:root {
  color-scheme: light;
  --bg: #f4f7f5;
  --surface: #ffffff;
  --surface-soft: #edf6f2;
  --text: #16211d;
  --muted: #596761;
  --line: #d7e2dc;
  --accent: #0d6b5d;
  --accent-dark: #09493f;
  --accent-soft: #dff3ec;
  --warning: #fff6e8;
  --shadow: 0 24px 60px rgba(22, 33, 29, 0.08);
}

* {
  box-sizing: border-box;
}

html {
  background: var(--bg);
}

body {
  margin: 0;
  background:
    linear-gradient(180deg, rgba(223, 243, 236, 0.72), rgba(244, 247, 245, 0) 360px),
    var(--bg);
  color: var(--text);
  font-family: "Segoe UI", "Microsoft YaHei", "PingFang SC", "Helvetica Neue", Arial, sans-serif;
  line-height: 1.72;
}

a {
  color: var(--accent);
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

.site-header {
  align-items: center;
  display: grid;
  gap: 16px;
  grid-template-columns: minmax(190px, 1fr) auto auto;
  margin: 0 auto;
  max-width: 1100px;
  padding: 22px 20px 0;
}

.brand {
  align-items: center;
  color: var(--text);
  display: inline-flex;
  gap: 12px;
  text-decoration: none;
}

.brand-mark {
  align-items: center;
  background: var(--accent-dark);
  border-radius: 8px;
  color: white;
  display: inline-flex;
  font-size: 21px;
  font-weight: 800;
  height: 42px;
  justify-content: center;
  width: 42px;
}

.brand strong,
.brand small {
  display: block;
}

.brand strong {
  font-size: 17px;
  line-height: 1.15;
}

.brand small {
  color: var(--muted);
  font-size: 12px;
  margin-top: 2px;
}

.top-nav {
  align-items: center;
  display: flex;
  gap: 6px;
}

.top-nav a {
  border-radius: 8px;
  color: var(--muted);
  font-size: 14px;
  padding: 8px 10px;
  text-decoration: none;
}

.top-nav a:hover,
.top-nav a[aria-current="page"] {
  background: var(--accent-soft);
  color: var(--accent-dark);
}

.language-toggle {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 10px;
  display: inline-flex;
  padding: 3px;
}

.language-toggle button {
  background: transparent;
  border: 0;
  border-radius: 7px;
  color: var(--muted);
  cursor: pointer;
  font: inherit;
  font-size: 14px;
  line-height: 1;
  min-height: 34px;
  padding: 8px 12px;
}

.language-toggle button[aria-pressed="true"] {
  background: var(--accent);
  color: white;
}

.shell {
  margin: 0 auto;
  max-width: 1100px;
  padding: 42px 20px 72px;
}

.home-shell {
  display: grid;
  gap: 22px;
}

.hero,
.document,
.notice-block {
  background: rgba(255, 255, 255, 0.92);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.hero {
  display: grid;
  gap: 28px;
  grid-template-columns: minmax(0, 1.35fr) minmax(280px, 0.65fr);
  padding: 42px;
}

.eyebrow {
  color: var(--accent);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0;
  margin: 0 0 12px;
  text-transform: uppercase;
}

h1,
h2 {
  line-height: 1.24;
}

h1 {
  font-size: clamp(30px, 4vw, 52px);
  margin: 0;
}

h2 {
  font-size: 24px;
  margin: 36px 0 10px;
}

p {
  color: var(--muted);
  margin: 10px 0;
}

.lede {
  font-size: 18px;
  max-width: 720px;
}

.facts {
  background: var(--surface-soft);
  border: 1px solid #c9ded4;
  border-radius: 8px;
  display: grid;
  gap: 0;
  margin: 0;
  overflow: hidden;
}

.facts div {
  border-bottom: 1px solid #c9ded4;
  padding: 14px 16px;
}

.facts div:last-child {
  border-bottom: 0;
}

.facts dt {
  color: var(--accent-dark);
  font-size: 12px;
  font-weight: 700;
  margin-bottom: 4px;
  text-transform: uppercase;
}

.facts dd {
  color: var(--text);
  margin: 0;
  overflow-wrap: anywhere;
}

.facts.compact {
  margin: 22px 0 26px;
}

.doc-grid {
  display: grid;
  gap: 16px;
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.doc-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 8px;
  color: var(--text);
  display: grid;
  gap: 10px;
  min-height: 178px;
  padding: 24px;
  text-decoration: none;
  transition: border-color 160ms ease, transform 160ms ease, box-shadow 160ms ease;
}

.doc-card:hover {
  border-color: var(--accent);
  box-shadow: 0 18px 36px rgba(13, 107, 93, 0.12);
  transform: translateY(-2px);
}

.doc-card strong {
  color: var(--accent-dark);
  font-size: 24px;
}

.doc-card span:last-child {
  color: var(--muted);
}

.doc-index {
  color: var(--accent);
  font-size: 13px;
  font-weight: 800;
}

.notice-block {
  background: var(--warning);
  box-shadow: none;
  padding: 24px;
}

.notice-block h2 {
  color: #7a3d00;
  font-size: 20px;
  margin: 0 0 8px;
}

.notice-block p {
  color: #6d4b1f;
}

.document-shell {
  max-width: 980px;
}

.document {
  padding: 42px;
}

.document h1 {
  font-size: clamp(30px, 3.2vw, 44px);
}

.document section {
  border-top: 1px solid var(--line);
  margin-top: 30px;
  padding-top: 4px;
}

.document section:first-of-type {
  border-top: 0;
  margin-top: 0;
}

.in-document {
  margin-top: 26px;
}

ul {
  color: var(--muted);
  margin: 10px 0 0 1.2em;
  padding: 0;
}

li {
  margin: 7px 0;
}

.table-wrap {
  border: 1px solid var(--line);
  border-radius: 8px;
  margin-top: 14px;
  overflow-x: auto;
}

table {
  border-collapse: collapse;
  min-width: 760px;
  width: 100%;
}

th,
td {
  border-bottom: 1px solid var(--line);
  border-right: 1px solid var(--line);
  padding: 13px;
  text-align: left;
  vertical-align: top;
}

th:last-child,
td:last-child {
  border-right: 0;
}

tr:last-child td {
  border-bottom: 0;
}

th {
  background: var(--accent-soft);
  color: var(--accent-dark);
  font-size: 14px;
}

td {
  color: var(--muted);
  font-size: 14px;
}

.lang-en {
  display: none;
}

html[data-lang="en"] .lang-zh {
  display: none;
}

html[data-lang="en"] .lang-en {
  display: inline;
}

html[data-lang="en"] p.lang-en,
html[data-lang="en"] section.lang-en {
  display: block;
}

html[data-lang="zh"] .lang-zh {
  display: inline;
}

html[data-lang="zh"] p.lang-zh,
html[data-lang="zh"] section.lang-zh {
  display: block;
}

@media (max-width: 780px) {
  .site-header {
    align-items: stretch;
    grid-template-columns: 1fr;
  }

  .top-nav {
    flex-wrap: wrap;
  }

  .language-toggle {
    justify-self: start;
  }

  .shell {
    padding: 28px 14px 52px;
  }

  .hero {
    grid-template-columns: 1fr;
    padding: 28px;
  }

  .doc-grid {
    grid-template-columns: 1fr;
  }

  .document {
    padding: 28px;
  }
}

@media (max-width: 460px) {
  .site-header {
    padding-left: 14px;
    padding-right: 14px;
  }

  .top-nav a,
  .language-toggle button {
    font-size: 13px;
  }

  .hero,
  .document,
  .notice-block,
  .doc-card {
    padding: 22px;
  }

  .brand-mark {
    height: 38px;
    width: 38px;
  }
}