:root {
    color-scheme: light dark;
    --bg: #ffffff;
    --fg: #1b1f24;
    --muted: #5b6470;
    --border: #e2e5e9;
    --code-bg: #f4f6f8;
    --accent: #3b6df0;
    --table-head: #f0f2f5;
  }
  @media (prefers-color-scheme: dark) {
    :root {
      --bg: #14171c;
      --fg: #e7eaee;
      --muted: #9aa4b2;
      --border: #2a2f37;
      --code-bg: #1c2027;
      --accent: #6f9bff;
      --table-head: #1c2027;
    }
  }
  * { box-sizing: border-box; }
  body {
    margin: 0;
    background: var(--bg);
    color: var(--fg);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang TC", "Noto Sans TC", sans-serif;
    line-height: 1.65;
  }
  .wrap {
    max-width: 860px;
    margin: 0 auto;
    padding: 2.5rem 1.25rem 5rem;
  }
  header.hero {
    padding: 3rem 0 2rem;
    border-bottom: 1px solid var(--border);
    margin-bottom: 2.5rem;
  }
  header.hero h1 {
    font-size: 2rem;
    margin: 0 0 0.5rem;
  }
  header.hero p {
    color: var(--muted);
    margin: 0;
    font-size: 1.05rem;
  }
  nav.toc {
    display: flex;
    gap: 1.25rem;
    flex-wrap: wrap;
    margin-top: 1.25rem;
    font-size: 0.92rem;
  }
  nav.toc a {
    color: var(--accent);
    text-decoration: none;
  }
  nav.toc a:hover { text-decoration: underline; }
  section { margin-bottom: 3rem; }
  h2 {
    font-size: 1.4rem;
    border-bottom: 1px solid var(--border);
    padding-bottom: 0.5rem;
    margin-top: 2.5rem;
  }
  h3 { font-size: 1.1rem; margin-top: 1.75rem; }
  p { margin: 0.85rem 0; }
  code {
    background: var(--code-bg);
    padding: 0.15em 0.4em;
    border-radius: 4px;
    font-size: 0.88em;
    font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
  }
  pre {
    background: var(--code-bg);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 1rem;
    overflow-x: auto;
    font-size: 0.85rem;
  }
  pre code {
    background: none;
    padding: 0;
    font-size: inherit;
  }
  table {
    width: 100%;
    border-collapse: collapse;
    margin: 1.25rem 0;
    font-size: 0.92rem;
    display: block;
    overflow-x: auto;
  }
  th, td {
    border: 1px solid var(--border);
    padding: 0.5rem 0.7rem;
    text-align: left;
    vertical-align: top;
  }
  th { background: var(--table-head); }
  ul, ol { padding-left: 1.4rem; }
  li { margin: 0.35rem 0; }
  blockquote {
    margin: 1rem 0;
    padding: 0.6rem 1rem;
    border-left: 3px solid var(--accent);
    background: var(--code-bg);
    color: var(--muted);
  }
  blockquote p { margin: 0.3rem 0; }
  footer {
    color: var(--muted);
    font-size: 0.85rem;
    border-top: 1px solid var(--border);
    padding-top: 1.5rem;
    margin-top: 3rem;
  }
  a { color: var(--accent); }
.product-card {
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.25rem 1.4rem;
  max-width: 560px;
}
.product-card h3 { margin: 0 0 0.35rem; }
.product-card p { color: var(--muted); }
.product-link { text-decoration: none; }
.product-link:hover { text-decoration: underline; }