:root {
  --bg: #fbfaf8;
  --fg: #1d1d1f;
  --muted: #6b6b70;
  --line: #e4e1dc;
  --accent: #8a5a2b;
  --card: #ffffff;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #141413;
    --fg: #f2f0ec;
    --muted: #a3a19c;
    --line: #33322f;
    --accent: #d3a06a;
    --card: #1c1b19;
  }
}

* { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 17px/1.7 -apple-system, BlinkMacSystemFont, "SF Pro Text", "Helvetica Neue",
    "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

main {
  max-width: 720px;
  margin: 0 auto;
  padding: 48px 20px 96px;
}

nav {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
  align-items: baseline;
  margin-bottom: 40px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--line);
}

nav .brand {
  font-weight: 600;
  letter-spacing: 0.02em;
  margin-right: auto;
}

nav a {
  color: var(--muted);
  text-decoration: none;
}

nav a:hover,
nav a[aria-current="page"] {
  color: var(--accent);
}

h1 {
  font-size: 34px;
  line-height: 1.2;
  letter-spacing: -0.01em;
  margin: 0 0 8px;
}

h2 {
  font-size: 21px;
  line-height: 1.3;
  margin: 40px 0 12px;
}

h3 {
  font-size: 17px;
  margin: 24px 0 8px;
}

p, ul, ol { margin: 0 0 14px; }

ul, ol { padding-left: 22px; }

li { margin-bottom: 6px; }

.meta {
  color: var(--muted);
  font-size: 15px;
  margin-bottom: 32px;
}

.summary {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 18px 20px;
  margin: 24px 0 8px;
}

.summary p:last-child { margin-bottom: 0; }

a { color: var(--accent); }

.lang-divider {
  margin: 64px 0 40px;
  border: 0;
  border-top: 1px solid var(--line);
}

footer {
  margin-top: 64px;
  padding-top: 16px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 14px;
}

footer a { color: var(--muted); }

@media (max-width: 480px) {
  main { padding: 32px 16px 64px; }
  h1 { font-size: 28px; }
  h2 { font-size: 19px; }
}