:root {
  --ink: #0A0A0A;
  --paper: #F5F5F0;
  --royal: #003366;
  --gold: #FFD700;
  --crimson: #8B0000;
  --gray-800: #1A1A1A;
  --gray-200: #E0E0E0;
  --white: #FFFFFF;
  --soft-blue: #E6F0FF;
  --font-sans: "Inter", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", "Segoe UI", sans-serif;
  --font-mono: "Roboto Mono", "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  --site-max: 1240px;
  --gutter: clamp(1.25rem, 4vw, 3.5rem);
  --header-h: 84px;
}

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

html {
  -webkit-text-size-adjust: 100%;
  line-height: 1.5;
}

body {
  margin: 0;
  min-height: 100vh;
  padding-top: var(--header-h);
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-sans);
  line-height: 1.625;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

body.nav-open {
  overflow: hidden;
}

h1, h2, h3, h4, p, ul, ol, dl, dd, figure, blockquote {
  margin: 0;
  padding: 0;
}

ul[class] {
  list-style: none;
}

a {
  color: inherit;
}

button {
  font: inherit;
  cursor: pointer;
}

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

[hidden] {
  display: none !important;
}

:focus-visible {
  outline: 3px solid var(--gold);
  outline-offset: 3px;
}

::selection {
  background: var(--royal);
  color: var(--paper);
}

@media (prefers-reduced-motion: no-preference) {
  html {
    scroll-behavior: smooth;
  }
}

.site-header {
  --header-bg: transparent;
  --header-fg: var(--ink);
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: var(--header-bg);
  color: var(--header-fg);
  box-shadow: inset 0 4px 0 var(--royal);
  transition: background-color 0.3s ease, box-shadow 0.3s ease, color 0.3s ease;
}

.site-header.is-sunken {
  --header-bg: var(--paper);
  --header-fg: var(--ink);
  box-shadow: inset 0 4px 0 var(--royal), 0 2px 0 var(--ink), 0 12px 30px rgba(0, 0, 0, 0.16);
}

.site-header__inner {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  gap: 1rem;
  width: 100%;
  max-width: var(--site-max);
  min-height: var(--header-h);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.site-header__progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 2;
  height: 4px;
  background: var(--gold);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 0.12s linear;
}

.site-header__brand {
  display: inline-flex;
  align-items: center;
  gap: 0.8rem;
  color: inherit;
  text-decoration: none;
}

.site-header__brand:hover .site-mark {
  background: var(--ink);
  color: var(--gold);
}

.site-mark {
  display: grid;
  place-items: center;
  width: 2.75rem;
  height: 2.75rem;
  background: var(--royal);
  color: var(--gold);
  border: 2px solid var(--ink);
  box-shadow: 3px 3px 0 var(--ink);
  font-family: var(--font-mono);
  font-size: 1.35rem;
  font-weight: 800;
  line-height: 1;
  transition: background-color 0.2s ease, color 0.2s ease, box-shadow 0.2s ease;
}

.site-wordmark {
  display: inline-grid;
  gap: 0.12rem;
}

.site-wordmark__cn {
  font-size: 1.15rem;
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: 0.1em;
}

.site-wordmark__sub {
  font-family: var(--font-mono);
  font-size: 0.6rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--royal);
}

.site-nav {
  margin-inline: auto;
}

.site-nav__list {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.site-nav__link {
  display: block;
  padding: 0.8rem 0.9rem;
  color: inherit;
  text-decoration: none;
  font-weight: 700;
  border-bottom: 3px solid transparent;
  transition: color 0.2s ease, border-color 0.2s ease;
}

.site-nav__link:hover {
  color: var(--royal);
  border-bottom-color: var(--gold);
}

.site-nav__link[aria-current="page"] {
  color: var(--royal);
  border-bottom-color: var(--royal);
}

.site-header__actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.site-header__toggle {
  display: none;
  align-items: center;
  justify-content: center;
  gap: 4px;
  width: 2.75rem;
  height: 2.75rem;
  padding: 0.5rem;
  border: 2px solid var(--ink);
  background: var(--paper);
  color: var(--ink);
  box-shadow: 3px 3px 0 var(--ink);
  transition: background-color 0.2s ease, color 0.2s ease, box-shadow 0.2s ease;
}

.site-header__toggle:hover {
  background: var(--royal);
  color: var(--gold);
  box-shadow: 1px 1px 0 var(--ink);
}

.site-header__toggle[aria-expanded="true"] {
  background: var(--ink);
  color: var(--gold);
  box-shadow: 2px 2px 0 var(--gold);
}

.site-header__toggle-bar {
  display: block;
  width: 1.25rem;
  height: 2px;
  background: currentColor;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.site-header__toggle[aria-expanded="true"] .site-header__toggle-bar:nth-child(1) {
  transform: translateY(6px) rotate(45deg);
}

.site-header__toggle[aria-expanded="true"] .site-header__toggle-bar:nth-child(2) {
  opacity: 0;
}

.site-header__toggle[aria-expanded="true"] .site-header__toggle-bar:nth-child(3) {
  transform: translateY(-6px) rotate(-45deg);
}

.skip-link {
  position: fixed;
  top: -100%;
  left: 1rem;
  z-index: 2000;
  padding: 0.8rem 1.2rem;
  background: var(--royal);
  color: var(--paper);
  font-weight: 700;
  text-decoration: none;
  border: 2px solid var(--ink);
  box-shadow: 4px 4px 0 var(--gold);
}

.skip-link:focus {
  top: 1rem;
}

#main-content {
  scroll-margin-top: calc(var(--header-h) + 0.5rem);
}

#main-content:focus {
  outline: none;
}

.site-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.1rem;
  border: 2px solid var(--ink);
  background: var(--paper);
  color: var(--ink);
  font-weight: 700;
  text-decoration: none;
  box-shadow: 4px 4px 0 var(--ink);
  transition: transform 0.12s ease, box-shadow 0.12s ease, background-color 0.2s ease, color 0.2s ease;
}

.site-btn:hover {
  transform: translate(2px, 2px);
  box-shadow: 2px 2px 0 var(--ink);
  background: var(--white);
}

.site-btn:active {
  transform: translate(4px, 4px);
  box-shadow: 0 0 0 var(--ink);
}

.site-btn--primary {
  background: var(--royal);
  color: var(--paper);
  box-shadow: 4px 4px 0 var(--gold);
}

.site-btn--primary:hover {
  background: var(--ink);
  color: var(--gold);
  box-shadow: 2px 2px 0 var(--gold);
}

.site-footer {
  background: var(--ink);
  color: var(--paper);
  border-top: 6px solid var(--royal);
}

.site-footer__ornament {
  display: flex;
  gap: 0.75rem;
  width: 100%;
  max-width: var(--site-max);
  margin-inline: auto;
  padding: 1.5rem var(--gutter) 0;
}

.site-footer__ornament-bar {
  display: block;
  width: 3rem;
  height: 0.5rem;
  transform: skewX(-20deg);
}

.site-footer__ornament-bar:nth-child(1) {
  background: var(--gold);
}

.site-footer__ornament-bar:nth-child(2) {
  width: 6rem;
  background: var(--royal);
}

.site-footer__ornament-bar:nth-child(3) {
  background: var(--crimson);
}

.site-footer__wrap {
  width: 100%;
  max-width: var(--site-max);
  margin-inline: auto;
  padding: var(--gutter);
}

.site-footer__grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 0.75fr;
  gap: clamp(2rem, 4vw, 3.5rem);
  padding-bottom: 2rem;
}

.site-footer__brand-link {
  display: inline-flex;
  align-items: center;
  gap: 0.9rem;
  color: var(--paper);
  text-decoration: none;
}

.site-footer .site-mark {
  border-color: var(--gold);
  box-shadow: 4px 4px 0 var(--gold);
}

.site-footer__word {
  display: grid;
  gap: 0.1rem;
}

.site-footer__word strong {
  font-size: 1.05rem;
  letter-spacing: 0.08em;
}

.site-footer__word span {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--gold);
}

.site-footer__statement {
  margin-top: 1.5rem;
  max-width: 36rem;
  padding-left: 1rem;
  border-left: 4px solid var(--royal);
  color: #C9C9C9;
  font-size: 0.95rem;
}

.site-footer__title {
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--gray-800);
  font-size: 0.8rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--gold);
}

.site-footer__list {
  display: grid;
  gap: 0.55rem;
  color: #D8D8D8;
  font-size: 0.95rem;
}

.site-footer__list--links a {
  color: var(--paper);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.2s ease, border-color 0.2s ease;
}

.site-footer__list--links a:hover {
  color: var(--gold);
  border-bottom-color: var(--gold);
}

.site-footer__note {
  margin-top: 1rem;
  padding-left: 0.75rem;
  border-left: 4px solid var(--crimson);
  color: #9A9A9A;
  font-size: 0.85rem;
  line-height: 1.7;
}

.site-footer__bottom {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 1rem;
  margin-top: 1rem;
  padding-top: 1.25rem;
  border-top: 2px solid var(--gray-800);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  color: #9A9A9A;
}

.container {
  width: 100%;
  max-width: var(--site-max);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section {
  padding-block: clamp(3rem, 8vw, 6rem);
}

.section-header {
  display: grid;
  grid-template-columns: auto 1fr;
  align-items: end;
  gap: 1rem;
  margin-bottom: clamp(2rem, 5vw, 4rem);
}

.section-index {
  color: var(--royal);
  opacity: 0.16;
  font-family: var(--font-mono);
  font-size: clamp(4rem, 12vw, 8rem);
  line-height: 0.8;
  font-weight: 800;
  letter-spacing: -0.08em;
}

.section-kicker {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--royal);
}

.section-kicker::before {
  content: "";
  width: 2rem;
  height: 2px;
  background: var(--gold);
}

.section-title {
  margin-top: 0.5rem;
  font-size: clamp(2rem, 5vw, 3.5rem);
  line-height: 1.05;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.lead {
  max-width: 62ch;
  font-size: clamp(1.05rem, 1.4vw, 1.25rem);
  color: var(--gray-800);
}

.grid {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 1.5rem;
}

.grid__item {
  grid-column: span 12;
}

.grid__item--span-3 {
  grid-column: span 12;
}

.grid__item--span-4 {
  grid-column: span 12;
}

.grid__item--span-6 {
  grid-column: span 12;
}

.panel {
  padding: clamp(1.25rem, 3vw, 2rem);
  background: var(--white);
  border: 2px solid var(--ink);
  box-shadow: 8px 8px 0 rgba(0, 0, 0, 0.15);
}

.panel--ink {
  background: var(--ink);
  color: var(--paper);
  box-shadow: 8px 8px 0 var(--royal);
}

.panel--royal {
  background: var(--royal);
  color: var(--paper);
  border-color: var(--ink);
  box-shadow: 8px 8px 0 var(--gold);
}

.panel--royal .section-kicker {
  color: var(--gold);
}

.panel--royal .lead {
  color: #DDE8F5;
}

.divider {
  display: block;
  width: 100%;
  height: 6px;
  margin: 2rem 0;
  border: 0;
  background: linear-gradient(90deg, var(--royal) 0 33%, var(--gold) 33% 66%, var(--crimson) 66% 100%);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.25rem 0.65rem;
  background: var(--soft-blue);
  color: var(--royal);
  border: 1px solid var(--royal);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
}

.tag--alert {
  background: var(--crimson);
  color: var(--paper);
  border-color: var(--crimson);
}

.notice {
  padding: 1rem 1.25rem;
  background: var(--paper);
  border: 2px solid var(--crimson);
  color: var(--crimson);
  font-weight: 700;
  box-shadow: 4px 4px 0 rgba(139, 0, 0, 0.18);
}

.breadcrumb {
  padding-block: 1.25rem;
  font-family: var(--font-mono);
  font-size: 0.8rem;
}

.breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  list-style: none;
}

.breadcrumb__item {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--gray-800);
}

.breadcrumb__item[aria-current="page"] {
  color: var(--royal);
  font-weight: 700;
}

.breadcrumb__link {
  color: inherit;
  text-decoration: none;
}

.breadcrumb__link:hover {
  color: var(--royal);
}

.breadcrumb__sep {
  color: var(--gold);
}

.prose {
  max-width: 70ch;
  font-size: 1.0625rem;
  line-height: 1.8;
  color: var(--gray-800);
}

.prose h2 {
  margin-top: 2.5em;
  margin-bottom: 0.8em;
  font-size: 1.6rem;
  line-height: 1.2;
  color: var(--ink);
}

.prose h3 {
  margin-top: 2em;
  margin-bottom: 0.6em;
  font-size: 1.2rem;
  color: var(--royal);
}

.prose p {
  margin-bottom: 1.25em;
}

.prose a {
  color: var(--royal);
  text-decoration-thickness: 2px;
  text-underline-offset: 4px;
}

.prose a:hover {
  color: var(--crimson);
}

.prose ul,
.prose ol {
  margin: 0 0 1.25em;
  padding-left: 1.3rem;
}

.media {
  position: relative;
  overflow: hidden;
  background: var(--soft-blue);
  border: 2px solid var(--ink);
  box-shadow: 8px 8px 0 rgba(0, 0, 0, 0.18);
}

.media--ratio-16x9::before,
.media--ratio-4x3::before {
  content: "";
  display: block;
}

.media--ratio-16x9::before {
  padding-top: 56.25%;
}

.media--ratio-4x3::before {
  padding-top: 75%;
}

.media > img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media__placeholder {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--royal);
}

.media__placeholder::before {
  content: "◆";
  font-size: 1.5rem;
  color: var(--gold);
}

.tablist {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  position: relative;
  z-index: 1;
  margin-bottom: -2px;
  padding-left: 0.25rem;
  border-bottom: 2px solid var(--ink);
}

.tab {
  appearance: none;
  padding: 0.6rem 1rem;
  border: 2px solid var(--ink);
  background: var(--paper);
  color: var(--ink);
  font-weight: 700;
  box-shadow: 3px 3px 0 var(--ink);
  transition: background-color 0.2s ease, color 0.2s ease, box-shadow 0.2s ease;
}

.tab:hover {
  background: var(--white);
}

.tab[aria-selected="true"] {
  background: var(--royal);
  color: var(--paper);
  border-color: var(--royal);
  box-shadow: 3px 3px 0 var(--gold);
}

.tabpanel {
  padding: clamp(1rem, 3vw, 2rem);
  background: var(--white);
  border: 2px solid var(--ink);
  box-shadow: 8px 8px 0 var(--gray-200);
}

.tabpanel:focus {
  outline: 3px solid var(--gold);
  outline-offset: -3px;
}

@media (min-width: 700px) {
  .grid__item--span-3 {
    grid-column: span 3;
  }

  .grid__item--span-4 {
    grid-column: span 4;
  }

  .grid__item--span-6 {
    grid-column: span 6;
  }
}

@media (min-width: 901px) and (max-width: 1100px) {
  .site-nav__link {
    padding: 0.8rem 0.65rem;
    font-size: 0.95rem;
  }

  .site-wordmark__sub {
    display: none;
  }
}

@media (max-width: 900px) {
  :root {
    --header-h: 72px;
  }

  .site-header__toggle {
    display: flex;
  }

  .site-header__inner {
    flex-wrap: wrap;
  }

  .site-header__brand {
    margin-right: auto;
  }

  .site-header__actions {
    margin-left: auto;
  }

  .site-nav {
    position: fixed;
    top: var(--header-h);
    right: 0;
    left: 0;
    bottom: 0;
    z-index: 999;
    display: none;
    flex-direction: column;
    padding: 1.5rem var(--gutter) 3rem;
    overflow-y: auto;
    background: var(--paper);
    box-shadow: inset 0 4px 0 var(--royal);
  }

  .site-nav[data-open] {
    display: flex;
  }

  .site-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }

  .site-nav__link {
    padding: 1rem 0;
    border-bottom: 1px solid var(--gray-200);
    font-size: 1.25rem;
  }

  .site-nav__link:hover,
  .site-nav__link[aria-current="page"] {
    border-bottom-color: var(--royal);
  }

  .site-wordmark__sub {
    display: none;
  }

  .site-btn {
    padding: 0.6rem 0.85rem;
    font-size: 0.9rem;
  }

  .site-footer__grid {
    grid-template-columns: 1fr 1fr;
  }

  .site-footer__brand {
    grid-column: 1 / -1;
  }
}

@media (max-width: 560px) {
  .site-header__actions .site-btn {
    padding: 0.5rem 0.7rem;
    font-size: 0.85rem;
  }

  .site-wordmark__cn {
    font-size: 0.95rem;
  }

  .site-footer__grid {
    grid-template-columns: 1fr;
  }

  .site-footer__bottom {
    flex-direction: column;
  }

  .section-header {
    grid-template-columns: 1fr;
    gap: 0.5rem;
  }
}

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

  .site-header__progress {
    transition: none;
  }
}