:root {
  color-scheme: light dark;
  --bg: #f5f7f6;
  --surface: #ffffff;
  --text: #15211f;
  --muted: #5d6966;
  --line: #dce4e1;
  --accent: #177777;
  --accent-strong: #0e5f5f;
  --accent-soft: #e7f4f2;
  --notice: #f3f8f7;
  --shadow: 0 18px 50px rgba(14, 57, 52, 0.08);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: auto;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans SC",
    "PingFang SC", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.72;
  text-rendering: optimizeLegibility;
}

a {
  color: var(--accent-strong);
  text-underline-offset: 0.18em;
}

a:hover {
  text-decoration-thickness: 2px;
}

a:focus-visible,
button:focus-visible {
  outline: 3px solid color-mix(in srgb, var(--accent) 60%, transparent);
  outline-offset: 3px;
}

.skip-link {
  position: fixed;
  z-index: 20;
  top: 12px;
  left: 12px;
  padding: 10px 14px;
  border-radius: 8px;
  background: var(--text);
  color: var(--surface);
  transform: translateY(-160%);
}

.skip-link:focus {
  transform: translateY(0);
}

.site-header {
  border-bottom: 1px solid var(--line);
  background: color-mix(in srgb, var(--surface) 92%, transparent);
}

.header-inner,
.page-shell,
.site-footer {
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto;
}

.header-inner {
  display: flex;
  min-height: 76px;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.header-navs {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 18px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--text);
  font-weight: 720;
  letter-spacing: -0.01em;
  text-decoration: none;
}

.brand img {
  display: block;
  width: 56px;
  height: 32px;
}

.site-nav,
.language-nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 6px;
  font-size: 14px;
}

.site-nav a,
.language-nav a {
  padding: 7px 10px;
  border-radius: 999px;
  color: var(--muted);
  text-decoration: none;
}

.site-nav a[aria-current="page"],
.language-nav a[aria-current="page"] {
  background: var(--accent-soft);
  color: var(--accent-strong);
  font-weight: 700;
}

.site-nav a:hover,
.language-nav a:hover {
  color: var(--accent-strong);
}

.page-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 280px;
  gap: 32px;
  padding: 48px 0 72px;
  align-items: start;
}

.document {
  grid-column: 1;
  grid-row: 1;
  min-width: 0;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 20px;
  background: var(--surface);
  box-shadow: var(--shadow);
}

.document-hero {
  padding: 48px 52px 34px;
  border-bottom: 1px solid var(--line);
  background:
    radial-gradient(circle at 100% 0%, rgba(23, 119, 119, 0.16), transparent 36%),
    var(--surface);
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--accent-strong);
  font-size: 13px;
  font-weight: 750;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

h1,
h2,
h3 {
  line-height: 1.28;
  letter-spacing: -0.025em;
}

h1 {
  margin: 0;
  font-size: clamp(34px, 5vw, 52px);
}

.lede {
  max-width: 700px;
  margin: 20px 0 0;
  color: var(--muted);
  font-size: 18px;
}

.effective-date {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
  margin: 24px 0 0;
  color: var(--muted);
  font-size: 14px;
}

.document-body {
  padding: 12px 52px 52px;
  overflow-wrap: anywhere;
}

.summary-box,
.callout {
  margin: 28px 0;
  padding: 20px 22px;
  border: 1px solid color-mix(in srgb, var(--accent) 28%, var(--line));
  border-radius: 14px;
  background: var(--notice);
}

.summary-box strong,
.callout strong {
  display: block;
  margin-bottom: 6px;
}

.feature-grid,
.question-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin: 18px 0 24px;
}

.feature-card {
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: color-mix(in srgb, var(--surface) 96%, var(--accent-soft));
}

.feature-card h3 {
  margin-top: 0;
}

.feature-card p:last-child {
  margin-bottom: 0;
}

.steps {
  padding-left: 1.6em;
}

.steps li {
  min-height: 44px;
}

.steps li::marker {
  color: var(--accent-strong);
  font-weight: 750;
}

.definition-list {
  display: grid;
  grid-template-columns: minmax(120px, 0.35fr) minmax(0, 1fr);
  margin: 18px 0 24px;
  border-top: 1px solid var(--line);
}

.definition-list dt,
.definition-list dd {
  margin: 0;
  padding: 13px 0;
  border-bottom: 1px solid var(--line);
}

.definition-list dt {
  padding-right: 18px;
  font-weight: 750;
}

.definition-list dd {
  color: var(--muted);
}

.badge {
  display: inline-flex;
  align-items: center;
  padding: 2px 8px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent-strong);
  font-size: 0.82em;
  font-weight: 750;
  vertical-align: 0.08em;
}

.term-note {
  color: var(--muted);
  font-size: 14px;
}

section {
  padding: 28px 0 8px;
  scroll-margin-top: 24px;
}

section + section {
  border-top: 1px solid var(--line);
}

h2 {
  margin: 0 0 16px;
  font-size: 25px;
}

h3 {
  margin: 24px 0 8px;
  font-size: 18px;
}

p {
  margin: 0 0 14px;
}

ul,
ol {
  margin: 10px 0 18px;
  padding-left: 1.4em;
}

li + li {
  margin-top: 8px;
}

.data-table {
  width: 100%;
  margin: 18px 0 22px;
  border-collapse: collapse;
  font-size: 15px;
}

.data-table th,
.data-table td {
  padding: 13px 14px;
  border: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
}

.data-table th {
  background: var(--accent-soft);
  color: var(--accent-strong);
}

.toc {
  grid-column: 2;
  grid-row: 1;
  position: sticky;
  top: 24px;
  max-height: calc(100dvh - 48px);
  overflow-y: auto;
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: var(--surface);
}

.toc strong {
  display: block;
  margin-bottom: 10px;
  font-size: 14px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.toc ol {
  margin: 0;
  padding-left: 1.25em;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.45;
}

.toc li + li {
  margin-top: 8px;
}

.toc a {
  color: inherit;
  text-decoration: none;
}

.toc a:hover {
  color: var(--accent-strong);
  text-decoration: underline;
}

.request-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 18px;
}

.button-link {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  padding: 10px 16px;
  border: 1px solid var(--accent);
  border-radius: 10px;
  background: var(--accent);
  color: #ffffff;
  font-weight: 700;
  text-decoration: none;
}

.button-link.secondary {
  background: transparent;
  color: var(--accent-strong);
}

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 24px;
  padding: 0 0 48px;
  color: var(--muted);
  font-size: 14px;
}

.site-footer p {
  margin: 0;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0d1413;
    --surface: #121c1a;
    --text: #eef7f4;
    --muted: #aebbb7;
    --line: #2b3936;
    --accent: #47b7ac;
    --accent-strong: #75d5cc;
    --accent-soft: #163c38;
    --notice: #132c29;
    --shadow: none;
  }
}

@media (max-width: 860px) {
  .header-inner,
  .header-navs {
    align-items: flex-start;
  }

  .header-navs {
    flex-direction: column;
    gap: 4px;
  }

  .site-nav,
  .language-nav {
    justify-content: flex-start;
  }

  .page-shell {
    display: block;
    padding-top: 28px;
  }

  .toc {
    position: static;
    max-height: min(40dvh, 320px);
    margin-bottom: 20px;
  }

  .document-hero,
  .document-body {
    padding-right: 28px;
    padding-left: 28px;
  }
}

@media (max-width: 560px) {
  .header-inner,
  .site-footer {
    align-items: flex-start;
    flex-direction: column;
  }

  .header-inner {
    padding: 16px 0;
  }

  .language-nav {
    justify-content: flex-start;
  }

  .feature-grid,
  .question-grid {
    grid-template-columns: 1fr;
  }

  .definition-list {
    grid-template-columns: 1fr;
  }

  .definition-list dt {
    padding-bottom: 2px;
    border-bottom: 0;
  }

  .definition-list dd {
    padding-top: 2px;
  }

  .page-shell,
  .header-inner,
  .site-footer {
    width: min(100% - 24px, 1120px);
  }

  .document {
    border-radius: 14px;
  }

  .document-hero,
  .document-body {
    padding-right: 20px;
    padding-left: 20px;
  }

  .document-hero {
    padding-top: 34px;
  }

  .data-table,
  .data-table tbody,
  .data-table tr,
  .data-table th,
  .data-table td {
    display: block;
  }

  .data-table thead {
    position: absolute;
    width: 1px;
    height: 1px;
    overflow: hidden;
    clip: rect(0 0 0 0);
  }

  .data-table tr {
    margin-bottom: 14px;
    border: 1px solid var(--line);
    border-radius: 12px;
    overflow: hidden;
  }

  .data-table td {
    border: 0;
  }

  .data-table td + td {
    border-top: 1px solid var(--line);
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
}

@media print {
  :root {
    color-scheme: light;
    --bg: #ffffff;
    --surface: #ffffff;
    --text: #000000;
    --muted: #333333;
    --line: #cccccc;
    --accent-soft: #f2f2f2;
    --notice: #f7f7f7;
    --shadow: none;
  }

  .site-header,
  .toc,
  .request-links,
  .site-footer {
    display: none;
  }

  .page-shell {
    display: block;
    width: 100%;
    padding: 0;
  }

  .document {
    border: 0;
  }

  .document-hero,
  .document-body {
    padding-right: 0;
    padding-left: 0;
  }

  section {
    break-inside: auto;
  }

  h2,
  h3 {
    break-after: avoid-page;
  }

  p,
  li {
    orphans: 3;
    widows: 3;
  }
}