@font-face {
  font-family: 'Centra';
  src: url('/assets/fonts/CentraNo2-Book.woff2') format('woff2');
  font-weight: 400;
  font-display: swap;
}

@font-face {
  font-family: 'Centra';
  src: url('/assets/fonts/CentraNo2-Medium.woff2') format('woff2');
  font-weight: 600;
  font-display: swap;
}

@font-face {
  font-family: 'Centra Mono';
  src: url('/assets/fonts/CentraMono-Book.woff2') format('woff2');
  font-display: swap;
}

@font-face {
  font-family: 'GT Canon';
  src: url('/assets/fonts/GTCanonS-Regular.woff2') format('woff2');
  font-display: swap;
}

:root {
  color-scheme: light;
  --ledger: #0a2a4c;
  --ledger-soft: #11457c;
  --signal: #2762a5;
  --signal-bright: #3d8bd8;
  --signal-pale: #e7f0fa;
  --gold: #e8ad39;
  --ink: #172433;
  --ink-soft: #526274;
  --paper: #ffffff;
  --field: #f4f7fa;
  --rule: #dbe4ec;
  --code: #eef3f7;
  --shadow: 0 26px 80px rgba(10, 42, 76, 0.15);
  font-family: 'Centra', system-ui, sans-serif;
  background: var(--paper);
  color: var(--ink);
  font-synthesis: none;
}

:root[data-theme='dark'] {
  color-scheme: dark;
  --ledger: #9dccff;
  --ledger-soft: #80b6ee;
  --signal: #65a8e8;
  --signal-bright: #8fc9ff;
  --signal-pale: #173652;
  --gold: #f0bf5e;
  --ink: #edf4fa;
  --ink-soft: #aabaca;
  --paper: #0b1722;
  --field: #101f2d;
  --rule: #263b4d;
  --code: #152a3b;
  --shadow: 0 26px 80px rgba(0, 0, 0, 0.42);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--paper); color: var(--ink); }
a { color: inherit; }
button, input { font: inherit; }
button { color: inherit; }
svg { display: block; }
::selection { background: var(--signal-pale); color: var(--ledger); }

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
}

.skip-link {
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 100;
  padding: 10px 14px;
  border-radius: 6px;
  background: var(--paper);
  color: var(--ledger);
  box-shadow: var(--shadow);
  transform: translateY(-160%);
}

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

:focus-visible {
  outline: 3px solid color-mix(in srgb, var(--signal-bright) 65%, transparent);
  outline-offset: 3px;
}

.site-frame {
  min-height: 100vh;
  display: grid;
  grid-template: 72px minmax(0, 1fr) / 286px minmax(0, 1fr);
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 30;
  grid-column: 1 / -1;
  display: flex;
  align-items: center;
  height: 72px;
  padding: 0 24px;
  border-bottom: 1px solid var(--rule);
  background: color-mix(in srgb, var(--paper) 92%, transparent);
  backdrop-filter: blur(18px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-width: 262px;
  text-decoration: none;
}

.brand img { width: 83px; height: auto; }
.brand > span { width: 1px; height: 27px; background: var(--rule); }
.brand strong { font-size: 14px; font-weight: 600; letter-spacing: -0.01em; }
.brand em {
  margin-left: 4px;
  padding: 3px 6px;
  border-radius: 4px;
  background: var(--signal-pale);
  color: var(--signal);
  font-family: 'Centra Mono', monospace;
  font-size: 10px;
  font-style: normal;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.topbar-actions { display: flex; align-items: center; gap: 10px; margin-left: auto; }
.icon-button, .search-trigger, .hero-search {
  border: 1px solid var(--rule);
  background: var(--paper);
  cursor: pointer;
}

.icon-button {
  display: grid;
  width: 40px;
  height: 40px;
  place-items: center;
  border-radius: 50%;
}

.icon-button svg, .search-trigger svg, .hero-search svg, .search-input-wrap svg {
  width: 18px;
  fill: none;
  stroke: currentColor;
  stroke-linecap: round;
  stroke-width: 1.7;
}

.menu-button { display: none; margin-right: 10px; }
.theme-button .moon-icon { display: none; }
[data-theme='dark'] .theme-button .sun-icon { display: none; }
[data-theme='dark'] .theme-button .moon-icon { display: block; }
[data-theme='dark'] .brand img { filter: brightness(0) invert(1); }

.search-trigger {
  display: flex;
  align-items: center;
  gap: 9px;
  width: min(280px, 23vw);
  height: 40px;
  padding: 0 10px 0 13px;
  border-radius: 7px;
  color: var(--ink-soft);
  text-align: left;
}

.search-trigger span { flex: 1; }
kbd {
  padding: 3px 6px;
  border: 1px solid var(--rule);
  border-radius: 4px;
  background: var(--field);
  color: var(--ink-soft);
  font-family: 'Centra Mono', monospace;
  font-size: 10px;
}

.app-link {
  margin-left: 4px;
  color: var(--ledger-soft);
  font-size: 13px;
  font-weight: 600;
  text-decoration: none;
}
.app-link span { margin-left: 3px; }

.site-sidebar {
  position: sticky;
  top: 72px;
  height: calc(100vh - 72px);
  overflow-y: auto;
  padding: 38px 26px 28px;
  border-right: 1px solid var(--rule);
  background: var(--field);
}

.nav-section { margin-bottom: 30px; }
.nav-section h2 {
  margin: 0 0 9px 10px;
  color: var(--ink-soft);
  font-family: 'Centra Mono', monospace;
  font-size: 10px;
  font-weight: 400;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.nav-section a {
  position: relative;
  display: block;
  padding: 8px 10px;
  border-radius: 6px;
  color: var(--ink-soft);
  font-size: 14px;
  line-height: 1.3;
  text-decoration: none;
}

.nav-section a:hover { color: var(--ink); background: color-mix(in srgb, var(--signal-pale) 65%, transparent); }
.nav-section a[aria-current='page'] { color: var(--ledger-soft); background: var(--signal-pale); font-weight: 600; }
.nav-section a[aria-current='page']::before {
  content: '';
  position: absolute;
  top: 10px;
  bottom: 10px;
  left: -26px;
  width: 3px;
  background: var(--signal);
}

.sidebar-footer {
  margin-top: 42px;
  padding: 16px;
  border-top: 2px solid var(--signal);
  background: var(--paper);
  font-size: 12px;
}
.sidebar-footer span { display: block; color: var(--ink-soft); }
.sidebar-footer a { display: inline-block; margin-top: 6px; color: var(--ledger-soft); font-weight: 600; text-decoration: none; }
.sidebar-footer a span { display: inline; color: inherit; }
.sidebar-scrim { display: none; }

.main-content {
  position: relative;
  min-width: 0;
}

.article-page .main-content {
  display: grid;
  grid-template-columns: minmax(0, 780px) 210px;
  justify-content: center;
  gap: clamp(52px, 6vw, 92px);
  padding: 62px clamp(36px, 5vw, 80px) 90px;
}

.article-header { margin-bottom: 46px; }
.eyebrow {
  margin: 0 0 15px;
  color: var(--signal);
  font-family: 'Centra Mono', monospace;
  font-size: 11px;
  letter-spacing: 0.11em;
  text-transform: uppercase;
}

.article-header h1 {
  max-width: 720px;
  margin: 0;
  color: var(--ledger);
  font-family: 'GT Canon', Georgia, serif;
  font-size: clamp(42px, 5vw, 64px);
  font-weight: 400;
  letter-spacing: -0.045em;
  line-height: 0.98;
}

.article-summary {
  max-width: 680px;
  margin: 24px 0 0;
  color: var(--ink-soft);
  font-size: 18px;
  line-height: 1.6;
}

.article-rule { height: 2px; margin-top: 32px; background: var(--rule); }
.article-rule span { display: block; width: 112px; height: 2px; background: var(--signal); }

.prose { max-width: 760px; font-size: 16px; line-height: 1.72; }
.prose h2, .prose h3 { scroll-margin-top: 100px; color: var(--ledger); }
.prose h2 { margin: 60px 0 18px; font-family: 'GT Canon', Georgia, serif; font-size: 31px; font-weight: 400; letter-spacing: -0.025em; }
.prose h3 { margin: 38px 0 12px; font-size: 18px; font-weight: 600; }
.heading-anchor { text-decoration: none; }
.heading-anchor span { margin-left: 8px; color: transparent; font-family: 'Centra Mono', monospace; font-size: 0.7em; }
.heading-anchor:hover span { color: var(--signal-bright); }
.prose p { margin: 0 0 20px; }
.prose ul, .prose ol { margin: 0 0 24px; padding-left: 25px; }
.prose li { margin: 7px 0; padding-left: 4px; }
.prose li::marker { color: var(--signal); }
.prose a { color: var(--signal); text-decoration-color: color-mix(in srgb, var(--signal) 35%, transparent); text-underline-offset: 3px; }
.prose strong { color: var(--ink); font-weight: 600; }
.prose blockquote {
  margin: 30px 0;
  padding: 18px 22px;
  border-left: 3px solid var(--gold);
  background: color-mix(in srgb, var(--gold) 9%, var(--paper));
  color: var(--ink-soft);
}
.prose blockquote p:last-child { margin-bottom: 0; }
.prose code { padding: 2px 5px; border-radius: 4px; background: var(--code); font-family: 'Centra Mono', monospace; font-size: 0.88em; }
.prose pre { overflow-x: auto; padding: 20px; border-radius: 7px; background: var(--ledger); color: #edf6ff; }
.prose pre code { padding: 0; background: none; color: inherit; }
.prose table { width: 100%; margin: 30px 0; border-collapse: collapse; font-size: 14px; }
.prose th { padding: 12px 14px; border-bottom: 2px solid var(--ledger); color: var(--ledger); text-align: left; }
.prose td { padding: 13px 14px; border-bottom: 1px solid var(--rule); vertical-align: top; }
.prose tbody tr:hover { background: var(--field); }

.page-outline { position: sticky; top: 114px; align-self: start; max-height: calc(100vh - 150px); padding-left: 18px; }
.page-outline > p { margin: 0 0 13px; color: var(--ink); font-size: 12px; font-weight: 600; }
.page-outline nav { display: grid; gap: 10px; }
.page-outline a { color: var(--ink-soft); font-size: 12px; line-height: 1.35; text-decoration: none; }
.page-outline a:hover, .page-outline a[aria-current] { color: var(--signal); }
.outline-level-3 { padding-left: 10px; }
.outline-track { position: absolute; top: 1px; bottom: 0; left: 0; width: 1px; background: var(--rule); }
.outline-track span { display: block; width: 2px; height: 0; background: var(--signal); transition: height 240ms ease; }

.article-navigation { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; margin-top: 80px; padding-top: 26px; border-top: 1px solid var(--rule); }
.article-navigation a { display: grid; gap: 5px; color: var(--ledger-soft); text-decoration: none; }
.article-navigation .next { text-align: right; }
.article-navigation small { color: var(--ink-soft); font-family: 'Centra Mono', monospace; font-size: 10px; letter-spacing: 0.08em; text-transform: uppercase; }

.home-page .main-content { overflow: hidden; }
.home-hero {
  position: relative;
  display: grid;
  min-height: 540px;
  grid-template-columns: minmax(420px, 0.9fr) minmax(430px, 1.1fr);
  align-items: center;
  padding: 74px clamp(44px, 7vw, 116px);
  border-bottom: 1px solid var(--rule);
  background: var(--field);
}

.hero-copy { position: relative; z-index: 2; max-width: 680px; }
.hero-copy h1 {
  margin: 0;
  color: var(--ledger);
  font-family: 'GT Canon', Georgia, serif;
  font-size: clamp(52px, 6vw, 84px);
  font-weight: 400;
  letter-spacing: -0.055em;
  line-height: 0.94;
}
.hero-copy h1 span { color: var(--signal); }
.hero-copy > p:not(.eyebrow) { max-width: 610px; margin: 26px 0; color: var(--ink-soft); font-size: 18px; line-height: 1.55; }
.hero-search {
  display: flex;
  align-items: center;
  gap: 12px;
  width: min(100%, 500px);
  height: 56px;
  padding: 0 13px 0 18px;
  border-radius: 8px;
  box-shadow: 0 10px 30px rgba(10, 42, 76, 0.08);
  color: var(--ink-soft);
  text-align: left;
}
.hero-search span { flex: 1; }

.signal-field { position: relative; min-height: 360px; margin-left: -60px; opacity: 0.9; }
.signal-field svg { position: absolute; inset: 0; width: 100%; height: 100%; overflow: visible; }
.signal-grid path { fill: none; stroke: var(--rule); stroke-width: 1; }
.signal-area { fill: url('#none'); fill: color-mix(in srgb, var(--signal) 7%, transparent); stroke: none; }
.signal-line, .signal-projection { fill: none; stroke-linecap: round; stroke-width: 3; }
.signal-line { stroke: var(--signal); }
.signal-projection { stroke: var(--gold); stroke-dasharray: 7 9; }
.signal-field circle { fill: var(--paper); stroke: var(--signal); stroke-width: 3; }
.signal-label { position: absolute; z-index: 2; padding: 6px 9px; border: 1px solid var(--rule); border-radius: 4px; background: var(--paper); font-family: 'Centra Mono', monospace; font-size: 10px; }
.label-a { right: 42%; bottom: 42%; color: var(--signal); }
.label-b { top: 16%; right: 8%; color: var(--gold); }

.home-section { max-width: 1320px; margin: 0 auto; padding: 92px clamp(38px, 6vw, 88px); }
.section-heading { display: grid; grid-template-columns: minmax(150px, 0.4fr) 1fr; align-items: end; margin-bottom: 36px; }
.section-heading .eyebrow { margin: 0 0 5px; }
.section-heading h2 { margin: 0; color: var(--ledger); font-family: 'GT Canon', Georgia, serif; font-size: clamp(34px, 4vw, 48px); font-weight: 400; letter-spacing: -0.035em; }
.guide-grid { display: grid; grid-template-columns: repeat(2, 1fr); border-top: 1px solid var(--rule); }
.guide-card { position: relative; display: grid; min-height: 184px; grid-template-columns: 36px 1fr 24px; gap: 20px; padding: 30px 24px 30px 0; border-bottom: 1px solid var(--rule); text-decoration: none; }
.guide-card:nth-child(odd) { padding-right: 40px; border-right: 1px solid var(--rule); }
.guide-card:nth-child(even) { padding-left: 40px; }
.guide-card:hover h3, .guide-card:hover .card-arrow { color: var(--signal); }
.card-index { padding-top: 4px; color: var(--signal); font-family: 'Centra Mono', monospace; font-size: 10px; }
.guide-card h3 { margin: 0 0 10px; color: var(--ledger); font-size: 20px; transition: color 160ms ease; }
.guide-card p { margin: 0; color: var(--ink-soft); font-size: 14px; line-height: 1.55; }
.card-arrow { color: var(--ink-soft); transition: color 160ms ease, transform 160ms ease; }
.guide-card:hover .card-arrow { transform: translate(2px, -2px); }

.path-section { padding-top: 34px; }
.path-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
.path-card { padding: 24px; border: 1px solid var(--rule); border-top: 3px solid var(--signal); background: var(--field); }
.path-card h3 { margin: 0 0 20px; color: var(--ledger); font-size: 15px; }
.path-card ul { display: grid; gap: 11px; margin: 0; padding: 0; list-style: none; }
.path-card a { display: flex; justify-content: space-between; gap: 10px; color: var(--ink-soft); font-size: 13px; text-decoration: none; }
.path-card a:hover { color: var(--signal); }

.home-footer { display: flex; align-items: center; justify-content: space-between; margin-top: 20px; padding: 36px clamp(44px, 7vw, 116px); border-top: 1px solid var(--rule); background: var(--ledger); color: var(--paper); }
[data-theme='dark'] .home-footer { color: #0a2a4c; }
.home-footer div { display: flex; align-items: baseline; gap: 15px; }
.home-footer span { opacity: 0.7; font-size: 13px; }
.home-footer a { font-size: 13px; text-decoration: none; }

.search-dialog[hidden] { display: none; }
.search-dialog { position: fixed; inset: 0; z-index: 80; display: grid; place-items: start center; padding-top: min(14vh, 130px); }
.search-backdrop { position: absolute; inset: 0; border: 0; background: rgba(5, 18, 30, 0.66); backdrop-filter: blur(7px); cursor: default; }
.search-panel { position: relative; width: min(680px, calc(100vw - 32px)); max-height: min(680px, 72vh); overflow: hidden; border: 1px solid var(--rule); border-radius: 10px; background: var(--paper); box-shadow: var(--shadow); }
.search-input-wrap { display: flex; align-items: center; gap: 13px; height: 66px; padding: 0 17px; border-bottom: 1px solid var(--rule); }
.search-input-wrap svg { width: 21px; color: var(--signal); }
.search-input-wrap input { flex: 1; min-width: 0; border: 0; outline: 0; background: transparent; color: var(--ink); font-size: 17px; }
.search-input-wrap input::placeholder { color: var(--ink-soft); }
.search-results { max-height: calc(min(680px, 72vh) - 66px); overflow-y: auto; padding: 10px; }
.search-results a { display: grid; gap: 3px; padding: 13px 14px; border-radius: 7px; text-decoration: none; }
.search-results a:hover, .search-results a:focus-visible { background: var(--signal-pale); }
.search-results small { color: var(--signal); font-family: 'Centra Mono', monospace; font-size: 9px; letter-spacing: 0.08em; text-transform: uppercase; }
.search-results strong { color: var(--ledger); font-size: 15px; }
.search-results span, .search-hint { color: var(--ink-soft); font-size: 13px; }
.search-hint { margin: 0; padding: 26px 20px; text-align: center; }
.search-open { overflow: hidden; }

@media (max-width: 1160px) {
  .article-page .main-content { grid-template-columns: minmax(0, 760px); }
  .page-outline { display: none; }
  .home-hero { grid-template-columns: minmax(400px, 1fr) 0.8fr; }
  .signal-field { margin-left: -100px; opacity: 0.65; }
  .path-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 900px) {
  .site-frame { grid-template: 64px minmax(0, 1fr) / minmax(0, 1fr); }
  .topbar { height: 64px; padding: 0 16px; }
  .menu-button { display: grid; }
  .brand { min-width: 0; }
  .brand img { width: 68px; }
  .brand strong { display: none; }
  .search-trigger { width: 40px; border-radius: 50%; justify-content: center; }
  .search-trigger span, .search-trigger kbd, .app-link { display: none; }
  .site-sidebar { position: fixed; z-index: 50; top: 64px; bottom: 0; left: 0; width: min(310px, 84vw); height: auto; transform: translateX(-102%); transition: transform 220ms ease; }
  .menu-open .site-sidebar { transform: translateX(0); }
  .sidebar-scrim { position: fixed; z-index: 45; inset: 64px 0 0; border: 0; background: rgba(5, 18, 30, 0.58); }
  .menu-open .sidebar-scrim { display: block; }
  .article-page .main-content { padding: 46px clamp(22px, 6vw, 56px) 76px; }
  .home-hero { min-height: auto; grid-template-columns: 1fr; padding: 64px clamp(26px, 7vw, 58px) 74px; }
  .signal-field { position: absolute; inset: auto -12% 0 38%; min-height: 380px; margin: 0; opacity: 0.18; }
  .home-section { padding: 72px clamp(26px, 7vw, 58px); }
  .section-heading { grid-template-columns: 1fr; gap: 7px; }
}

@media (max-width: 620px) {
  .topbar-actions { gap: 7px; }
  .brand > span { display: none; }
  .hero-copy h1 { font-size: clamp(43px, 13vw, 58px); }
  .hero-copy > p:not(.eyebrow) { font-size: 16px; }
  .guide-grid { grid-template-columns: 1fr; }
  .guide-card, .guide-card:nth-child(odd), .guide-card:nth-child(even) { min-height: 0; padding: 25px 0; border-right: 0; }
  .path-grid { grid-template-columns: 1fr; }
  .home-footer { align-items: flex-start; flex-direction: column; gap: 22px; padding: 30px 26px; }
  .home-footer div { align-items: flex-start; flex-direction: column; gap: 4px; }
  .article-header h1 { font-size: 43px; }
  .article-summary { font-size: 16px; }
  .prose { font-size: 15px; }
  .prose h2 { font-size: 27px; }
  .prose table { display: block; overflow-x: auto; }
  .article-navigation { grid-template-columns: 1fr; }
  .article-navigation .next { text-align: left; }
}

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