:root {
  --ink: #0c2a32;
  --ink-2: #134048;
  --gold: #eab308;
  --gold-2: #f5d56a;
  --teal: #0d9488;
  --blue: #0369a1;
  --paper: #eef6f5;
  --cream: #f8fafc;
  --white: #ffffff;
  --text: #14323a;
  --muted: #5a6d73;
  --line: #d5e4e2;
  --wood: #0d9488;
  --water: #0369a1;
  --earth: #8b7355;
  --fire: #b45309;
  --max: 1140px;
  --radius: 14px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
:focus-visible {
  outline: 2px solid var(--teal);
  outline-offset: 3px;
}
.skip {
  position: absolute;
  left: -999px;
  top: 8px;
  z-index: 80;
  background: var(--gold);
  color: #14323a;
  padding: 8px 14px;
  border-radius: 8px;
  font-weight: 700;
}
.skip:focus {
  left: 12px;
}
body {
  margin: 0;
  font-family: "Be Vietnam Pro", "Segoe UI", Tahoma, sans-serif;
  color: var(--text);
  background: var(--cream);
  line-height: 1.7;
}
a { color: #0a7a70; text-decoration: none; }
a:hover { color: var(--ink); text-decoration: underline; }
img { max-width: 100%; height: auto; }

.wrap { max-width: var(--max); margin: 0 auto; padding: 0 22px; }

.gold-line {
  height: 3px;
  background: linear-gradient(90deg, transparent, var(--gold), var(--gold-2), var(--gold), transparent);
}

.topbar {
  background: var(--ink);
  color: #c9d3d8;
  font-size: 13px;
  padding: 8px 0;
}
.topbar .wrap { display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap; }
.topbar a { color: var(--gold); }
.langs { display: flex; gap: 8px; align-items: center; }
.langs a {
  color: #c9d3d8;
  font-weight: 700;
  font-size: 12px;
  letter-spacing: 0.06em;
  padding: 2px 8px;
  border: 1px solid #3d5c62;
  border-radius: 999px;
  text-decoration: none;
}
.langs a:hover, .langs a.on { color: #0a2428; background: var(--gold); border-color: var(--gold); text-decoration: none; }
html[lang="zh-CN"] body { font-family: "Noto Sans SC", "Be Vietnam Pro", sans-serif; }

header.site {
  background: rgba(255, 252, 247, 0.96);
  border-bottom: 1px solid var(--line);
  position: sticky;
  top: 0;
  z-index: 30;
  backdrop-filter: blur(8px);
}
header.site .wrap { position: relative; }
header.site .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  min-height: 78px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--ink);
  text-decoration: none;
  flex-shrink: 0;
}
.brand:hover { text-decoration: none; }
.brand img {
  width: 52px;
  height: 52px;
  display: block;
  flex-shrink: 0;
}
.brand strong {
  display: block;
  font-family: Montserrat, "Be Vietnam Pro", sans-serif;
  font-size: 20px;
  letter-spacing: 0.04em;
  line-height: 1.1;
  color: var(--teal);
}
.brand em {
  display: block;
  font-style: normal;
  font-size: 11px;
  color: var(--muted);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-top: 4px;
}

.nav-toggle { display: none; }
.nav-btn {
  display: none;
  border: 1px solid var(--line);
  background: #fff;
  padding: 8px 12px;
  font-weight: 600;
  cursor: pointer;
  border-radius: 8px;
}

nav.menu { display: flex; align-items: center; flex-wrap: wrap; gap: 4px 6px; }
nav.menu a, nav.menu .drop > span, nav.menu .drop > a {
  color: var(--ink);
  font-size: 14px;
  font-weight: 600;
  text-decoration: none;
  padding: 8px 10px;
  border-radius: 8px;
  display: inline-block;
}
nav.menu a:hover, nav.menu .drop:hover > span, nav.menu .drop:hover > a {
  color: var(--teal);
  background: #e6f4f2;
  text-decoration: none;
}
nav.menu a.on, nav.menu .drop > span.on, nav.menu .drop > a.on { color: var(--teal); background: #e6f4f2; }
.drop { position: relative; }
.drop > span { cursor: default; }
.drop > span::after, .drop > a::after { content: " ▾"; font-size: 10px; color: var(--gold); }
.drop-list {
  display: none;
  position: absolute;
  top: 100%;
  left: 0;
  min-width: 248px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 8px;
  box-shadow: 0 12px 32px rgba(15, 28, 36, 0.1);
}
.drop:hover .drop-list, .drop:focus-within .drop-list { display: block; }
.drop-list a { display: block; font-weight: 500; }
.nav-cta {
  margin-left: 6px;
  background: var(--teal) !important;
  color: #fff !important;
  border-radius: 999px !important;
  padding: 8px 16px !important;
}
.nav-cta:hover { background: #17303a !important; color: #fff !important; }

.hero {
  background:
    radial-gradient(circle at 12% 20%, rgba(13, 148, 136, 0.22), transparent 36%),
    radial-gradient(circle at 88% 80%, rgba(3, 105, 161, 0.28), transparent 40%),
    linear-gradient(160deg, #0a2428 0%, #0d3d42 55%, #0c2a32 100%);
  color: var(--paper);
  padding: 72px 0 64px;
  position: relative;
}
.hero::after {
  content: "";
  position: absolute;
  left: 10%;
  right: 10%;
  bottom: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--gold), transparent);
}
.hero p.kicker {
  color: var(--gold-2);
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  margin: 0 0 14px;
  font-weight: 600;
}
.hero h1 {
  margin: 0 0 18px;
  font-family: Montserrat, "Be Vietnam Pro", sans-serif;
  font-size: clamp(32px, 4.6vw, 48px);
  line-height: 1.22;
  color: #fff;
  font-weight: 600;
  max-width: 18em;
}
.hero .lead { max-width: 720px; color: #d5dde2; font-size: 18px; }
.actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 28px; }
.btn {
  display: inline-block;
  padding: 12px 20px;
  font-weight: 700;
  font-size: 14px;
  text-decoration: none;
  border: 1px solid transparent;
  border-radius: 999px;
}
.btn:hover { text-decoration: none; }
.btn-primary { background: var(--gold); color: #14323a; }
.btn-primary:hover { background: var(--gold-2); color: #14323a; }
.btn-ghost { border-color: #7d8b93; color: #fff; }
.btn-ghost:hover { border-color: var(--gold); color: var(--gold-2); }
.btn-on-light { background: var(--teal); color: #fff; }
.btn-on-light:hover { background: #17303a; color: #fff; text-decoration: none; }

section { padding: 56px 0; }
section.alt { background: var(--paper); }
section.ink {
  background: var(--ink-2);
  color: #d7dee3;
}
section.ink h2, section.ink h3 { color: #fff; }
section.ink p, section.ink li { color: #c9d3d8; }
h2 {
  font-family: Montserrat, "Be Vietnam Pro", sans-serif;
  font-size: 32px;
  margin: 0 0 18px;
  font-weight: 600;
  line-height: 1.25;
}
h3 { font-size: 18px; margin: 28px 0 8px; }
.subhead { color: var(--muted); margin: -8px 0 28px; max-width: 720px; line-height: 1.55; }
section.ink .subhead { color: #b7c2c8; }

.grid-5, .grid-4, .grid-3, .grid-2 {
  display: grid;
  gap: 18px;
}
.grid-5 { grid-template-columns: repeat(5, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-2 { grid-template-columns: 1fr 1fr; }
.prose .grid-2 { margin: 22px 0 28px; }

.card {
  background: #fff;
  border: 1px solid var(--line);
  padding: 22px 20px 20px;
  border-radius: var(--radius);
  text-decoration: none;
  color: inherit;
  display: block;
  height: 100%;
  box-shadow: 0 1px 0 rgba(196, 163, 90, 0.12);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}
a.card:hover {
  text-decoration: none;
  transform: translateY(-3px);
  box-shadow: 0 10px 24px rgba(15, 28, 36, 0.08);
}
.card h3 { margin: 8px 0 8px; color: var(--ink); }
.card p { color: var(--muted); margin: 0; }
.card .mark {
  display: inline-block;
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  font-weight: 700;
  margin-bottom: 4px;
}
.card.water { border-top: 3px solid var(--water); }
.card.water .mark { color: var(--water); }
.card.metal { border-top: 3px solid var(--gold); }
.card.metal .mark { color: #b8860b; }
.card.earth { border-top: 3px solid var(--earth); }
.card.earth .mark { color: var(--earth); }
.card.fire { border-top: 3px solid var(--fire); }
.card.fire .mark { color: var(--fire); }
.card.wood { border-top: 3px solid var(--wood); }
.card.wood .mark { color: var(--wood); }

.stat {
  text-align: center;
  padding: 8px;
}
.stat b {
  display: block;
  font-family: Montserrat, "Be Vietnam Pro", sans-serif;
  font-size: 28px;
  color: var(--gold);
  font-weight: 600;
}
.stat span { color: #b7c2c8; font-size: 13px; }

.prose { max-width: 780px; }
.prose.wide { max-width: 920px; }
.prose p, .prose li { color: #2a3340; }
.prose ul, .prose ol { padding-left: 22px; }
.prose li { margin: 6px 0; }
.note {
  border-left: 3px solid var(--gold);
  padding: 12px 16px;
  background: #fff8ea;
  font-size: 15px;
  border-radius: 0 10px 10px 0;
}
.toc-list { list-style: none; padding: 0; }
.toc-list li { margin: 0 0 10px; padding-bottom: 10px; border-bottom: 1px solid var(--line); }
.toc-list a { font-weight: 600; }

.steps {
  counter-reset: step;
  list-style: none;
  padding: 0;
  margin: 0;
}
.steps li {
  position: relative;
  padding: 0 0 22px 56px;
  border-left: 1px solid var(--line);
  margin-left: 16px;
}
.steps li:last-child { border-left-color: transparent; padding-bottom: 0; }
.steps li::before {
  counter-increment: step;
  content: counter(step);
  position: absolute;
  left: -16px;
  top: 0;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--ink);
  color: var(--gold-2);
  font-weight: 700;
  font-size: 13px;
  display: flex;
  align-items: center;
  justify-content: center;
}

footer.site {
  background: var(--ink);
  color: #c5cdd6;
  padding: 48px 0 22px;
  font-size: 14px;
}
footer.site a { color: var(--gold-2); }
footer.site h3 {
  color: #fff;
  margin: 0 0 12px;
  font-size: 15px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
footer.site .grid-3 { align-items: start; }
footer.site ul { list-style: none; padding: 0; margin: 0; }
footer.site li { margin: 6px 0; }
.legal {
  margin-top: 28px;
  padding-top: 16px;
  border-top: 1px solid #2a3d48;
  font-size: 12px;
  color: #8b95a3;
}

.crumbs {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 8px;
  align-items: center;
  padding-top: 18px;
  padding-bottom: 0;
  font-size: 13px;
  color: var(--muted);
}
.crumbs a { color: var(--muted); }
.crumbs .sep { color: #b7c4c8; }
.crumbs [aria-current="page"] { color: var(--ink); font-weight: 600; }

.faq details {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 0 18px;
  margin: 0 0 10px;
}
.faq summary {
  cursor: pointer;
  font-weight: 600;
  padding: 14px 0;
  list-style: none;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: "+";
  float: right;
  color: var(--teal);
  font-weight: 700;
}
.faq details[open] summary::after { content: "–"; }
.faq details p { margin: 0 0 16px; color: #2a3340; }

.brief {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px 20px;
}
.brief label {
  display: block;
  font-weight: 600;
  margin: 14px 0 6px;
  font-size: 14px;
}
.brief label:first-of-type { margin-top: 0; }
.brief input, .brief select, .brief textarea {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: 10px;
  font: inherit;
  background: #fff;
}
.brief textarea { min-height: 140px; resize: vertical; }
.brief .actions { margin-top: 18px; }
.brief button { cursor: pointer; border: 0; font: inherit; }

.related { margin-top: 36px; }
.related h2 { font-size: 24px; }

.dock { display: none; }

@media (max-width: 720px) {
  body { padding-bottom: 64px; }
  .dock {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 40;
    background: var(--ink);
    border-top: 2px solid var(--gold);
  }
  .dock a {
    color: #fff;
    text-align: center;
    padding: 14px 8px;
    font-weight: 700;
    font-size: 14px;
    text-decoration: none;
  }
  .dock a:hover { color: var(--gold-2); text-decoration: none; }
}

@media (max-width: 980px) {
  .grid-5, .grid-4 { grid-template-columns: 1fr 1fr; }
  .nav-btn { display: inline-block; }
  nav.menu {
    display: none;
    position: absolute;
    left: 0;
    right: 0;
    top: 100%;
    background: #fff;
    border-bottom: 1px solid var(--line);
    padding: 12px 22px 18px;
    flex-direction: column;
    align-items: stretch;
  }
  .nav-toggle:checked ~ nav.menu { display: flex; }
  .drop-list { position: static; box-shadow: none; border: 0; padding-left: 8px; }
  .drop:hover .drop-list, .drop .drop-list { display: block; }
  .nav-cta { margin-left: 0; text-align: center; }
}
@media (max-width: 720px) {
  .grid-5, .grid-4, .grid-3, .grid-2 { grid-template-columns: 1fr; }
  .hero { padding: 48px 0 42px; }
}