:root {
  --bg: #ffffff; --bg2: #f5f7f9; --fg: #1b1f24; --muted: #5a6270;
  --link: #0a5bb0; --line: #e2e6ea; --accent: #0a7d55; --warn: #a15c00;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #101317; --bg2: #171b21; --fg: #e5e8eb; --muted: #98a0aa;
    --link: #6fb2ff; --line: #2a3038; --accent: #4cc99a; --warn: #f0b35a;
  }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--bg); color: var(--fg);
       font: 16px/1.65 system-ui, -apple-system, "Segoe UI", Roboto, "Noto Sans",
             "PingFang TC", "Microsoft JhengHei", "PingFang SC", "Microsoft YaHei", sans-serif; }
a { color: var(--link); }
code { font: 0.92em ui-monospace, SFMono-Regular, Consolas, monospace; }
pre { background: var(--bg2); border: 1px solid var(--line); border-radius: 6px;
      padding: 12px 14px; overflow-x: auto; }
pre code { font-size: 0.88em; }

header { border-bottom: 1px solid var(--line); background: var(--bg); }
.bar { max-width: 1040px; margin: 0 auto; padding: 10px 16px;
       display: flex; flex-wrap: wrap; align-items: center; gap: 6px 18px; }
.brand { font-weight: 700; font-size: 1.15rem; color: var(--fg); text-decoration: none; margin-right: auto; }
nav { display: flex; flex-wrap: wrap; gap: 4px 14px; font-size: 0.95rem; }
nav a { color: var(--muted); text-decoration: none; }
nav a:hover, nav a.on { color: var(--fg); }
nav a.on { font-weight: 600; }
.langs { position: relative; font-size: 0.85rem; }
.langs summary { cursor: pointer; list-style: none; padding: 4px 10px; border: 1px solid var(--line);
  border-radius: 6px; color: var(--fg); white-space: nowrap; user-select: none; }
.langs summary::-webkit-details-marker { display: none; }
.langs summary::before { content: "🌐 "; }
.langs summary::after { content: " ▾"; color: var(--muted); }
.langs .menu { position: absolute; right: 0; top: calc(100% + 4px); z-index: 10; min-width: 120px;
  background: var(--bg); border: 1px solid var(--line); border-radius: 6px; padding: 4px 0;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15); }
.langs .menu a { display: block; padding: 6px 12px; color: var(--fg); text-decoration: none; white-space: nowrap; }
.langs .menu a:hover { background: var(--bg2); }
.langs .menu a.on { font-weight: 600; color: var(--accent); }

main { max-width: 1040px; margin: 0 auto; padding: 28px 16px 48px; }
h1 { font-size: 2rem; line-height: 1.25; margin: 8px 0 12px; }
h2 { font-size: 1.35rem; margin: 40px 0 10px; }
h3 { font-size: 1.05rem; margin: 22px 0 6px; }
.lead { font-size: 1.15rem; color: var(--muted); max-width: 760px; }
.prose { max-width: 760px; }

.hero { padding: 24px 0 8px; }
.stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 12px; margin: 22px 0; }
.stat { background: var(--bg2); border: 1px solid var(--line); border-radius: 8px; padding: 14px 16px; }
.stat b { display: block; font-size: 1.9rem; color: var(--accent); line-height: 1.2; }
.stat span { color: var(--muted); font-size: 0.92rem; }
.btns { display: flex; flex-wrap: wrap; gap: 10px; margin: 18px 0; }
.btn { display: inline-block; padding: 9px 16px; border-radius: 6px; text-decoration: none;
       border: 1px solid var(--line); color: var(--fg); background: var(--bg2); }
.btn.primary { background: var(--accent); border-color: var(--accent); color: #fff; }

.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 12px; margin: 14px 0; }
.card { display: block; border: 1px solid var(--line); border-radius: 8px; padding: 14px 16px;
        color: var(--fg); text-decoration: none; background: var(--bg); }
.card:hover { border-color: var(--link); }
.card b { display: block; margin-bottom: 4px; }
.card span { color: var(--muted); font-size: 0.93rem; }

.tw { overflow-x: auto; }
table { border-collapse: collapse; width: 100%; margin: 10px 0; font-size: 0.95rem; }
th, td { text-align: left; padding: 7px 10px; border-bottom: 1px solid var(--line); vertical-align: top; }
th { color: var(--muted); font-weight: 600; }
td.n, th.n { text-align: right; white-space: nowrap; font-variant-numeric: tabular-nums; }
.good { color: var(--accent); font-weight: 600; }
.cost { color: var(--warn); font-weight: 600; }
.note { color: var(--muted); font-size: 0.9rem; }
ul.list { padding-left: 1.2em; }
ul.list li { margin: 4px 0; }

footer { border-top: 1px solid var(--line); background: var(--bg2); }
.foot { max-width: 1040px; margin: 0 auto; padding: 18px 16px 28px; color: var(--muted); font-size: 0.85rem; }
.foot p { margin: 6px 0; }