:root {
  --bg: #faf7f2;
  --bg-alt: #f2ede4;
  --surface: #ffffff;
  --ink: #1f2421;
  --ink-soft: #545b56;
  --line: #e3ddd2;
  --accent: #2f6b4f;
  --accent-soft: #e3efe7;
  --warm: #c9774a;
  --radius: 18px;
  --max: 1120px;
  --font: "Noto Sans TC", "PingFang TC", "Microsoft JhengHei", system-ui, sans-serif;
  --serif: "Noto Serif TC", "Songti TC", Georgia, serif;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #141715;
    --bg-alt: #1b1f1c;
    --surface: #202522;
    --ink: #ecebe6;
    --ink-soft: #a9aea9;
    --line: #2f3531;
    --accent: #7cc09a;
    --accent-soft: #1f3328;
    --warm: #e39a6f;
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font);
  font-size: 17px;
  line-height: 1.75;
  letter-spacing: 0.01em;
}
a { color: var(--accent); text-underline-offset: 3px; }
a:hover { text-decoration-thickness: 2px; }
img, svg { max-width: 100%; }
:focus-visible { outline: 3px solid var(--warm); outline-offset: 3px; border-radius: 6px; }

/* ---------- i18n ---------- */
html[data-lang="zh"] [data-l="en"],
html[data-lang="en"] [data-l="zh"] { display: none !important; }

/* ---------- layout ---------- */
.wrap { width: 100%; max-width: var(--max); margin: 0 auto; padding: 0 24px; }
@media (max-width: 600px) { .wrap { padding: 0 16px; } body { font-size: 16px; } }

/* ---------- header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 20;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.site-header .wrap { display: flex; align-items: center; gap: 24px; height: 68px; }
.brand { display: flex; align-items: center; gap: 10px; color: var(--ink); text-decoration: none; font-weight: 700; }
.brand svg { width: 34px; height: 34px; flex: none; }
.brand small { display: block; font-weight: 500; font-size: 12px; color: var(--ink-soft); letter-spacing: 0.06em; line-height: 1.2; }
.brand span { line-height: 1.2; }
.nav { display: flex; gap: 22px; margin-left: auto; align-items: center; }
.nav a { color: var(--ink-soft); text-decoration: none; font-size: 15px; }
.nav a:hover { color: var(--ink); }
.lang-btn {
  border: 1px solid var(--line); background: var(--surface); color: var(--ink);
  border-radius: 999px; padding: 6px 14px; font: inherit; font-size: 14px; cursor: pointer;
}
.lang-btn:hover { border-color: var(--accent); }
@media (max-width: 760px) {
  .nav a { display: none; }
  .nav { gap: 0; }
}

/* ---------- hero ---------- */
.hero { padding: 96px 0 80px; position: relative; overflow: hidden; }
.hero::before {
  content: ""; position: absolute; right: -160px; top: -120px; width: 520px; height: 520px;
  border-radius: 50%;
  background: radial-gradient(circle, var(--accent-soft) 0%, transparent 70%);
  z-index: -1;
}
.eyebrow { display: inline-block; font-size: 14px; letter-spacing: 0.12em; color: var(--accent); font-weight: 600; margin-bottom: 18px; }
.hero h1 {
  font-family: var(--serif); font-weight: 700;
  font-size: clamp(36px, 6vw, 64px); line-height: 1.25; margin: 0 0 24px; letter-spacing: 0.02em;
}
.hero h1 em { font-style: normal; color: var(--accent); }
.hero p.lead { font-size: clamp(17px, 2vw, 20px); color: var(--ink-soft); max-width: 640px; margin: 0 0 36px; }
.btns { display: flex; gap: 12px; flex-wrap: wrap; }
.btn {
  display: inline-flex; align-items: center; gap: 8px; padding: 12px 24px; border-radius: 999px;
  text-decoration: none; font-weight: 600; font-size: 16px; border: 1px solid transparent;
}
.btn-primary { background: var(--accent); color: var(--bg); }
.btn-primary:hover { filter: brightness(1.08); }
.btn-ghost { border-color: var(--line); color: var(--ink); background: var(--surface); }
.btn-ghost:hover { border-color: var(--accent); }

/* ---------- sections ---------- */
section { padding: 88px 0; }
section.alt { background: var(--bg-alt); }
.sec-head { max-width: 680px; margin-bottom: 48px; }
.sec-head h2 { font-family: var(--serif); font-size: clamp(28px, 4vw, 40px); line-height: 1.35; margin: 0 0 14px; }
.sec-head p { color: var(--ink-soft); margin: 0; }

.grid { display: grid; gap: 20px; grid-template-columns: repeat(3, 1fr); }
@media (max-width: 900px) { .grid { grid-template-columns: 1fr; } }
.card {
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 32px 28px; display: flex; flex-direction: column;
}
.card .icon {
  width: 48px; height: 48px; border-radius: 14px; background: var(--accent-soft); color: var(--accent);
  display: grid; place-items: center; margin-bottom: 20px;
}
.card .icon svg { width: 26px; height: 26px; }
.card h3 { margin: 0 0 10px; font-size: 21px; line-height: 1.45; }
.card p { color: var(--ink-soft); margin: 0 0 16px; }
.card ul { margin: auto 0 0; padding: 16px 0 0; list-style: none; border-top: 1px dashed var(--line); }
.card li { position: relative; padding-left: 18px; font-size: 15px; color: var(--ink-soft); margin: 4px 0; }
.card li::before { content: ""; position: absolute; left: 0; top: 0.75em; width: 7px; height: 7px; border-radius: 50%; background: var(--warm); }

/* about */
.about { display: grid; grid-template-columns: 1.1fr 1fr; gap: 56px; align-items: start; }
@media (max-width: 900px) { .about { grid-template-columns: 1fr; gap: 32px; } }
.about p { color: var(--ink-soft); margin: 0 0 16px; }
.values { display: grid; gap: 16px; }
.value { border-left: 3px solid var(--accent); padding: 6px 0 6px 20px; }
.value h4 { margin: 0 0 4px; font-family: var(--serif); font-size: 20px; }
.value p { margin: 0; font-size: 15px; }

/* lab */
.lab {
  background: var(--surface); border: 1px solid var(--line); border-radius: 24px; padding: 48px;
  display: grid; grid-template-columns: 1fr 1fr; gap: 40px; align-items: center;
}
@media (max-width: 900px) { .lab { grid-template-columns: 1fr; padding: 32px 24px; } }
.lab h2 { font-family: var(--serif); font-size: clamp(26px, 3.5vw, 36px); margin: 0 0 14px; line-height: 1.35; }
.lab p { color: var(--ink-soft); margin: 0 0 12px; }
.chips { display: flex; flex-wrap: wrap; gap: 10px; }
.chip { padding: 8px 16px; border-radius: 999px; background: var(--accent-soft); color: var(--accent); font-weight: 600; font-size: 15px; }

/* contact */
.contact { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }
@media (max-width: 760px) { .contact { grid-template-columns: 1fr; } }
.contact .item { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 24px 26px; }
.contact .label { font-size: 13px; letter-spacing: 0.1em; color: var(--ink-soft); text-transform: uppercase; margin-bottom: 6px; }
.contact .val { font-size: 18px; font-weight: 600; word-break: break-word; }
.contact .val a { color: var(--ink); text-decoration: none; }
.contact .val a:hover { color: var(--accent); }

/* ---------- footer ---------- */
.site-footer { border-top: 1px solid var(--line); padding: 40px 0 48px; font-size: 14px; color: var(--ink-soft); }
.site-footer .wrap { display: flex; flex-wrap: wrap; gap: 16px 32px; justify-content: space-between; }
.site-footer nav { display: flex; gap: 20px; flex-wrap: wrap; }
.site-footer a { color: var(--ink-soft); text-decoration: none; }
.site-footer a:hover { color: var(--ink); }

/* ---------- legal pages ---------- */
.legal { padding: 64px 0 96px; }
.legal .doc { max-width: 780px; margin: 0 auto; }
.legal h1 { font-family: var(--serif); font-size: clamp(30px, 5vw, 44px); margin: 0 0 8px; line-height: 1.3; }
.legal .meta { color: var(--ink-soft); font-size: 15px; margin: 0 0 40px; padding-bottom: 24px; border-bottom: 1px solid var(--line); }
.legal h2 { font-size: 21px; margin: 44px 0 12px; line-height: 1.5; }
.legal h3 { font-size: 17px; margin: 24px 0 8px; }
.legal p, .legal li { color: var(--ink); }
.legal ul, .legal ol { padding-left: 1.4em; }
.legal li { margin: 6px 0; }
.legal table { width: 100%; border-collapse: collapse; margin: 12px 0 20px; font-size: 15px; }
.legal th, .legal td { border: 1px solid var(--line); padding: 10px 12px; text-align: left; vertical-align: top; }
.legal th { background: var(--bg-alt); width: 30%; font-weight: 600; }
.legal .toc { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 20px 24px; margin-bottom: 8px; }
.legal .toc ol { margin: 8px 0 0; columns: 2; column-gap: 32px; font-size: 15px; }
@media (max-width: 600px) { .legal .toc ol { columns: 1; } }
.legal .toc a { color: var(--ink-soft); text-decoration: none; }
.legal .toc a:hover { color: var(--accent); }
.legal .note { background: var(--accent-soft); border-radius: 12px; padding: 14px 18px; font-size: 15px; }