:root {
  --deep-blue: #0A1B2E;
  --royal-gold: #C9A36A;
  --dark-gold: #8C6B3F;
  --vermilion: #D9364D;
  --white: #FFFFFF;
  --cloud: #F2F4F7;
  --mist: #6B7280;
  --wheat: #EBD9B4;
  --font-display: Georgia, 'Times New Roman', 'Noto Serif SC', serif;
  --font-body: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Noto Sans SC', sans-serif;
  --font-mono: 'SF Mono', 'Roboto Mono', 'Fira Mono', monospace;
  --content-width: 1200px;
  --text-color: #1F2937;
  --border-color: #E5E7EB;
  --footer-bg: #071524;
}

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

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

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

body {
  margin: 0;
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  color: var(--text-color);
  background: var(--white);
}

#main-content {
  min-height: 60vh;
  display: block;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

ul,
ol {
  margin: 0;
  padding: 0;
  list-style: none;
}

h1,
h2,
h3,
h4 {
  font-family: var(--font-display);
  margin: 0 0 0.5em;
  line-height: 1.3;
  color: var(--deep-blue);
}

p {
  margin: 0 0 1em;
}

a {
  color: var(--dark-gold);
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  color: var(--royal-gold);
}

:focus-visible {
  outline: 2px solid var(--royal-gold);
  outline-offset: 3px;
}

.skip-link {
  position: fixed;
  top: -100px;
  left: 16px;
  z-index: 220;
  background: var(--royal-gold);
  color: var(--deep-blue);
  font-weight: 600;
  font-size: 14px;
  padding: 10px 18px;
  border-radius: 0 0 4px 4px;
  transition: top 0.2s ease;
}

.skip-link:focus {
  top: 0;
}

.container {
  width: min(var(--content-width), 100% - 32px);
  margin-inline: auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--deep-blue);
  color: var(--white);
  border-bottom: 1px solid rgba(201, 163, 106, 0.35);
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.18);
}

.scroll-progress {
  position: absolute;
  top: 0;
  left: 0;
  height: 3px;
  width: 0%;
  background: linear-gradient(90deg, var(--royal-gold), var(--wheat));
  z-index: 10;
  pointer-events: none;
}

.site-header__inner {
  width: min(var(--content-width), 100% - 32px);
  margin-inline: auto;
}

.masthead {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  padding-top: 22px;
}

.masthead__meta {
  justify-self: start;
  display: flex;
  flex-direction: column;
  font-family: var(--font-mono);
  font-size: 11px;
  line-height: 1.6;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.55);
}

.masthead__brand {
  text-align: center;
}

.masthead__brand-name {
  display: block;
  font-family: var(--font-display);
  font-size: 38px;
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: 0.08em;
  color: var(--white);
}

.masthead__tagline {
  margin: 6px 0 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--royal-gold);
  text-transform: uppercase;
}

.masthead__actions {
  justify-self: end;
  display: flex;
  align-items: center;
  gap: 16px;
}

.masthead__edition {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  font-family: var(--font-mono);
  font-size: 11px;
  line-height: 1.6;
  letter-spacing: 0.1em;
  color: rgba(255, 255, 255, 0.55);
  text-transform: uppercase;
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 8px;
  background: transparent;
  border: 1px solid rgba(201, 163, 106, 0.5);
  color: var(--royal-gold);
  padding: 6px 14px;
  font-family: var(--font-body);
  font-size: 13px;
  cursor: pointer;
  transition: background 0.2s ease, border-color 0.2s ease;
}

.nav-toggle:hover {
  background: rgba(201, 163, 106, 0.12);
  border-color: var(--royal-gold);
}

.nav-toggle__icon {
  display: flex;
  flex-direction: column;
  gap: 3px;
}

.nav-toggle__line {
  display: block;
  width: 16px;
  height: 2px;
  background: currentColor;
}

.nav-toggle__label {
  font-size: 12px;
  letter-spacing: 0.12em;
}

.masthead__divider {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-top: 12px;
}

.masthead__divider-line {
  flex: 1;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(201, 163, 106, 0.55), transparent);
}

.masthead__divider-diamond {
  width: 6px;
  height: 6px;
  background: var(--royal-gold);
  transform: rotate(45deg);
  flex-shrink: 0;
}

.site-nav {
  padding-bottom: 14px;
}

.site-nav__list {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 4px 32px;
}

.site-nav__link {
  position: relative;
  display: inline-block;
  padding: 10px 2px 8px;
  font-size: 15px;
  letter-spacing: 0.08em;
  color: rgba(255, 255, 255, 0.85);
  transition: color 0.2s ease;
}

.site-nav__link::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  height: 2px;
  background: var(--royal-gold);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 0.25s ease;
}

.site-nav__link:hover,
.site-nav__link:focus-visible {
  color: var(--royal-gold);
}

.site-nav__link:hover::after,
.site-nav__link:focus-visible::after,
.site-nav__link[aria-current="page"]::after {
  transform: scaleX(1);
}

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

.site-footer {
  background: var(--footer-bg);
  color: rgba(255, 255, 255, 0.75);
  border-top: 4px solid var(--royal-gold);
  margin-top: 80px;
  position: relative;
}

.site-footer__inner {
  width: min(var(--content-width), 100% - 32px);
  margin-inline: auto;
  padding: 48px 0 24px;
}

.site-footer__top {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 40px;
  align-items: start;
  padding-bottom: 36px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.site-footer__name {
  display: block;
  font-family: var(--font-display);
  font-size: 30px;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--white);
  line-height: 1.2;
}

.site-footer__desc {
  margin: 8px 0 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--royal-gold);
  text-transform: uppercase;
}

.site-footer__statement {
  margin: 0;
  font-size: 14px;
  line-height: 1.9;
  color: rgba(255, 255, 255, 0.65);
  border-left: 3px solid var(--royal-gold);
  padding-left: 18px;
}

.site-footer__middle {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 40px;
  padding: 36px 0 40px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.site-footer__title {
  margin: 0 0 16px;
  padding-bottom: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 400;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--royal-gold);
  border-bottom: 1px solid rgba(201, 163, 106, 0.25);
}

.site-footer__list li {
  margin-bottom: 8px;
  font-size: 14px;
  line-height: 1.6;
}

.site-footer__list a {
  color: rgba(255, 255, 255, 0.75);
  transition: color 0.2s ease;
}

.site-footer__list a:hover {
  color: var(--royal-gold);
}

.site-footer__bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  padding-top: 20px;
  font-size: 13px;
  color: rgba(255, 255, 255, 0.45);
  font-family: var(--font-mono);
}

.site-footer__icp {
  letter-spacing: 0.04em;
}

.back-to-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  z-index: 90;
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--deep-blue);
  border: 1px solid var(--royal-gold);
  color: var(--royal-gold);
  font-size: 18px;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  clip-path: polygon(8px 0, calc(100% - 8px) 0, 100% 8px, 100% calc(100% - 8px), calc(100% - 8px) 100%, 8px 100%, 0 calc(100% - 8px), 0 8px);
  transition: opacity 0.25s ease, transform 0.25s ease, visibility 0.25s ease, background 0.2s ease, color 0.2s ease;
}

.back-to-top[data-shown] {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  background: var(--royal-gold);
  color: var(--deep-blue);
}

.section {
  padding: 48px 0;
}

.section-heading {
  display: flex;
  align-items: baseline;
  gap: 14px;
  margin-bottom: 28px;
}

.section-heading__index {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--royal-gold);
  letter-spacing: 0.08em;
  white-space: nowrap;
}

.section-heading__index::before {
  content: '';
  display: inline-block;
  width: 12px;
  height: 2px;
  background: var(--royal-gold);
  transform: skewX(-30deg);
  margin-right: 8px;
  vertical-align: middle;
}

.section-heading__title {
  font-family: var(--font-display);
  font-size: 28px;
  color: var(--deep-blue);
  margin: 0;
  letter-spacing: 0.02em;
}

.section-heading__rule {
  flex: 1;
  height: 1px;
  background: linear-gradient(90deg, rgba(201, 163, 106, 0.45), transparent);
  min-width: 40px;
}

.prose {
  max-width: 720px;
}

.prose p {
  margin-bottom: 16px;
  line-height: 1.9;
}

.prose h2 {
  font-size: 24px;
  margin-top: 36px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-color);
}

.prose h3 {
  font-size: 18px;
  margin-top: 24px;
}

.prose ul {
  list-style: disc;
  padding-left: 20px;
  margin-bottom: 16px;
}

.prose ol {
  list-style: decimal;
  padding-left: 20px;
  margin-bottom: 16px;
}

.prose li {
  margin-bottom: 6px;
}

.grid {
  display: grid;
  gap: 24px;
}

.grid--2 {
  grid-template-columns: repeat(2, 1fr);
}

.grid--3 {
  grid-template-columns: repeat(3, 1fr);
}

.panel {
  position: relative;
  background: var(--cloud);
  border: 1px solid var(--border-color);
  padding: 28px;
}

.panel::before {
  content: '';
  position: absolute;
  top: -1px;
  right: -1px;
  width: 0;
  height: 0;
  border-top: 14px solid var(--royal-gold);
  border-left: 14px solid transparent;
}

.card {
  background: var(--white);
  border: 1px solid var(--border-color);
  border-left: 3px solid var(--royal-gold);
  padding: 24px;
  transition: box-shadow 0.2s ease, transform 0.2s ease;
}

.card:hover {
  box-shadow: 0 8px 24px rgba(10, 27, 46, 0.08);
  transform: translateY(-2px);
}

.tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  background: var(--cloud);
  border: 1px solid var(--border-color);
  color: var(--mist);
  padding: 3px 10px;
  text-transform: uppercase;
}

.tag--gold {
  background: var(--wheat);
  color: var(--dark-gold);
  border-color: transparent;
}

.tag--red {
  background: rgba(217, 54, 77, 0.12);
  color: var(--vermilion);
  border-color: transparent;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--royal-gold);
  color: var(--deep-blue);
  border: 1px solid var(--royal-gold);
  padding: 10px 28px;
  font-family: var(--font-body);
  font-size: 15px;
  font-weight: 600;
  line-height: 1.4;
  cursor: pointer;
  text-decoration: none;
  transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.btn:hover {
  background: var(--dark-gold);
  border-color: var(--dark-gold);
  color: var(--white);
}

.btn--ghost {
  background: transparent;
  color: var(--royal-gold);
}

.btn--ghost:hover {
  background: rgba(201, 163, 106, 0.1);
  border-color: var(--royal-gold);
  color: var(--royal-gold);
}

.btn--sm {
  padding: 6px 16px;
  font-size: 13px;
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--mist);
  padding: 16px 0;
}

.breadcrumb a {
  color: var(--dark-gold);
}

.breadcrumb a:hover {
  color: var(--deep-blue);
}

.breadcrumb__sep {
  color: rgba(107, 114, 128, 0.5);
}

.figure-container {
  position: relative;
  background: var(--cloud);
  border: 1px solid var(--border-color);
  overflow: hidden;
}

.figure-container--wide {
  aspect-ratio: 16 / 9;
}

.figure-container--tall {
  aspect-ratio: 4 / 5;
}

.note {
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.7;
  color: var(--mist);
  border-left: 3px solid var(--royal-gold);
  padding: 8px 0 8px 16px;
}

.divider {
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--royal-gold);
  letter-spacing: 0.1em;
}

.divider::before,
.divider::after {
  content: '';
  flex: 1;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(201, 163, 106, 0.4), transparent);
}

@media (max-width: 992px) {
  .site-footer__top {
    grid-template-columns: 1fr;
  }

  .site-footer__middle {
    grid-template-columns: repeat(2, 1fr);
  }

  .grid--3 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .site-header__inner {
    width: min(100% - 24px, var(--content-width));
  }

  .masthead {
    grid-template-columns: 1fr auto;
    padding-top: 14px;
  }

  .masthead__meta,
  .masthead__edition {
    display: none;
  }

  .masthead__brand {
    text-align: left;
  }

  .masthead__brand-name {
    font-size: 24px;
  }

  .masthead__tagline {
    font-size: 10px;
    letter-spacing: 0.1em;
    margin-top: 3px;
  }

  .masthead__actions {
    justify-self: end;
  }

  .nav-toggle {
    display: inline-flex;
  }

  .masthead__divider {
    display: none;
  }

  .site-nav {
    padding-bottom: 0;
  }

  .site-nav__list {
    display: none;
    flex-direction: column;
    gap: 0;
    padding: 0 0 14px;
    border-top: 1px solid rgba(201, 163, 106, 0.25);
    margin-top: 8px;
  }

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

  .site-nav__link {
    display: block;
    padding: 12px 4px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    font-size: 15px;
  }

  .site-nav__link::after {
    display: none;
  }

  .site-footer__inner {
    width: min(100% - 24px, var(--content-width));
    padding-top: 36px;
  }

  .site-footer__middle {
    grid-template-columns: 1fr;
    gap: 28px;
    padding: 28px 0 20px;
  }

  .site-footer__bottom {
    flex-direction: column;
    text-align: center;
  }

  .back-to-top {
    right: 16px;
    bottom: 16px;
    width: 40px;
    height: 40px;
  }

  .section {
    padding: 32px 0;
  }

  .section-heading {
    flex-wrap: wrap;
    gap: 8px 12px;
  }

  .section-heading__title {
    font-size: 22px;
  }

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

  .panel,
  .card {
    padding: 20px;
  }
}

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