:root {
  --bg: #ffffff;
  --fg: #1c1e21;
  --muted: #5c6470;
  --line: #e3e5e8;
  --accent: #5865f2;
  --card: #f7f8fa;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #1a1b1e;
    --fg: #e6e8eb;
    --muted: #9aa3af;
    --line: #2f3136;
    --accent: #8b93f8;
    --card: #232428;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  padding: 3rem 1.25rem 6rem;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans TC",
    "PingFang TC", "Microsoft JhengHei", Roboto, sans-serif;
  line-height: 1.75;
  font-size: 16px;
}

main { max-width: 46rem; margin: 0 auto; }

h1 {
  font-size: 1.9rem;
  line-height: 1.3;
  margin: 0 0 .5rem;
  letter-spacing: -.01em;
}

h2 {
  font-size: 1.35rem;
  margin: 3rem 0 .75rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--line);
  letter-spacing: -.01em;
}

h3 { font-size: 1.05rem; margin: 2rem 0 .5rem; }

.updated { color: var(--muted); font-size: .9rem; margin: 0 0 2.5rem; }

.lang { color: var(--muted); font-size: .8rem; text-transform: uppercase; letter-spacing: .08em; }

p, li { margin: .6rem 0; }

ul { padding-left: 1.3rem; }

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

code {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: .1em .35em;
  font-size: .9em;
}

.table-wrap { overflow-x: auto; margin: 1rem 0; }

table { border-collapse: collapse; width: 100%; min-width: 24rem; font-size: .95rem; }

th, td { text-align: left; padding: .55rem .75rem; border-bottom: 1px solid var(--line); vertical-align: top; }

th { font-weight: 600; background: var(--card); }

nav { margin-bottom: 2.5rem; font-size: .95rem; }

nav a, nav strong { margin-right: 1.25rem; }

footer {
  margin-top: 4rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: .9rem;
}

.todo {
  background: #fff4d6;
  border: 1px solid #e0c168;
  color: #5a4300;
  border-radius: 6px;
  padding: .9rem 1.1rem;
  margin: 1.5rem 0;
  font-size: .93rem;
}

@media (prefers-color-scheme: dark) {
  .todo { background: #3a3116; border-color: #6d5b22; color: #f0dfae; }
}