:root {
  color-scheme: light;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
  color: #202724;
  background: #fff;
  font-synthesis: none;
  --muted: #5d6661;
  --accent: #14665e;
  --line: #d9dfe0;
}
*, *::before, *::after { box-sizing: border-box; letter-spacing: 0; }
[hidden] { display: none !important; }
body { margin: 0; font-size: 16px; line-height: 1.7; -webkit-font-smoothing: antialiased; }
a { color: var(--accent); text-underline-offset: 4px; }
a:hover { text-decoration: underline; }
:focus-visible { outline: 3px solid #176b62; outline-offset: 4px; }
.skip-link { position: absolute; top: -80px; left: 16px; padding: 10px 16px; background: #fff; z-index: 100; }
.skip-link:focus { top: 12px; }
.site-header { border-bottom: 1px solid var(--line); }
.site-header-bar, .site-main, .site-footer-inner { max-width: 1168px; margin: 0 auto; padding-inline: 32px; }
.site-header-bar { padding-block: 20px; }
.site-brand { display: flex; align-items: center; gap: 14px; }
.site-brand-mark { display: grid; place-items: center; width: 42px; height: 42px; flex-shrink: 0; border-radius: 6px; background: var(--accent); color: #fff; font-weight: 750; }
.eyebrow { margin: 0; font-size: 13px; color: var(--muted); }
.site-title { margin: 0; font-size: 23px; font-weight: 700; line-height: 1.4; }
.hub-intro { padding: 36px 0 28px; }
.hub-intro h2 { font-size: 36px; line-height: 1.4; margin: 6px 0 14px; }
.hub-intro > p:last-of-type { margin: 0; color: var(--muted); }
.continue-reading { display: inline-flex; align-items: center; min-height: 44px; margin-top: 14px; font-size: 14px; font-weight: 600; }
.hub-toolbar { display: flex; align-items: center; justify-content: space-between; gap: 16px; padding: 18px 0; border-top: 1px solid var(--line); }
.hub-toolbar > p { margin: 0; font-size: 14px; color: var(--muted); }
.hub-search { display: flex; align-items: center; gap: 10px; }
.hub-search label { font-size: 14px; color: var(--muted); }
.hub-search input { width: 260px; max-width: 100%; min-height: 42px; padding: 8px 12px; font: inherit; font-size: 14px; border: 1px solid #abb9b0; border-radius: 6px; color: inherit; background: #fff; }
.hub-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); column-gap: 40px; }
.hub-card { display: grid; grid-template-columns: 42px minmax(0, 1fr); gap: 16px; padding: 26px 0; border-top: 1px solid var(--line); }
.hub-card-num { font-size: 14px; font-weight: 650; font-variant-numeric: tabular-nums; color: var(--accent); border-top: 3px solid var(--accent); padding-top: 5px; align-self: start; }
.hub-card:nth-child(4n + 2) .hub-card-num { border-color: #697baf; color: #485985; }
.hub-card:nth-child(4n + 3) .hub-card-num { border-color: #b2773e; color: #835326; }
.hub-card:nth-child(4n + 4) .hub-card-num { border-color: #8b7398; color: #745b82; }
.hub-card h3 { margin: 0 0 8px; font-size: 21px; line-height: 1.5; }
.hub-card h3 a { color: inherit; text-decoration: none; }
.hub-card h3 a:hover { color: var(--accent); text-decoration: underline; }
.hub-card-question { margin: 0 0 10px; font-size: 17px; line-height: 1.8; color: #414c46; }
.hub-card-meta { margin: 0; font-size: 14px; color: var(--muted); }
.hub-card-actions { display: flex; gap: 20px; flex-wrap: wrap; margin-top: 12px; }
.hub-card-actions a { display: inline-flex; align-items: center; gap: 8px; min-height: 40px; font-size: 14px; text-decoration: none; font-weight: 600; }
.hub-card-actions a + a { color: var(--muted); font-weight: 500; }
.hub-card-actions a:hover { text-decoration: underline; }
.search-empty { padding: 32px 0; color: var(--muted); }
.site-footer { border-top: 1px solid var(--line); margin-top: 24px; padding: 24px 0; background: #f6f8f7; }
.footer-copy { margin: 0; color: var(--muted); font-size: 13px; }
@media (max-width: 720px) {
  .site-header-bar, .site-main, .site-footer-inner { padding-inline: 20px; }
  .site-header-bar { padding-block: 16px; }
  .hub-intro { padding-block: 28px 22px; }
  .hub-intro h2 { font-size: 26px; }
  .hub-grid { grid-template-columns: minmax(0, 1fr); }
  .hub-card { gap: 14px; padding-block: 22px; }
  .hub-toolbar { align-items: start; flex-direction: column; gap: 12px; }
  .hub-search { width: 100%; }
  .hub-search input { flex: 1; width: 0; min-width: 0; }
  .hub-card-actions a { min-height: 44px; }
}