:root {
  --bg: #eef1ec;
  --bg2: #e7ece7;
  --panel: #f8faf7;
  --ink: #19231d;
  --ink2: #4a564e;
  --ink3: #5e6b62;
  --line: #d2dad3;
  --accent: #315c46;
  --accent-hover: #284b3a;
  --gold: #8a6a3a;
  --serif: "Noto Serif SC", "Songti SC", "Source Han Serif SC", Georgia, serif;
  --sans: "Segoe UI", system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--accent); text-underline-offset: 3px; }
a:hover { color: var(--accent-hover); }
::selection { background: #d7e4db; color: var(--ink); }

.top {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 14px 28px;
  background: rgba(248, 250, 247, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
}
.brand {
  display: flex;
  align-items: baseline;
  gap: 10px;
  color: inherit;
  text-decoration: none;
}
.brand-mark {
  font-family: var(--serif);
  font-weight: 700;
  letter-spacing: 0.08em;
  font-size: 15px;
}
.brand-page {
  color: var(--ink3);
  font-size: 13px;
}
.brand-page::before { content: "·"; margin-right: 10px; color: var(--line); }
.top-nav { display: flex; gap: 8px; flex-wrap: wrap; }
.top-nav a {
  color: var(--ink2);
  text-decoration: none;
  font-size: 13px;
  padding: 6px 10px;
  border: 1px solid transparent;
}
.top-nav a:hover,
.top-nav a.is-here {
  color: var(--accent);
  border-color: var(--line);
  background: var(--panel);
}

.wrap {
  max-width: 760px;
  margin: 0 auto;
  padding: 56px 28px 96px;
}
.kicker {
  color: var(--gold);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  margin-bottom: 12px;
}
h1 {
  font-family: var(--serif);
  font-size: clamp(32px, 5vw, 44px);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.02em;
  text-wrap: balance;
}
.lede {
  margin-top: 16px;
  color: var(--ink2);
  font-size: 17px;
  max-width: 62ch;
  text-wrap: pretty;
}
.meta {
  margin-top: 22px;
  padding: 14px 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 10px 24px;
  font-size: 13px;
  color: var(--ink2);
}
.meta b { display: block; color: var(--ink3); font-weight: 600; font-size: 11px; letter-spacing: 0.08em; text-transform: uppercase; margin-bottom: 2px; }
.lang-jump {
  display: flex;
  gap: 10px;
  margin-top: 22px;
  font-size: 13px;
}

.lang {
  margin-top: 56px;
}
.lang + .lang {
  margin-top: 80px;
  padding-top: 56px;
  border-top: 1px solid var(--line);
}
.lang h2.lang-title {
  font-family: var(--serif);
  font-size: 22px;
  margin-bottom: 28px;
  color: var(--accent);
}

.doc h2 {
  font-family: var(--serif);
  font-size: 22px;
  margin: 40px 0 12px;
  scroll-margin-top: 80px;
}
.doc h3 {
  font-size: 16px;
  margin: 22px 0 8px;
}
.doc p, .doc li { color: var(--ink); max-width: 68ch; }
.doc p { margin: 0 0 12px; }
.doc ul, .doc ol { margin: 0 0 14px 1.2em; }
.doc li { margin: 0 0 6px; }
.doc ol.redlines li { margin: 0 0 10px; }
.doc code {
  font-family: ui-monospace, "Cascadia Code", Consolas, monospace;
  font-size: 0.9em;
  background: var(--panel);
  padding: 0.1em 0.35em;
  border: 1px solid var(--line);
}
.doc .warn {
  margin: 16px 0;
  padding: 12px 14px;
  border-left: 3px solid var(--gold);
  background: var(--panel);
}
.doc table {
  width: 100%;
  border-collapse: collapse;
  margin: 12px 0 18px;
  font-size: 14px;
}
.doc th, .doc td {
  text-align: left;
  vertical-align: top;
  padding: 10px 12px;
  border-bottom: 1px solid var(--line);
}
.doc th { color: var(--ink3); font-weight: 600; font-size: 12px; letter-spacing: 0.04em; }
.doc .end {
  margin-top: 36px;
  color: var(--ink3);
  font-size: 13px;
}
.doc ol.redlines {
  margin: 12px 0 18px 1.2em;
}
.doc ol.redlines li {
  margin: 0 0 12px;
}

.foot {
  max-width: 760px;
  margin: 0 auto;
  padding: 0 28px 48px;
  display: flex;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  color: var(--ink3);
  font-size: 13px;
}
.foot a { color: inherit; }

@media (max-width: 640px) {
  .top { padding: 12px 16px; }
  .wrap { padding: 36px 16px 72px; }
  .brand-page { display: none; }
  .doc table { font-size: 13px; }
}