/* Mark reader — content-first, follows system light/dark via color-scheme */
:root {
  --bg: #ffffff;
  --fg: #1a1a1a;
  --muted: #555;
  --line: #e2e2e2;
  --accent: #0b57d0;
  --code-bg: #f5f5f5;
  --table-stripe: #f7f7f7;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111418;
    --fg: #d8dee6;
    --muted: #9aa4b0;
    --line: #2a3038;
    --accent: #7cb0ff;
    --code-bg: #1b2027;
    --table-stripe: #181d23;
  }
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 16px/1.75 -apple-system, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
  -webkit-font-smoothing: antialiased;
}
header.site {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 8px 20px;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}
.brand { font-weight: 700; text-decoration: none; color: var(--fg); white-space: nowrap; }
nav.chapters {
  display: flex;
  gap: 4px;
  overflow-x: auto;
  scrollbar-width: thin;
}
nav.chapters a {
  color: var(--muted);
  text-decoration: none;
  padding: 4px 10px;
  border-radius: 999px;
  white-space: nowrap;
  font-size: 14px;
}
nav.chapters a:hover { color: var(--fg); background: var(--code-bg); }
nav.chapters a.active { color: var(--accent); background: color-mix(in srgb, var(--accent) 12%, transparent); font-weight: 600; }

main {
  max-width: 860px;
  margin: 0 auto;
  padding: 32px 24px 80px;
}

/* Markdown content */
main h1 { font-size: 1.9em; line-height: 1.3; margin: 0 0 0.4em; }
main h2 {
  font-size: 1.45em;
  margin: 1.8em 0 0.6em;
  padding-bottom: 0.25em;
  border-bottom: 1px solid var(--line);
}
main h3 { font-size: 1.2em; margin: 1.5em 0 0.5em; }
main h4, main h5, main h6 { font-size: 1.05em; margin: 1.3em 0 0.4em; }
main p, main ul, main ol, main blockquote, main table { margin: 0.6em 0 1.1em; }
main li { margin: 0.25em 0; }
main a { color: var(--accent); text-decoration: none; }
main a:hover { text-decoration: underline; }
main code {
  font-family: ui-monospace, "Cascadia Code", Consolas, monospace;
  font-size: 0.9em;
  background: var(--code-bg);
  padding: 0.15em 0.4em;
  border-radius: 4px;
}
main pre {
  background: var(--code-bg);
  padding: 14px 16px;
  border-radius: 8px;
  overflow-x: auto;
  line-height: 1.6;
}
main pre code { background: none; padding: 0; font-size: 0.88em; }
main blockquote {
  margin-left: 0;
  padding: 2px 0 2px 16px;
  border-left: 3px solid var(--line);
  color: var(--muted);
}
main img { max-width: 100%; }
main hr { border: none; border-top: 1px solid var(--line); margin: 2em 0; }

/* Tables */
main table {
  border-collapse: collapse;
  width: 100%;
  font-size: 0.95em;
  display: block;
  overflow-x: auto;
}
main th, main td {
  border: 1px solid var(--line);
  padding: 6px 12px;
  text-align: left;
  vertical-align: top;
}
main th { background: var(--table-stripe); font-weight: 600; }
main tr:nth-child(even) td { background: var(--table-stripe); }

/* Heading anchors */
main h1[id], main h2[id], main h3[id], main h4[id], main h5[id], main h6[id] {
  scroll-margin-top: 60px;
}

footer { text-align: center; padding: 0 0 48px; }
footer a { color: var(--muted); text-decoration: none; font-size: 14px; }
footer a:hover { color: var(--accent); }

/* Index */
main.index { max-width: 760px; }
ul.doc-list { padding-left: 4px; list-style: none; }
ul.doc-list li { margin: 0.4em 0; }
ul.doc-list a { font-size: 1.05em; }