:root {
  --bg: #f7f7f5;
  --card: #ffffff;
  --text: #1f2328;
  --muted: #59636e;
  --border: #e3e3e0;
  --link: #0b63c4;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #15171a;
    --card: #1e2125;
    --text: #e6e6e3;
    --muted: #9aa3ad;
    --border: #30343a;
    --link: #6cb2ff;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: system-ui, -apple-system, "Segoe UI", "Noto Sans TC", "PingFang TC", "Microsoft JhengHei", sans-serif;
  line-height: 1.7;
}
main {
  max-width: 720px;
  margin: 0 auto;
  padding: 48px 16px 64px;
}
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 28px 24px;
}
h1 { font-size: 1.6rem; margin: 0 0 8px; line-height: 1.3; }
h2 { font-size: 1.1rem; margin: 28px 0 6px; }
p, li { margin: 6px 0; }
ul { padding-left: 1.3em; }
.muted { color: var(--muted); font-size: 0.92rem; }
.en { color: var(--muted); font-size: 0.92rem; }
a { color: var(--link); }
footer { margin-top: 24px; text-align: center; }