:root {
  --c-deep-blue: #0A2342;
  --c-mid-blue: #123A6E;
  --c-gold-light: #F2D16B;
  --c-gold-dark: #B8860B;
  --c-cinnabar: #9E2B25;
  --c-cream: #F7F3E8;
  --c-ink: #1A1A1A;
  --c-white: #FFFFFF;
  --c-line: #C9B79C;
  --c-tag: #EAD7C0;
  --f-heading: "Source Han Serif SC", "思源宋体", STSong, serif;
  --f-body: "Source Han Sans SC", "思源黑体", "Helvetica Neue", Arial, sans-serif;
  --f-mono: "JetBrains Mono", "Roboto Mono", Consolas, monospace;
  --rail-width: 260px;
  --border-w: 3px;
  --shadow-hard: 6px 6px 0 rgba(10, 35, 66, 0.18);
  --shadow-soft: 3px 3px 0 rgba(10, 35, 66, 0.1);
  --ease: 0.2s ease;
  --gradient-gold: linear-gradient(135deg, #F2D16B 0%, #B8860B 100%);
  --gradient-blue: linear-gradient(135deg, #123A6E 0%, #0A2342 100%);
}

*, *::before, *::after { box-sizing: border-box; }

body, h1, h2, h3, p, ul, ol, dl, dd, figure, blockquote { margin: 0; padding: 0; }

ul, ol { list-style: none; }

img, svg { max-width: 100%; display: block; }

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

button { font: inherit; color: inherit; background: none; border: none; cursor: pointer; }

html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--f-body);
  font-size: 16px;
  line-height: 1.75;
  color: var(--c-ink);
  background: var(--c-cream);
  min-height: 100vh;
  display: grid;
  grid-template-columns: var(--rail-width) minmax(0, 1fr);
  grid-template-rows: minmax(0, 1fr) auto;
}

:focus-visible {
  outline: 3px solid var(--c-gold-light);
  outline-offset: 2px;
  border-radius: 2px;
}

.skip-link {
  position: fixed;
  top: -56px;
  left: 16px;
  z-index: 2500;
  padding: 12px 20px;
  background: var(--c-cinnabar);
  color: var(--c-white);
  font-weight: 700;
  font-size: 0.9375rem;
  border: 2px solid var(--c-gold-light);
  border-radius: 0 0 6px 6px;
  transition: top var(--ease);
}
.skip-link:focus { top: 0; }

.site-header {
  grid-column: 1;
  grid-row: 1 / -1;
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  min-height: 100vh;
  padding: 32px 24px 28px;
  background: var(--gradient-blue);
  border-right: var(--border-w) solid var(--c-gold-end);
  z-index: 1000;
  overflow: visible;
}
.site-header::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(242, 209, 107, 0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(242, 209, 107, 0.045) 1px, transparent 1px);
  background-size: 28px 28px;
}
.site-header > * { position: relative; }

.brand-block {
  width: 100%;
  padding-bottom: 24px;
  border-bottom: 1px solid rgba(242, 209, 107, 0.22);
}
.brand-lockup {
  display: flex;
  align-items: center;
  gap: 14px;
}
.brand-mark {
  position: relative;
  width: 46px;
  height: 46px;
  flex-shrink: 0;
}
.brand-mark::before {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  width: 28px;
  height: 28px;
  transform: translate(-50%, -50%) rotate(45deg);
  background: var(--gradient-gold);
  border-radius: 4px;
  box-shadow: 0 0 14px rgba(242, 209, 107, 0.25);
}
.brand-mark::after {
  content: "J";
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--f-mono);
  font-size: 24px;
  font-weight: 700;
  color: var(--c-deep-blue);
}
.brand-name {
  font-family: var(--f-heading);
  font-size: 1.5625rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--c-white);
  line-height: 1.2;
}
.brand-tagline {
  margin-top: 12px;
  padding-left: 60px;
  font-family: var(--f-mono);
  font-size: 0.75rem;
  letter-spacing: 0.2em;
  color: var(--c-gold-light);
  opacity: 0.85;
}

.nav-toggle { display: none; }

.site-nav {
  display: flex;
  flex-direction: column;
  flex: 1;
  min-height: 0;
  margin-top: 36px;
  width: 100%;
  align-items: stretch;
}
.nav-list { position: relative; padding-left: 18px; }
.nav-list::before {
  content: "";
  position: absolute;
  left: 0;
  top: 12px;
  bottom: 12px;
  width: 1px;
  background: rgba(242, 209, 107, 0.28);
}
.nav-item { position: relative; }
.nav-item::before {
  content: "";
  position: absolute;
  left: -18px;
  top: 50%;
  width: 14px;
  height: 1px;
  background: rgba(242, 209, 107, 0.28);
  transform: translateY(-50%);
}
.nav-item + .nav-item { margin-top: 6px; }
.nav-link {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 12px 10px 14px;
  border-left: 3px solid transparent;
  color: rgba(255, 255, 255, 0.72);
  border-radius: 0 4px 4px 0;
  transition: color var(--ease), background var(--ease), border-color var(--ease);
}
.nav-link:hover { color: var(--c-white); background: rgba(242, 209, 107, 0.08); }
.nav-link:active { background: rgba(242, 209, 107, 0.14); }
.nav-link[aria-current="page"] {
  border-left-color: var(--c-cinnabar);
  color: var(--c-white);
  background: rgba(158, 43, 37, 0.18);
}
.nav-index {
  font-family: var(--f-mono);
  font-size: 0.75rem;
  letter-spacing: 0.05em;
  color: var(--c-gold-light);
}
.nav-label { font-size: 0.9375rem; font-weight: 500; }

.nav-foot {
  margin-top: auto;
  padding-top: 28px;
  border-top: 1px solid rgba(242, 209, 107, 0.2);
}
.header-slogan {
  font-family: var(--f-heading);
  font-size: 1.0625rem;
  line-height: 1.9;
  letter-spacing: 0.22em;
  color: rgba(255, 255, 255, 0.68);
}
.header-version {
  display: flex;
  flex-direction: column;
  gap: 4px;
  margin-top: 20px;
  padding: 12px 14px;
  border: 2px solid var(--c-gold-dark);
  background: rgba(242, 209, 107, 0.07);
  transition: background var(--ease), border-color var(--ease);
}
.header-version:hover { background: rgba(242, 209, 107, 0.14); border-color: var(--c-gold-light); }
.header-version-label {
  font-family: var(--f-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.15em;
  color: rgba(255, 255, 255, 0.58);
}
.header-version-number {
  font-family: var(--f-mono);
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--c-gold-light);
}
@supports (background-clip: text) or (-webkit-background-clip: text) {
  .header-version-number {
    background-image: var(--gradient-gold);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    color: var(--c-gold-light);
  }
}

#main-content {
  grid-column: 2;
  grid-row: 1;
  min-width: 0;
  padding: 56px 64px;
  background: var(--c-cream);
  scroll-margin-top: 80px;
}
main:focus { outline: none; }

.simple-grid {
  display: grid;
  gap: 24px;
}
.simple-grid-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.simple-grid-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }

main h1, main h2, main h3 {
  font-family: var(--f-heading);
  line-height: 1.4;
  color: var(--c-deep-blue);
}
main h1 { font-size: 2.25rem; font-weight: 900; margin: 0 0 0.6em; letter-spacing: 0.04em; }
main h2 { font-size: 1.75rem; font-weight: 700; margin: 1.6em 0 0.6em; letter-spacing: 0.03em; }
main h3 { font-size: 1.25rem; font-weight: 700; margin: 1.2em 0 0.5em; }
main p { max-width: 60ch; margin-bottom: 1.1em; }

.text-container { max-width: 65ch; }
.text-container p { margin-bottom: 1.2em; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  border: 2px solid var(--c-deep-blue);
  background: transparent;
  color: var(--c-deep-blue);
  font-family: var(--f-body);
  font-size: 1rem;
  font-weight: 700;
  line-height: 1;
  box-shadow: var(--shadow-soft);
  transition: transform var(--ease), box-shadow var(--ease), background var(--ease), color var(--ease);
  text-decoration: none;
}
.btn:hover { transform: translate(-1px, -1px); box-shadow: var(--shadow-hard); }
.btn:active { transform: translate(0, 0); }
.btn-primary { background: var(--c-deep-blue); color: var(--c-white); }
.btn-primary:hover { background: var(--c-mid-blue); color: var(--c-white); }
.btn-gold { background: var(--gradient-gold); color: var(--c-deep-blue); border-color: transparent; }
.btn-gold:hover { color: var(--c-deep-blue); filter: brightness(1.08); }

.breadcrumb { font-family: var(--f-mono); font-size: 0.8125rem; color: var(--c-line); margin-bottom: 32px; }
.breadcrumb ol { display: flex; flex-wrap: wrap; gap: 6px 10px; list-style: none; }
.breadcrumb li { display: flex; align-items: center; gap: 10px; }
.breadcrumb li + li::before { content: "/"; color: var(--c-line); }
.breadcrumb a { color: var(--c-deep-blue); text-decoration: underline; text-underline-offset: 3px; }
.breadcrumb a:hover { color: var(--c-cinnabar); }
.breadcrumb-current { color: var(--c-cinnabar); }

.figure-block {
  border: 2px solid var(--c-deep-blue);
  background: var(--c-tag);
  box-shadow: var(--shadow-hard);
  overflow: hidden;
}
.figure-block img { width: 100%; height: auto; display: block; }
.figure-block figcaption {
  padding: 10px 14px;
  background: var(--c-deep-blue);
  color: var(--c-white);
  font-family: var(--f-mono);
  font-size: 0.8125rem;
}
.figure-block-placeholder {
  aspect-ratio: 16 / 9;
  display: flex;
  align-items: center;
  justify-content: center;
  background:
    repeating-linear-gradient(45deg, rgba(10, 35, 66, 0.045) 0 8px, transparent 8px 16px),
    var(--c-tag);
  color: var(--c-deep-blue);
  font-family: var(--f-mono);
  font-size: 0.75rem;
  letter-spacing: 0.18em;
  text-align: center;
  padding: 16px;
}

.expandable {
  border: 2px solid var(--c-deep-blue);
  background: var(--c-white);
  box-shadow: var(--shadow-soft);
}
.expandable + .expandable { margin-top: 16px; }
.expandable-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  width: 100%;
  padding: 16px 20px;
  text-align: left;
  font-family: var(--f-body);
  font-size: 1.0625rem;
  font-weight: 700;
  color: var(--c-deep-blue);
  background: var(--c-cream);
  border: none;
  cursor: pointer;
  transition: background var(--ease);
}
.expandable-header:hover { background: var(--c-tag); }
.expandable-header::after {
  content: "+";
  font-family: var(--f-mono);
  font-size: 1.375rem;
  color: var(--c-cinnabar);
  line-height: 1;
  transition: transform var(--ease);
  flex-shrink: 0;
}
.expandable[data-expanded="true"] .expandable-header::after { transform: rotate(45deg); }
.expandable-body { display: none; }
.expandable[data-expanded="true"] .expandable-body {
  display: block;
  animation: expand-in var(--ease) both;
}
.expandable-content {
  padding: 4px 20px 20px;
  font-size: 0.9375rem;
  line-height: 1.8;
}
@keyframes expand-in {
  from { opacity: 0; transform: translateY(-4px); }
  to { opacity: 1; transform: translateY(0); }
}

.site-footer {
  grid-column: 2;
  grid-row: 2;
  min-width: 0;
  background: var(--gradient-blue);
  color: var(--c-white);
  border-top: var(--border-w) solid var(--c-gold-end);
}
.footer-inner {
  display: grid;
  grid-template-columns: minmax(0, 1.6fr) minmax(0, 0.8fr) minmax(0, 0.8fr) minmax(0, 1.2fr);
  gap: 40px;
  padding: 48px 56px 28px;
}
.footer-brand { min-width: 0; }
.footer-about {
  font-family: var(--f-heading);
  font-size: 1.125rem;
  line-height: 1.85;
  max-width: 36ch;
  color: rgba(255, 255, 255, 0.9);
}
.footer-trust {
  margin-top: 14px;
  font-family: var(--f-mono);
  font-size: 0.75rem;
  letter-spacing: 0.16em;
  color: var(--c-gold-light);
}
.footer-column { min-width: 0; }
.footer-column-quick,
.footer-column-legal,
.footer-column-contact { min-width: 0; }
.footer-heading {
  font-family: var(--f-mono);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--c-gold-light);
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid rgba(242, 209, 107, 0.25);
}
.footer-list li + li { margin-top: 8px; }
.footer-list a {
  display: inline-block;
  color: rgba(255, 255, 255, 0.75);
  transition: color var(--ease), padding-left var(--ease), border-left-color var(--ease);
}
.footer-list a:hover { color: var(--c-gold-light); }
.footer-list a[aria-current="page"] {
  color: var(--c-gold-light);
  padding-left: 10px;
  border-left: 2px solid var(--c-cinnabar);
}
.footer-contact-line { font-size: 0.875rem; line-height: 1.7; color: rgba(255, 255, 255, 0.75); }
.footer-contact-line + .footer-contact-line { margin-top: 6px; }
.footer-meta {
  grid-column: 1 / -1;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 8px 24px;
  padding-top: 20px;
  border-top: 1px solid rgba(255, 255, 255, 0.14);
  font-family: var(--f-mono);
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  color: rgba(255, 255, 255, 0.52);
}

.version-chip {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 1100;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 10px 16px;
  background: var(--gradient-gold);
  color: var(--c-deep-blue);
  font-family: var(--f-mono);
  font-weight: 700;
  font-size: 0.875rem;
  line-height: 1;
  border: 2px solid var(--c-deep-blue);
  box-shadow: 4px 4px 0 rgba(10, 35, 66, 0.4);
  transition: transform var(--ease), box-shadow var(--ease);
}
.version-chip:hover { transform: translate(-2px, -2px); box-shadow: 6px 6px 0 rgba(10, 35, 66, 0.4); }
.version-chip:active { transform: translate(0, 0); box-shadow: 2px 2px 0 rgba(10, 35, 66, 0.4); }
.version-chip-icon { font-size: 1rem; line-height: 1; }

@media (max-width: 960px) {
  body { display: block; }

  .site-header {
    position: sticky;
    top: 0;
    display: flex;
    flex-direction: row;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    min-height: 0;
    padding: 10px 16px;
    border-right: none;
    border-bottom: var(--border-w) solid var(--c-gold-end);
    z-index: 1200;
  }

  .brand-block { padding: 0; border: none; width: auto; }
  .brand-lockup { gap: 10px; }
  .brand-mark { width: 36px; height: 36px; }
  .brand-mark::before { width: 22px; height: 22px; }
  .brand-mark::after { font-size: 18px; }
  .brand-name { font-size: 1.25rem; letter-spacing: 0.1em; }
  .brand-tagline { display: none; }

  .nav-toggle {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 10px;
    border: 2px solid var(--c-gold-dark);
    color: var(--c-white);
    font-size: 0.8125rem;
    line-height: 1;
    background: transparent;
    transition: border-color var(--ease), background var(--ease);
  }
  .nav-toggle:hover { border-color: var(--c-gold-light); background: rgba(242, 209, 107, 0.08); }
  .nav-toggle-bars { display: flex; flex-direction: column; gap: 5px; }
  .nav-toggle-bar {
    display: block;
    width: 20px;
    height: 2px;
    background: currentColor;
    transition: transform var(--ease), opacity var(--ease);
  }
  .nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(1) { transform: translateY(7px) rotate(45deg); }
  .nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(2) { opacity: 0; }
  .nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    width: auto;
    flex: none;
    margin-top: 0;
    padding: 20px;
    background: var(--c-deep-blue);
    border-bottom: var(--border-w) solid var(--c-gold-dark);
    box-shadow: 0 12px 24px rgba(0, 0, 0, 0.35);
    max-height: calc(100vh - 68px);
    overflow-y: auto;
    visibility: hidden;
    opacity: 0;
    transform: translateY(-6px);
    transition: opacity var(--ease), transform var(--ease), visibility var(--ease);
  }
  .site-nav[data-open] {
    visibility: visible;
    opacity: 1;
    transform: translateY(0);
  }

  .nav-foot { margin-top: 24px; }

  #main-content { padding: 36px 28px; }

  .simple-grid-2 { grid-template-columns: 1fr; }
  .simple-grid-3 { grid-template-columns: 1fr; }

  .footer-inner {
    grid-template-columns: 1fr 1fr;
    gap: 32px;
    padding: 36px 28px 24px;
  }
  .footer-brand { grid-column: 1 / -1; }
  .footer-column-contact { grid-column: 1 / -1; }
  .footer-meta { grid-column: 1 / -1; }

  .version-chip {
    bottom: 16px;
    right: 16px;
    padding: 8px 12px;
    font-size: 0.75rem;
    box-shadow: 3px 3px 0 rgba(10, 35, 66, 0.4);
  }
  .version-chip-icon { display: none; }
}

@media (max-width: 640px) {
  .nav-toggle-label { display: none; }
  #main-content { padding: 28px 20px; }
  .footer-inner { grid-template-columns: 1fr; padding: 32px 20px 20px; }
  .footer-brand,
  .footer-column-contact,
  .footer-meta { grid-column: 1; }
  main h1 { font-size: 1.875rem; }
  main h2 { font-size: 1.5rem; }
  main h3 { font-size: 1.125rem; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}