:root { --bg: #f9f8f5; --ink: #1f1c18; --mute: #6b665e; --rule: #e4e0d8; }
@media (prefers-color-scheme: dark) {
  :root { --bg: #1c1b19; --ink: #f2efe9; --mute: #a39e94; --rule: #35332f; }
}
* { box-sizing: border-box; }
body {
  margin: 0; background: var(--bg); color: var(--ink);
  font: 17px/1.65 -apple-system, "Helvetica Neue", "PingFang TC", "Noto Sans TC", sans-serif;
}
main { max-width: 640px; margin: 0 auto; padding: 56px 20px 80px; }
h1 { font-size: 2rem; line-height: 1.2; margin: 0 0 8px; }
h2 { font-size: 1.15rem; margin: 40px 0 8px; }
p, li { margin: 0 0 12px; }
ul { padding-left: 1.2em; }
a { color: inherit; text-underline-offset: 3px; }
.sub { color: var(--mute); margin-bottom: 32px; }
nav { margin-top: 48px; padding-top: 20px; border-top: 1px solid var(--rule); color: var(--mute); font-size: .95rem; }
nav a { margin-right: 18px; }
.zh { margin-top: 40px; padding-top: 24px; border-top: 1px solid var(--rule); }