {
  position: relative;
  overflow: hidden;
  padding: 86px 0 72px;
  border-bottom: 1px solid var(--line);
  background: radial-gradient(circle at 88% 18%, rgba(166, 122, 56, .14), transparent 26rem), linear-gradient(135deg, #f9f7f2, #eee8dd);
}
.hero::after { content: "A"; position: absolute; right: 4vw; bottom: -11rem; color: rgba(23, 21, 18, .035); font-family: var(--serif); font-size: 30rem; line-height: 1; pointer-events: none; }
.hero-grid { position: relative; z-index: 1; display: grid; grid-template-columns: minmax(0, 1.35fr) minmax(300px, .65fr); gap: 72px; align-items: end; }
.eyebrow, .section-kicker { color: var(--gold); font-size: .75rem; font-weight: 700; letter-spacing: .18em; text-transform: uppercase; }
.breadcrumbs { display: flex; gap: .55rem; margin: .8rem 0 1.4rem; color: var(--ink-soft); font-size: .85rem; }
.breadcrumbs a { text-decoration: none; }
h1, h2 { font-family: var(--serif); }
h1 { max-width: 820px; margin: 0; font-size: clamp(2.55rem, 5vw, 5.4rem); font-weight: 700; letter-spacing: -.04em; line-height: 1.12; }
.direct-answer { max-width: 780px; margin: 2rem 0 0; padding-left: 1.1rem; border-left: 3px solid var(--gold); color: var(--ink-soft); font-size: 1.12rem; }
.hero-actions { display: flex; flex-wrap: wrap; gap: .8rem; margin-top: 2rem; }
.primary-button, .secondary-button { display: inline-flex; min-height: 48px; align-items: center; justify-content: center; padding: .7rem 1.25rem; border: 1px solid var(--ink); text-decoration: none; }
.primary-button { color: var(--white); background: var(--ink); }
.secondary-button { background: transparent; }
.fact-card { padding: 1.8rem; border: 1px solid rgba(23, 21, 18, .16); background: rgba(255, 255, 255, .65); box-shadow: 0 24px 80px rgba(38, 30, 18, .08); }
.fact-card-title { padding-bottom: .8rem; border-bottom: 1px solid var(--line); font-family: var(--serif); font-size: 1.25rem; font-weight: 700; }
.fact-card dl { margin: 0; }
.fact-card dl div { padding: .85rem 0; border-bottom: 1px solid var(--line); }
.fact-card dl div:last-child { border-bottom: 0; }
.fact-card dt { color: var(--ink-soft); font-size: .78rem; }
.fact-card dd { margin: .15rem 0 0; font-weight: 600; line-height: 1.55; }
.content-layout { display: grid; grid-template-columns: minmax(0, 1fr) 300px; gap: 76px; padding-top: 80px; padding-bottom: 100px; }
.content { min-width: 0; }
.section-block { display: grid; grid-template-columns: 56px minmax(0, 1fr); gap: 24px; padding: 0 0 64px; margin-bottom: 64px; border-bottom: 1px solid var(--line); }
.section-number { color: var(--gold); font-family: var(--serif); font-size: 1.3rem; }
h2 { margin: 0 0 1.1rem; font-size: clamp(1.75rem, 3vw, 2.65rem); line-height: 1.3; }
.content p { color: var(--ink-soft); }
.check-list { display: grid; gap: .8rem; margin: 1.2rem 0 0; padding: 0; list-style: none; }
.check-list li { position: relative; padding-left: 1.8rem; }
.check-list li::before { content: "—"; position: absolute; left: 0; color: var(--gold); }
.table-wrap { overflow-x: auto; margin-top: 1.5rem; border: 1px solid var(--line); background: var(--white); }
table { width: 100%; border-collapse: collapse; min-width: 600px; }
th, td { padding: .9rem 1rem; border-bottom: 1px solid var(--line); text-align: left; }
th { color: var(--white); background: var(--forest); font-size: .85rem; }
td:last-child { color: var(--gold); font-weight: 700; }
.faq-section { padding: 4rem 0 2rem; }
.faq-list { margin-top: 1.5rem; border-top: 1px solid var(--line); }
.faq-list details { border-bottom: 1px solid var(--line); }
.faq-list summary { cursor: pointer; padding: 1.2rem 2.5rem 1.2rem 0; font-family: var(--serif); font-size: 1.08rem; font-weight: 700; }
.faq-list details p { padding: 0 0 1.3rem; margin: 0; }
.source-panel { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px; margin-top: 3rem; border: 1px solid var(--line); background: var(--line); }
.source-panel > div, .source-panel > p { margin: 0; padding: 1rem; background: var(--white); }
.source-panel span { display: block; color: var(--ink-soft); font-size: .75rem; }
.source-panel p { grid-column: 1 / -1; color: var(--ink-soft); font-size: .85rem; }
.sticky-card { position: sticky; top: 108px; padding: 1.5rem; border: 1px solid var(--line); background: var(--white); }
.sticky-card h2 { font-size: 1.4rem; }
.sticky-card ul { display: grid; gap: .85rem; padding: 0; list-style: none; }
.sticky-card li { padding-bottom: .85rem; border-bottom: 1px solid var(--line); }
.sticky-card a { text-decoration: none; }
.sticky-card a:hover { color: var(--gold); }
.contact-strip { margin: 1.5rem -1.5rem -1.5rem; padding: 1.1rem 1.5rem; color: var(--white); background: var(--forest); }
.contact-strip span { display: block; font-size: .75rem; opacity: .72; }
.contact-strip a { font-family: var(--serif); font-size: 1.2rem; }
footer { padding: 48px 0; color: rgba(255,255,255,.78); background: var(--ink); }
.footer-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; }
footer strong { color: var(--white); font-family: var(--serif); font-size: 1.35rem; }
footer p { margin: .5rem 0; }
@media (max-width: 980px) {
  .desktop-nav { display: none; }
  .mobile-nav { display: block; }
  .mobile-nav summary { cursor: pointer; padding: .5rem .8rem; border: 1px solid var(--ink); list-style: none; }
  .mobile-nav > div { position: absolute; right: 0; top: 3rem; width: min(280px, calc(100vw - 32px)); padding: .8rem; border: 1px solid var(--line); background: var(--white); box-shadow: 0 18px 50px rgba(0,0,0,.12); }
  .mobile-nav a { display: block; padding: .65rem; text-decoration: none; }
  .hero-grid, .content-layout { grid-template-columns: 1fr; }
  .hero-grid { gap: 44px; }
  .content-layout { gap: 48px; }
  .sidebar { order: -1; }
  .sticky-card { position: static; }
}
@media (max-width: 640px) {
  .shell { width: min(100% - 28px, 1180px); }
  .header-inner { width: calc(100% - 28px); min-height: 68px; }
  .brand small { display: none; }
  .hero { padding: 58px 0 48px; }
  h1 { font-size: clamp(2.15rem, 12vw, 3.4rem); }
  .direct-answer { font-size: 1rem; }
  .fact-card { padding: 1.2rem; }
  .content-layout { padding-top: 52px; padding-bottom: 64px; }
  .section-block { grid-template-columns: 1fr; gap: 8px; padding-bottom: 44px; margin-bottom: 44px; }
  .source-panel { grid-template-columns: 1fr; }
  .source-panel p { grid-column: auto; }
  .footer-grid { grid-template-columns: 1fr; }
}
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }