:root {
  --bg-canvas: #F7F9FB;
  --bg-surface: #EBF1F6;
  --bg-paper: #FFFFFF;
  --ink: #0F1E2E;
  --ink-muted: #43576C;
  --accent: #1D4ED8;
  --accent-soft: #E8EFFD;
  --accent-amber: #C26D1F;
  --amber-soft: #FDF3E7;
  --safe: #0F766E;
  --safe-soft: #E6F4F1;
  --danger: #B91C1C;
  --danger-soft: #FDECEC;
  --rule: #CFDCE8;
  --rule-strong: #0F1E2E;

  --font-display: 'Vollkorn', Georgia, serif;
  --font-sans: 'Urbanist', system-ui, sans-serif;
  --font-mono: 'Inconsolata', monospace;

  --editorial-width: 76rem;
  --content-width: 49rem;
  --rail-width: 18.5rem;
  --container-pad: 1.25rem;
}

@media (min-width: 768px) {
  :root {
    --container-pad: 2.25rem;
  }
}

@media (min-width: 1280px) {
  :root {
    --container-pad: 3rem;
  }
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background-color: var(--bg-canvas);
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: 1.03125rem;
  line-height: 1.68;
  -webkit-font-smoothing: antialiased;
}

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

a {
  color: var(--accent);
  text-decoration-thickness: 1.5px;
  text-underline-offset: 3px;
}

a:hover {
  color: var(--ink);
}

:focus-visible {
  outline: 2.5px solid var(--accent);
  outline-offset: 2px;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--ink);
  color: var(--bg-paper);
  padding: 0.65rem 1rem;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  z-index: 200;
}

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

.acp-wrap {
  width: 100%;
  max-width: var(--editorial-width);
  margin-inline: auto;
  padding-inline: var(--container-pad);
}

/* Top Atmospheric Telemetry Bar (strictly inside header, never footer) */
.acp-header {
  background: var(--bg-paper);
  border-bottom: 2px solid var(--rule-strong);
}

.acp-telemetry-bar {
  background: var(--ink);
  color: #E2ECF5;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.02em;
  border-bottom: 1px solid #22384F;
}

.acp-telemetry-inner {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.5rem;
  align-items: center;
  justify-content: space-between;
  padding-block: 0.45rem;
}

.acp-tele-item {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  font-variant-numeric: tabular-nums;
}

.acp-tele-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: #38BDF8;
  flex-shrink: 0;
}

.acp-tele-amber {
  color: #FBBF77;
}

.acp-masthead-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding-block: 1rem;
}

.acp-brand {
  text-decoration: none;
  color: var(--ink);
  display: flex;
  flex-direction: column;
  gap: 0.12rem;
}

.acp-brand-name {
  font-family: var(--font-display);
  font-size: 1.4rem;
  font-weight: 700;
  letter-spacing: -0.025em;
  line-height: 1.15;
}

.acp-brand-name span {
  color: var(--accent);
}

.acp-brand-sub {
  font-family: var(--font-mono);
  font-size: 0.76rem;
  color: var(--ink-muted);
}

.acp-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem 0.9rem;
  align-items: center;
}

.acp-nav-link {
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--ink-muted);
  text-decoration: none;
  padding: 0.35rem 0.25rem;
  border-bottom: 2px solid transparent;
  transition: color 150ms ease, border-color 150ms ease;
}

.acp-nav-link:hover,
.acp-nav-link[aria-current="page"] {
  color: var(--ink);
  border-bottom-color: var(--accent);
}

/* Main Content & Typography */
.acp-main {
  padding-block: 2rem 3.5rem;
}

.acp-kicker {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--accent);
  margin: 0 0 0.5rem;
}

h1, h2, h3 {
  font-family: var(--font-display);
  color: var(--ink);
  letter-spacing: -0.024em;
  line-height: 1.18;
  text-wrap: balance;
}

h1 {
  font-size: clamp(1.95rem, 3.6vw, 2.85rem);
  font-weight: 700;
  margin: 0 0 0.9rem;
}

h2 {
  font-size: clamp(1.42rem, 2.4vw, 1.85rem);
  font-weight: 600;
  margin: 2.2rem 0 0.75rem;
  padding-top: 1.1rem;
  border-top: 1px solid var(--rule);
}

h3 {
  font-size: 1.2rem;
  font-weight: 600;
  margin: 1.5rem 0 0.45rem;
}

p {
  margin: 0 0 1rem;
  max-width: 66ch;
}

ul, ol {
  margin: 0 0 1.1rem;
  padding-left: 1.3rem;
  max-width: 66ch;
}

li {
  margin-bottom: 0.42rem;
}

/* 68/32 Manuscript Lookup Masthead */
.acp-hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.9fr) minmax(0, 1fr);
  gap: 2.25rem;
  align-items: start;
  padding-bottom: 2rem;
  border-bottom: 2px solid var(--rule-strong);
}

@media (max-width: 960px) {
  .acp-hero-grid {
    grid-template-columns: minmax(0, 1fr);
    gap: 1.5rem;
  }
}

.acp-lead-dek {
  font-size: 1.12rem;
  color: var(--ink-muted);
  line-height: 1.6;
  margin-bottom: 1.15rem;
}

/* Link-free GEO Answer Capsule */
.answer-capsule {
  background: var(--bg-surface);
  border-left: 4px solid var(--accent);
  padding: 1rem 1.25rem;
  margin: 1.15rem 0 1.4rem;
}

.answer-label {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--accent);
  margin-bottom: 0.35rem;
}

.answer-box {
  font-size: 0.99rem;
  line-height: 1.62;
  color: var(--ink);
  font-weight: 500;
}

/* Inline Legacy Citation Lookup Bar */
.acp-lookup-bar {
  background: var(--bg-paper);
  border: 1px solid var(--rule);
  border-top: 2px solid var(--accent-amber);
  padding: 1rem 1.15rem;
  margin-top: 1.2rem;
}

.acp-lookup-title {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--accent-amber);
  margin: 0 0 0.6rem;
}

.acp-lookup-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  margin-bottom: 0.85rem;
}

.acp-lookup-readout {
  background: var(--bg-canvas);
  border: 1px solid var(--rule);
  padding: 0.8rem 0.95rem;
  font-size: 0.92rem;
}

.acp-doi-code {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  background: var(--bg-surface);
  color: var(--ink);
  padding: 0.12rem 0.4rem;
  border: 1px solid var(--rule);
}

/* Documentary Plate (32% column or inner route lead) */
.acp-hero-plate {
  background: var(--bg-paper);
  border: 1px solid var(--rule);
  padding: 0.75rem;
}

.acp-hero-plate img {
  width: 100%;
  aspect-ratio: 3 / 2;
  object-fit: cover;
}

.acp-figcap {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  line-height: 1.48;
  color: var(--ink-muted);
  margin-top: 0.6rem;
}

.acp-figure {
  margin: 1.5rem 0;
  background: var(--bg-paper);
  border: 1px solid var(--rule);
  padding: 0.85rem;
}

/* Interactive Photochemical & AOD Workbench */
.acp-workbench {
  background: var(--bg-paper);
  border: 1px solid var(--rule);
  border-top: 3px solid var(--accent);
  padding: 1.4rem;
  margin: 2rem 0;
}

.acp-wb-head {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.9rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--rule);
  margin-bottom: 1.2rem;
}

.acp-wb-head h2,
.acp-wb-head h3 {
  margin: 0;
  padding: 0;
  border: 0;
}

.acp-wb-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
}

.acp-wb-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr);
  gap: 1.6rem;
  align-items: start;
}

@media (max-width: 900px) {
  .acp-wb-grid {
    grid-template-columns: minmax(0, 1fr);
  }
}

.acp-ctrl-group {
  margin-bottom: 1.05rem;
}

.acp-ctrl-label {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--ink);
  margin-bottom: 0.4rem;
}

.acp-pill-group {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
}

.acp-pill {
  appearance: none;
  background: var(--bg-canvas);
  color: var(--ink);
  border: 1px solid var(--rule);
  padding: 0.55rem 0.85rem;
  min-height: 44px;
  font-family: var(--font-sans);
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: background-color 150ms ease, border-color 150ms ease, color 150ms ease;
}

.acp-pill:hover {
  border-color: var(--accent);
}

.acp-pill.is-active {
  background: var(--accent);
  color: var(--bg-paper);
  border-color: var(--accent);
}

.acp-stepper {
  display: inline-flex;
  align-items: center;
  border: 1px solid var(--rule);
  background: var(--bg-canvas);
}

.acp-stepper-btn {
  appearance: none;
  background: var(--bg-surface);
  color: var(--ink);
  border: 0;
  width: 44px;
  height: 44px;
  font-family: var(--font-mono);
  font-size: 1.1rem;
  font-weight: 600;
  cursor: pointer;
  transition: background-color 150ms ease;
}

.acp-stepper-btn:hover {
  background: var(--accent-soft);
}

.acp-stepper-val {
  min-width: 6.5rem;
  text-align: center;
  font-family: var(--font-mono);
  font-size: 0.95rem;
  font-weight: 600;
  font-variant-numeric: tabular-nums;
  padding-inline: 0.6rem;
}

.acp-readout-panel {
  background: var(--bg-canvas);
  border: 1px solid var(--rule);
  padding: 1.15rem;
}

.acp-regime-banner {
  padding: 0.85rem 1rem;
  border-left: 4px solid var(--accent);
  background: var(--accent-soft);
  margin-bottom: 1rem;
}

.acp-regime-banner.is-amber {
  border-left-color: var(--accent-amber);
  background: var(--amber-soft);
}

.acp-regime-banner.is-safe {
  border-left-color: var(--safe);
  background: var(--safe-soft);
}

.acp-regime-banner.is-danger {
  border-left-color: var(--danger);
  background: var(--danger-soft);
}

.acp-regime-title {
  font-family: var(--font-mono);
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--ink);
  margin-bottom: 0.2rem;
}

.acp-metric-row {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.75rem;
  margin-bottom: 0.9rem;
}

@media (max-width: 520px) {
  .acp-metric-row {
    grid-template-columns: minmax(0, 1fr);
  }
}

.acp-metric-cell {
  background: var(--bg-paper);
  border: 1px solid var(--rule);
  padding: 0.65rem 0.8rem;
}

.acp-metric-k {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  color: var(--ink-muted);
  display: block;
}

.acp-metric-v {
  font-family: var(--font-mono);
  font-size: 1.18rem;
  font-weight: 600;
  font-variant-numeric: tabular-nums;
  color: var(--ink);
}

.acp-wb-note {
  font-size: 0.88rem;
  color: var(--ink-muted);
  margin: 0;
}

/* Booktabs Empirical Tables with strict :not(td):not(th) defense */
.table-responsive-wrap {
  width: 100%;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  margin: 1.35rem 0;
}

.acp-table {
  width: 100%;
  border-collapse: collapse;
  border-top: 2px solid var(--rule-strong);
  border-bottom: 2px solid var(--rule-strong);
  font-size: 0.9rem;
  line-height: 1.48;
  font-variant-numeric: tabular-nums;
  background: var(--bg-paper);
}

.acp-table thead th {
  text-align: left;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  font-weight: 600;
  color: var(--ink);
  background: var(--bg-surface);
  border-bottom: 1.5px solid var(--rule-strong);
  padding: 0.65rem 0.85rem;
}

.acp-table tbody td {
  padding: 0.7rem 0.85rem;
  border-bottom: 1px solid var(--rule);
  vertical-align: top;
  color: var(--ink);
}

.acp-table tbody tr:last-child td {
  border-bottom: 0;
}

:is(.acp-badge, .acp-badge-amber, .acp-badge-safe):not(td):not(th) {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  font-weight: 600;
  padding: 0.14rem 0.45rem;
  background: var(--accent-soft);
  color: var(--accent);
  white-space: nowrap;
}

:is(.acp-badge-amber):not(td):not(th) {
  background: var(--amber-soft);
  color: #8A450A;
}

:is(.acp-badge-safe):not(td):not(th) {
  background: var(--safe-soft);
  color: var(--safe);
}

/* Inline Spectral & Mechanism SVGs */
.acp-diagram {
  width: 100%;
  height: auto;
  display: block;
  background: var(--bg-canvas);
  border: 1px solid var(--rule);
}

/* Two-Column Editorial Grid for Pillar Pages */
.acp-spec-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) var(--rail-width);
  gap: 3rem;
  align-items: start;
}

@media (max-width: 1024px) {
  .acp-spec-grid {
    grid-template-columns: minmax(0, 1fr);
    gap: 1.75rem;
  }
}

.acp-prose {
  min-width: 0;
  max-width: var(--content-width);
}

.acp-rail {
  position: sticky;
  top: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1.1rem;
}

@media (max-width: 1024px) {
  .acp-rail {
    position: static;
  }
}

.acp-toc-card,
.acp-rail-card {
  background: var(--bg-paper);
  border: 1px solid var(--rule);
  border-top: 2px solid var(--rule-strong);
  padding: 1rem;
}

.acp-rail-title {
  font-family: var(--font-mono);
  font-size: 0.76rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--ink-muted);
  margin: 0 0 0.65rem;
}

.acp-toc-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.acp-toc-list li {
  margin-bottom: 0.45rem;
  font-size: 0.9rem;
}

.acp-toc-list a {
  text-decoration: none;
  color: var(--ink-muted);
}

.acp-toc-list a:hover {
  color: var(--accent);
}

/* Topical Hub Index Grid on Home */
.acp-hub-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.25rem;
  margin: 1.25rem 0 2rem;
}

@media (max-width: 760px) {
  .acp-hub-grid {
    grid-template-columns: minmax(0, 1fr);
  }
}

.acp-hub-item {
  background: var(--bg-paper);
  border: 1px solid var(--rule);
  border-left: 3px solid var(--accent);
  padding: 1.05rem 1.15rem;
}

.acp-hub-item h3 {
  margin: 0 0 0.35rem;
  font-size: 1.12rem;
}

.acp-hub-item p {
  margin: 0 0 0.55rem;
  font-size: 0.94rem;
  color: var(--ink-muted);
}

/* Archival Citation Disclosures (#archive-*) */
.acp-archive-section {
  margin-top: 2.25rem;
  padding-top: 1.25rem;
  border-top: 2px solid var(--rule-strong);
}

.ref-disclosure {
  background: var(--bg-paper);
  border: 1px solid var(--rule);
  border-left: 3px solid var(--accent-amber);
  padding: 0.85rem 1.05rem;
  margin-bottom: 0.85rem;
}

.ref-disclosure summary {
  cursor: pointer;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1.02rem;
  color: var(--ink);
}

.acp-archive-meta {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--ink-muted);
  margin: 0.55rem 0 0.5rem;
}

/* Pure Human-Readable 3-Column Footer (Zero telemetry tags, zero NPI pills) */
.acp-footer {
  background: var(--bg-surface);
  border-top: 2px solid var(--rule-strong);
  padding-block: 2.25rem 1.75rem;
  font-size: 0.92rem;
  color: var(--ink-muted);
}

.acp-footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr;
  gap: 2rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--rule);
}

@media (max-width: 820px) {
  .acp-footer-grid {
    grid-template-columns: minmax(0, 1fr);
    gap: 1.35rem;
  }
}

.acp-footer-title {
  font-family: var(--font-display);
  font-size: 1.02rem;
  font-weight: 700;
  color: var(--ink);
  margin: 0 0 0.55rem;
}

.acp-footer ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.acp-footer li {
  margin-bottom: 0.35rem;
}

.acp-footer-bottom {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 0.75rem;
  padding-top: 1.1rem;
  font-size: 0.84rem;
}

.is-hidden {
  display: none;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  .acp-nav-link,
  .acp-pill,
  .acp-stepper-btn {
    transition: none;
  }
}

@media print {
  .acp-telemetry-bar,
  .acp-nav,
  .acp-rail,
  .acp-footer {
    display: none;
  }
  body {
    background: #FFFFFF;
    color: #000000;
  }
  .acp-workbench,
  .acp-table {
    break-inside: avoid;
  }
}