:root {
  color-scheme: light;
  --bg: #fbf7f0;
  --panel: #ffffff;
  --ink: #241c16;
  --muted: #6d6058;
  --line: #e8ded0;
  --accent: #e8471f;        /* the logotype's orange */
  --accent-soft: #fdeae3;
  --link: #b83a14;          /* darkened for 4.5:1 text contrast */
  --radius: 14px;
  --max: 44rem;
}
@media (prefers-color-scheme: dark) {
  :root {
    color-scheme: dark;
    --bg: #16120f;
    --panel: #1f1a16;
    --ink: #f0e8df;
    --muted: #a89a8e;
    --line: #332a23;
    --accent: #ff6a3d;
    --accent-soft: #2c1811;
    --link: #ff8a5c;
  }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.7 -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans",
    "PingFang SC", "Hiragino Sans", "Noto Sans CJK SC", Roboto, Helvetica, Arial, sans-serif;
}
a { color: var(--link); }
main { max-width: var(--max); margin: 0 auto; padding: 2rem 1.25rem 1rem; }

/* header */
.bar {
  display: flex; flex-wrap: wrap; gap: .75rem 1.5rem;
  align-items: center; justify-content: space-between;
  max-width: var(--max); margin: 0 auto; padding: 1.25rem;
}
.wordmark {
  display: inline-flex; align-items: center; gap: .5rem;
  color: var(--ink); text-decoration: none;
}
.wordmark .logo { display: block; height: 1.5rem; width: auto; }
.doclinks { display: flex; gap: 1.1rem; font-size: .92rem; }
.doclinks a { color: var(--muted); text-decoration: none; }
.doclinks a:hover { color: var(--ink); }
.doclinks a.on { color: var(--ink); font-weight: 600; }

/* home */
.home h1 { font-size: 1.9rem; line-height: 1.25; margin: .5rem 0 .75rem; letter-spacing: -.02em; }
.lead { color: var(--muted); font-size: 1.02rem; margin: 0 0 1.75rem; }
.cards { display: grid; gap: 1rem; grid-template-columns: repeat(auto-fit, minmax(15rem, 1fr)); }
.card {
  display: block; padding: 1.25rem; text-decoration: none; color: inherit;
  background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius);
}
.card:hover { border-color: var(--accent); }
.card h2 { margin: 0 0 .4rem; font-size: 1.1rem; }
.card p { margin: 0 0 .9rem; color: var(--muted); font-size: .94rem; }
.card .go { color: var(--link); font-size: .9rem; font-weight: 600; }
.contact { margin-top: 1.75rem; color: var(--muted); font-size: .94rem; }

/* document */
.doc h1 { font-size: 1.75rem; line-height: 1.25; margin: .5rem 0 .35rem; letter-spacing: -.02em; }
.updated { color: var(--muted); font-size: .88rem; margin: 0 0 1.5rem; }
.toc {
  background: var(--panel); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 1rem 1.25rem; margin-bottom: 2.25rem;
}
.toc h2 { font-size: .78rem; text-transform: uppercase; letter-spacing: .08em; color: var(--muted); margin: 0 0 .6rem; }
.toc ol { margin: 0; padding-inline-start: 1.25rem; font-size: .94rem; }
.toc li { margin: .15rem 0; }
.toc a { text-decoration: none; }
.toc a:hover { text-decoration: underline; }
.doc section { scroll-margin-top: 1.5rem; }
.doc h2 {
  display: flex; align-items: baseline; gap: .6rem;
  font-size: 1.12rem; margin: 2.25rem 0 .6rem; letter-spacing: -.01em;
}
.doc h2 .num {
  flex: none; min-width: 1.55rem; height: 1.55rem; padding: 0 .35rem;
  display: inline-flex; align-items: center; justify-content: center;
  background: var(--accent-soft); color: var(--link);
  border-radius: 7px; font-size: .8rem; font-weight: 700;
}
.doc p { margin: .7rem 0; }
.doc ul { margin: .7rem 0; padding-inline-start: 1.2rem; }
.doc li { margin: .3rem 0; }
.doc .term b { color: var(--ink); }

footer {
  max-width: var(--max); margin: 0 auto; padding: 2rem 1.25rem 3rem;
  border-top: 1px solid var(--line); color: var(--muted); font-size: .85rem;
}
.langs { display: flex; flex-wrap: wrap; gap: .35rem .85rem; margin-bottom: .9rem; }
.langs a { color: var(--muted); text-decoration: none; }
.langs a:hover { color: var(--ink); }
.langs a.on { color: var(--ink); font-weight: 600; }
footer p { margin: 0; }