:root {
  --ink: #2f3d49;
  --muted: #4b5e6e;
  --heading: #214f73;
  --accent: #176aa0;
  --accent-hover: #104b75;
  --nav: #3d607c;
  --sky: #8bbddd;
  --line: #d6e5f0;
  --wash: #f2f8fc;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  --text: 20px;
  --small: 18px;
  --title: 32px;
  --section: 24px;
  --item: 21px;
  --site-width: 1120px;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 28px; }
body { margin: 0; color: var(--ink); background: #fff; font-family: var(--sans); font-size: var(--text); line-height: 1.7; }
a { color: var(--accent); text-decoration-thickness: 1px; text-underline-offset: 4px; overflow-wrap: anywhere; }
a:hover { color: var(--accent-hover); }
a:focus-visible, summary:focus-visible, button:focus-visible { outline: 2px solid var(--accent); outline-offset: 4px; }
img { max-width: 100%; height: auto; }
::selection { background: #d9ecf9; color: var(--heading); }
h1, h2, h3 { color: var(--heading); line-height: 1.35; font-weight: 550; }
h1 { font-size: var(--title); letter-spacing: -.015em; }
h2 { font-size: var(--section); }
h3 { font-size: var(--item); }
p { margin: 0 0 1.1em; }
strong { font-weight: 600; }
.skip-link { position: absolute; top: -100px; left: 16px; z-index: 20; padding: 10px 16px; color: #fff; background: var(--accent); }
.skip-link:focus { top: 12px; color: #fff; }
.site-header { background: var(--wash); border-bottom: 1px solid var(--sky); }
.header-inner, .footer-inner, .page-shell, .home-shell { max-width: var(--site-width); margin: 0 auto; padding-left: 32px; padding-right: 32px; }
.header-inner { min-height: 82px; display: flex; align-items: center; justify-content: space-between; gap: 28px; }
.wordmark { font-size: 22px; font-weight: 500; color: var(--accent); text-decoration: none; white-space: nowrap; }
.main-nav { display: flex; align-items: center; gap: 25px; flex-wrap: wrap; }
.main-nav a { padding: 8px 0; color: var(--nav); font-size: var(--small); font-weight: 400; text-decoration: none; white-space: nowrap; }
.main-nav a:hover, .main-nav a[aria-current] { color: var(--accent); }
.main-nav a[aria-current] { text-decoration: underline; text-underline-offset: 7px; }
.site-main { min-height: 65vh; }
.page-shell, .home-shell { padding-top: 42px; padding-bottom: 64px; }
.page-heading { margin-bottom: 24px; }
.page-heading h1 { margin: 0; }
.page-description { max-width: 900px; margin: 10px 0 0; font-size: var(--small); color: var(--muted); line-height: 1.65; }
.section-nav { display: flex; flex-wrap: wrap; gap: 8px 24px; margin: 0 0 28px; font-size: var(--small); }
.section-nav a { text-decoration: none; }
.section-nav a:hover { text-decoration: underline; }
.prose { max-width: 960px; overflow-wrap: break-word; }
.prose h2 { margin: 32px 0 16px; padding-bottom: 9px; border-bottom: 1px solid var(--line); }
.prose > h2:first-child, .prose > section:first-child > h2 { margin-top: 0; }
.prose h3 { margin: 24px 0 10px; }
.prose ul, .prose ol { padding-left: 25px; margin: 0 0 24px; }
.prose li { padding-left: 3px; margin-bottom: 10px; }
.prose li > ul { margin: 10px 0; }
.prose li > ul > li { margin-bottom: 6px; }
.prose blockquote { border-left: 2px solid var(--sky); margin: 24px 0; padding: 0 20px; color: var(--muted); }
.prose blockquote p:last-child { margin: 0; }
.prose hr { border: 0; border-top: 1px solid var(--line); margin: 28px 0; }
.prose table { display: block; width: 100%; overflow-x: auto; border-collapse: collapse; margin: 24px 0; font-size: var(--small); }
.prose th, .prose td { border-bottom: 1px solid var(--line); text-align: left; padding: 12px 18px 12px 0; min-width: 160px; vertical-align: top; }
.prose th { font-weight: 550; }
.prose pre { overflow: auto; padding: 20px; background: var(--wash); font-size: var(--small); }
.prose :not(pre) > code { font-size: .95em; background: var(--wash); padding: 2px 5px; }
/* Page templates style ordinary Markdown lists; content needs no CSS classes. */
.research-page .prose > p:first-child { margin: -12px 0 28px; font-size: var(--small); color: var(--muted); }
.research-page .prose > p:first-child a { text-decoration: none; }
.research-page .prose > p:first-child a:hover { text-decoration: underline; }
.research-page .prose > h2:first-of-type { margin-top: 0; }
.research-page .prose > ul, .code-page > ul { list-style: none; margin: 0 0 32px; padding: 0; }
.research-page .prose > ul > li { margin: 0 0 24px; padding: 0; line-height: 1.65; }
.research-page .prose > ul > li:last-child { margin-bottom: 0; }
.research-page .prose > ul > li > p { margin: 0; font-size: var(--small); color: var(--muted); }
.research-page .prose > ul > li > p:first-child { margin-bottom: 5px; font-size: var(--item); line-height: 1.45; color: var(--heading); }
.research-page .prose > ul > li strong { font-weight: 550; }
.research-page .prose > ul > li > p > a { display: inline-block; margin-top: 5px; text-decoration: none; }
.research-page .prose > ul > li > p > a:hover { text-decoration: underline; }
.code-page { max-width: none; }
.code-page > ul > li { display: grid; grid-template-columns: 200px minmax(0, 1fr); column-gap: 28px; row-gap: 7px; align-items: start; padding: 16px 0 24px; margin: 0; }
.code-page > ul > li > p { grid-column: 2; margin: 0; font-size: var(--small); line-height: 1.7; }
.code-page > ul > li > p:first-child { grid-column: 1; grid-row: 1 / span 3; }
.code-page > ul > li > p:first-child > a { display: flex; align-items: center; justify-content: center; height: 156px; padding: 6px; background: #fff; border: 1px solid var(--line); border-radius: 3px; }
.code-page > ul > li > p:first-child img { display: block; width: auto; height: auto; max-width: 100%; max-height: 100%; object-fit: contain; }
.code-page > ul > li > p:first-child > a:hover { border-color: var(--accent); }
.code-page > ul > li > p:nth-child(2) { font-size: var(--item); color: var(--heading); line-height: 1.45; }
.code-page > ul > li > p:nth-child(2) strong { font-weight: 550; }
.code-page > ul > li > p > a { text-decoration: none; }
.code-page > ul > li > p > a:hover { text-decoration: underline; }
.site-footer { background: var(--wash); border-top: 1px solid var(--line); }
.footer-inner { min-height: 90px; display: flex; align-items: center; justify-content: space-between; gap: 24px; color: var(--muted); font-size: 16px; }
.footer-inner p { margin: 0; }
.footer-inner p span { padding: 0 7px; }
.footer-links { display: flex; gap: 20px; flex-wrap: wrap; }
.footer-links a { color: var(--accent); text-decoration: none; }
.footer-links a:hover { color: var(--accent); }
@media (max-width: 900px) {
  .header-inner { align-items: flex-start; padding-top: 18px; padding-bottom: 18px; gap: 14px 24px; }
  .main-nav { gap: 6px 18px; justify-content: flex-end; }
}
@media (max-width: 640px) {
  :root { --text: 18px; --small: 17px; --title: 29px; --section: 23px; --item: 20px; }
  .header-inner, .footer-inner, .page-shell, .home-shell { padding-left: 22px; padding-right: 22px; }
  .header-inner { flex-direction: column; gap: 8px; }
  .main-nav { width: 100%; justify-content: flex-start; gap: 4px 20px; }
  .page-shell, .home-shell { padding-top: 30px; padding-bottom: 48px; }
  .page-heading { margin-bottom: 22px; }
  .code-page > ul > li { grid-template-columns: 1fr; gap: 10px; }
  .code-page > ul > li > p { grid-column: 1; }
  .code-page > ul > li > p:first-child { grid-row: auto; width: 200px; max-width: 100%; margin-bottom: 6px; }
  .prose li { padding-left: 0; }
  .footer-inner { padding-top: 22px; padding-bottom: 22px; flex-direction: column; align-items: flex-start; gap: 10px; }
}
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }
@media print {
  .site-header, .site-footer, .skip-link, .section-nav { display: none; }
  .page-shell { max-width: none; padding: 0; }
  a { color: inherit; }
  .code-page > ul > li, .research-page .prose > ul > li { break-inside: avoid; }
}