:root {
  color-scheme: light dark;
  --bg: #f7f7f4;
  --surface: rgba(255, 255, 255, 0.74);
  --surface-solid: #ffffff;
  --text: #151515;
  --muted: #6e6e69;
  --line: rgba(20, 20, 20, 0.11);
  --soft: rgba(20, 20, 20, 0.055);
  --green-1: #dce9d5;
  --green-2: #b8d2ad;
  --green-3: #86ad7c;
  --green-4: #4e7953;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0d0d0c;
    --surface: rgba(29, 29, 27, 0.76);
    --surface-solid: #191918;
    --text: #f5f5f1;
    --muted: #a6a6a0;
    --line: rgba(255, 255, 255, 0.13);
    --soft: rgba(255, 255, 255, 0.065);
  }
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  min-height: 100vh;
  background:
    radial-gradient(circle at 15% -10%, rgba(134, 173, 124, 0.13), transparent 34rem),
    var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Helvetica Neue", sans-serif;
  font-size: 17px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; }
.shell { width: min(1120px, calc(100% - 40px)); margin: 0 auto; }
.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  padding: 14px 0;
  background: color-mix(in srgb, var(--bg) 76%, transparent);
  border-bottom: 1px solid var(--line);
  -webkit-backdrop-filter: blur(22px) saturate(150%);
  backdrop-filter: blur(22px) saturate(150%);
}
.header-inner { display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.brand { display: inline-flex; align-items: center; gap: 12px; font-weight: 720; letter-spacing: -.025em; text-decoration: none; }
.mark { position: relative; width: 31px; height: 31px; transform: rotate(20deg); }
.mark i {
  position: absolute;
  inset: 5px;
  border-radius: 7px;
  border: 1px solid rgba(255,255,255,.36);
  transform: translate(calc(var(--n) * 2px), calc(var(--n) * -1px)) rotate(calc(var(--n) * 4deg));
  background: var(--c);
  box-shadow: 0 4px 10px rgba(40, 65, 42, .08);
}
.nav { display: flex; align-items: center; gap: 5px; }
.nav a, .language button {
  border: 0;
  border-radius: 999px;
  padding: 7px 11px;
  background: transparent;
  color: var(--muted);
  font: inherit;
  font-size: 13px;
  font-weight: 630;
  text-decoration: none;
  cursor: pointer;
}
.nav a:hover, .nav a[aria-current="page"], .language button.active { color: var(--text); background: var(--soft); }
.language { display: inline-flex; margin-left: 5px; padding-left: 8px; border-left: 1px solid var(--line); }
.hero { padding: clamp(80px, 12vw, 150px) 0 clamp(72px, 10vw, 120px); }
.eyebrow { color: var(--muted); font-size: 13px; font-weight: 720; letter-spacing: .1em; text-transform: uppercase; }
h1 { max-width: 930px; margin: 15px 0 23px; font-size: clamp(52px, 9vw, 105px); line-height: .98; letter-spacing: -.065em; }
.hero p { max-width: 720px; margin: 0; color: var(--muted); font-size: clamp(19px, 2.3vw, 25px); line-height: 1.5; letter-spacing: -.018em; }
.actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 34px; }
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0 19px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--surface-solid);
  font-size: 14px;
  font-weight: 680;
  text-decoration: none;
  box-shadow: 0 8px 28px rgba(0,0,0,.05);
}
.button.primary { background: var(--text); color: var(--bg); border-color: transparent; }
.grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; padding-bottom: 100px; }
.card {
  min-height: 270px;
  padding: 28px;
  border: 1px solid var(--line);
  border-radius: 28px;
  background: var(--surface);
  box-shadow: 0 18px 55px rgba(0,0,0,.045);
  -webkit-backdrop-filter: blur(18px);
  backdrop-filter: blur(18px);
}
.card-number { color: var(--muted); font-size: 12px; font-weight: 720; letter-spacing: .09em; }
.card h2 { margin: 74px 0 10px; font-size: 26px; line-height: 1.15; letter-spacing: -.035em; }
.card p { margin: 0; color: var(--muted); font-size: 15px; }
.promise { margin-bottom: 100px; padding: clamp(32px, 6vw, 68px); border-radius: 34px; background: var(--text); color: var(--bg); }
.promise h2 { max-width: 760px; margin: 0 0 17px; font-size: clamp(35px, 5vw, 59px); line-height: 1.05; letter-spacing: -.052em; }
.promise p { max-width: 620px; margin: 0; opacity: .72; font-size: 18px; }
.document-hero { padding: 75px 0 46px; border-bottom: 1px solid var(--line); }
.document-hero h1 { max-width: 850px; margin-bottom: 16px; font-size: clamp(47px, 7vw, 78px); }
.document-hero p { max-width: 720px; margin: 0; color: var(--muted); font-size: 19px; }
.document { display: grid; grid-template-columns: 230px minmax(0, 720px); gap: 62px; padding: 48px 0 100px; }
.toc { position: sticky; top: 91px; align-self: start; }
.toc strong { display: block; margin-bottom: 11px; font-size: 13px; }
.toc a { display: block; padding: 4px 0; color: var(--muted); font-size: 13px; text-decoration: none; }
.toc a:hover { color: var(--text); }
.content section { scroll-margin-top: 105px; padding: 0 0 35px; margin: 0 0 35px; border-bottom: 1px solid var(--line); }
.content section:last-child { border: 0; }
.content h2 { margin: 0 0 14px; font-size: 25px; line-height: 1.25; letter-spacing: -.03em; }
.content h3 { margin: 25px 0 8px; font-size: 17px; }
.content p { margin: 0 0 14px; }
.content ul { margin: 10px 0 16px; padding-left: 21px; }
.content li { margin: 7px 0; }
.callout { margin: 20px 0; padding: 18px 20px; border: 1px solid var(--line); border-radius: 18px; background: var(--surface); }
.callout strong { display: block; margin-bottom: 4px; }
.muted { color: var(--muted); }
.faq { padding: 50px 0 100px; }
.faq details { border-bottom: 1px solid var(--line); }
.faq summary { padding: 24px 0; cursor: pointer; font-size: 19px; font-weight: 670; list-style: none; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; float: right; color: var(--muted); font-weight: 400; }
.faq details[open] summary::after { content: "−"; }
.faq details p { max-width: 760px; margin: -5px 0 25px; color: var(--muted); }
.contact-panel { margin: 35px 0 100px; padding: 30px; border: 1px solid var(--line); border-radius: 25px; background: var(--surface); }
.contact-panel a { font-weight: 680; text-underline-offset: 4px; }
.site-footer { padding: 28px 0 45px; border-top: 1px solid var(--line); color: var(--muted); font-size: 13px; }
.footer-inner { display: flex; justify-content: space-between; gap: 20px; }
.footer-links { display: flex; flex-wrap: wrap; gap: 17px; }
.footer-links a { text-decoration: none; }
[data-lang] { display: none; }
html.lang-en [data-lang="en"], html.lang-zh [data-lang="zh"] { display: block; }

@media (max-width: 820px) {
  .nav > a { display: none; }
  .grid { grid-template-columns: 1fr; }
  .card { min-height: 220px; }
  .card h2 { margin-top: 45px; }
  .document { display: block; }
  .toc { position: static; margin-bottom: 45px; padding: 18px; border: 1px solid var(--line); border-radius: 18px; background: var(--surface); }
}
@media (max-width: 520px) {
  .shell { width: min(100% - 28px, 1120px); }
  .site-header { padding: 10px 0; }
  .brand { gap: 9px; }
  .mark { width: 28px; height: 28px; }
  .language { padding-left: 3px; margin-left: 0; }
  .language button { padding: 7px 8px; }
  .hero { padding-top: 68px; }
  h1 { font-size: 53px; }
  .card { border-radius: 23px; }
  .footer-inner { display: block; }
  .footer-links { margin-top: 12px; }
}