/* ==========================================================================
   LITHOS — INTERNATIONAL TYPOGRAPHIC STYLE / SWISS PETROLOGICAL ARCHIVE
   Plain CSS3 | Exposed Grid System | Light & Dark Themes | Fully Responsive
   ========================================================================== */

:root,
html[data-theme="light"] {
  --bg-canvas: #F3F1EB;
  --bg-surface: #FAF9F5;
  --bg-elevated: #ECE9E0;
  --bg-interactive: #E5E1D6;
  --text-primary: #111110;
  --text-secondary: #484641;
  --text-muted: #6E6B64;
  --border-strong: #111110;
  --border-grid: #CBC7BC;
  --border-subtle: #DCD8CE;
  --accent: #D92B1E;
  --accent-soft: rgba(217, 43, 30, 0.1);
  --accent-contrast: #FFFFFF;
  --status-pass: #1C6B3A;
  --status-neutral: #8A5A00;
  --header-bg: rgba(243, 241, 235, 0.92);
  --shadow-swiss: 4px 4px 0px #111110;

  --font-display: 'Space Grotesk', 'Plus Jakarta Sans', 'Helvetica Neue', Arial, sans-serif;
  --font-sans: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'IBM Plex Mono', 'JetBrains Mono', Consolas, monospace;

  --max-width: 1440px;
  --header-height: 60px;
  --ease-out-expo: cubic-bezier(0.16, 1, 0.3, 1);
  color-scheme: light;
}

html[data-theme="dark"] {
  --bg-canvas: #0C0E11;
  --bg-surface: #13161B;
  --bg-elevated: #1A1E25;
  --bg-interactive: #232831;
  --text-primary: #F2EFE9;
  --text-secondary: #B4B0A8;
  --text-muted: #7E7B74;
  --border-strong: #F2EFE9;
  --border-grid: #2A2F37;
  --border-subtle: #1F232A;
  --accent: #FF4433;
  --accent-soft: rgba(255, 68, 51, 0.14);
  --accent-contrast: #0C0E11;
  --status-pass: #3DD675;
  --status-neutral: #F5B841;
  --header-bg: rgba(12, 14, 17, 0.92);
  --shadow-swiss: 4px 4px 0px #FF4433;
  color-scheme: dark;
}

/* Reset & Base */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-height) + 16px);
  font-size: 16px;
}

body {
  background-color: var(--bg-canvas);
  color: var(--text-primary);
  font-family: var(--font-sans);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
  transition: background-color 0.25s var(--ease-out-expo), color 0.25s var(--ease-out-expo);
}

/* Subtle fixed archival grain overlay */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 40;
  opacity: 0.025;
  background-image: radial-gradient(var(--text-primary) 0.75px, transparent 0.75px);
  background-size: 12px 12px;
}

/* Skip to content accessibility link */
.skip-link {
  position: fixed;
  top: -100px;
  left: 16px;
  z-index: 1000;
  background: var(--accent);
  color: #FFFFFF;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 10px 16px;
  text-decoration: none;
  border: 2px solid var(--border-strong);
}

.skip-link:focus {
  top: 12px;
}

/* Accessible Focus States */
:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* Typography Utilities */
.mono-label {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 500;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  color: var(--text-muted);
  display: block;
}

.mono-value {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--text-primary);
}

.mono-tag,
.mono-coord {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.mono-badge {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 3px 8px;
  border: 1px solid var(--border-grid);
  background: var(--bg-elevated);
  color: var(--text-primary);
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.mono-badge.accent-badge {
  border-color: var(--accent);
  background: var(--accent-soft);
  color: var(--accent);
}

/* ==========================================================================
   HEADER & NAVIGATION
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: var(--header-bg);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border-strong);
}

.header-grid {
  max-width: var(--max-width);
  margin: 0 auto;
  min-height: var(--header-height);
  display: grid;
  grid-template-columns: auto 1fr auto auto;
  border-left: 1px solid var(--border-grid);
  border-right: 1px solid var(--border-grid);
}

.header-cell {
  display: flex;
  align-items: center;
  padding: 0 20px;
  border-right: 1px solid var(--border-grid);
}

.header-cell:last-child {
  border-right: none;
}

.brand-link {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--text-primary);
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: var(--accent);
}

.brand-name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.05rem;
  letter-spacing: 0.1em;
}

.brand-sub {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--text-muted);
  padding-left: 10px;
  border-left: 1px solid var(--border-grid);
}

.meta-cell {
  flex-direction: column;
  justify-content: center;
  align-items: flex-start;
  gap: 2px;
}

.nav-list {
  display: flex;
  align-items: center;
  list-style: none;
  gap: 4px;
}

.nav-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 12px;
  text-decoration: none;
  color: var(--text-secondary);
  font-family: var(--font-mono);
  font-size: 0.74rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  transition: color 0.18s ease, background-color 0.18s ease;
}

.nav-link:hover {
  color: var(--text-primary);
  background-color: var(--bg-elevated);
}

.nav-num {
  color: var(--accent);
  font-weight: 600;
}

/* Theme Toggle Button */
.theme-control-group {
  display: flex;
  align-items: center;
  gap: 6px;
}

.theme-toggle-btn {
  appearance: none;
  background: var(--bg-surface);
  color: var(--text-primary);
  border: 1px solid var(--border-strong);
  padding: 7px 12px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
  transition: transform 0.15s ease, background-color 0.15s ease;
}

.theme-toggle-btn:hover {
  background: var(--bg-interactive);
}

.theme-toggle-btn:active {
  transform: translateY(1px);
}

.theme-indicator {
  width: 8px;
  height: 8px;
  background: var(--accent);
  display: inline-block;
}

html[data-theme="light"] .theme-icon-moon {
  display: none;
}

html[data-theme="dark"] .theme-icon-sun {
  display: none;
}

.theme-system-btn {
  appearance: none;
  background: transparent;
  color: var(--text-muted);
  border: 1px solid var(--border-grid);
  padding: 7px 8px;
  font-family: var(--font-mono);
  font-size: 0.65rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  cursor: pointer;
}

.theme-system-btn:hover {
  color: var(--text-primary);
  border-color: var(--border-strong);
}

/* ==========================================================================
   SWISS STRUCTURAL CONTAINERS & HERO
   ========================================================================== */
.swiss-grid {
  max-width: var(--max-width);
  margin: 0 auto;
  border-left: 1px solid var(--border-grid);
  border-right: 1px solid var(--border-grid);
}

.hero-section {
  border-bottom: 2px solid var(--border-strong);
}

.hero-grid {
  display: grid;
  grid-template-columns: 240px 1.15fr 1fr;
  border-bottom: 1px solid var(--border-grid);
}

.hero-index-col {
  padding: 32px 24px;
  border-right: 1px solid var(--border-grid);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  background: var(--bg-surface);
}

.index-stamp {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.index-stamp .mono-tag {
  color: var(--accent);
  font-weight: 600;
}

.hero-vertical-rule {
  width: 1px;
  flex: 1;
  min-height: 48px;
  background: var(--border-grid);
  margin: 24px 0;
}

.hero-telemetry {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.telemetry-row {
  border-top: 1px solid var(--border-subtle);
  padding-top: 8px;
}

.telemetry-row dt {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  letter-spacing: 0.08em;
  color: var(--text-muted);
}

.telemetry-row dd {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-top: 2px;
}

.hero-main-col {
  padding: 48px 44px;
  border-right: 1px solid var(--border-grid);
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.eyebrow-row {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 20px;
}

.swiss-cross {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 20px;
  height: 20px;
  background: var(--accent);
  color: #FFFFFF;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 0.85rem;
  line-height: 1;
}

.eyebrow-text {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-secondary);
}

.hero-display {
  font-family: var(--font-display);
  font-size: clamp(3.1rem, 6.2vw, 5.8rem);
  font-weight: 700;
  line-height: 0.92;
  letter-spacing: -0.04em;
  text-transform: uppercase;
  margin-bottom: 28px;
}

.accent-stroke {
  color: var(--accent);
}

.hero-lead {
  font-size: 1.06rem;
  line-height: 1.65;
  color: var(--text-secondary);
  max-width: 58ch;
  margin-bottom: 36px;
}

.hero-cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* Swiss Buttons */
.btn-swiss {
  appearance: none;
  display: inline-flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 13px 20px;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  text-decoration: none;
  border: 1px solid var(--border-strong);
  cursor: pointer;
  transition: transform 0.15s ease, background-color 0.18s ease, color 0.18s ease;
}

.btn-swiss:active {
  transform: translateY(1px);
}

.btn-primary {
  background: var(--text-primary);
  color: var(--bg-canvas);
}

.btn-primary:hover {
  background: var(--accent);
  border-color: var(--accent);
  color: #FFFFFF;
}

.btn-secondary {
  background: var(--bg-surface);
  color: var(--text-primary);
}

.btn-secondary:hover {
  background: var(--bg-interactive);
}

.btn-compact {
  padding: 9px 14px;
  font-size: 0.72rem;
  background: var(--bg-surface);
  color: var(--text-primary);
}

.btn-compact:hover {
  background: var(--bg-interactive);
}

.btn-accent-outline {
  border-color: var(--accent);
  color: var(--accent);
}

.btn-accent-outline:hover {
  background: var(--accent);
  color: #FFFFFF;
}

/* Hero Right Diagram Column */
.hero-visual-col {
  padding: 28px;
  background: var(--bg-surface);
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.diagram-frame {
  border: 1px solid var(--border-grid);
  background: var(--bg-canvas);
  display: flex;
  flex-direction: column;
}

.diagram-header {
  padding: 10px 14px;
  border-bottom: 1px solid var(--border-grid);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  flex-wrap: wrap;
}

.hero-svg-container {
  padding: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
}

#hero-strata-svg {
  width: 100%;
  max-width: 420px;
  height: auto;
  display: block;
}

.strata-zone {
  cursor: pointer;
  transition: opacity 0.2s ease;
}

.strata-zone:hover .strata-fill,
.strata-zone:focus .strata-fill {
  stroke: var(--accent);
  stroke-width: 2.5px;
}

.svg-label-box {
  fill: var(--bg-surface);
  stroke: var(--border-strong);
  stroke-width: 1;
}

.svg-label-accent {
  stroke: var(--accent);
}

.svg-mono-text {
  font-family: var(--font-mono);
  font-size: 9.5px;
  font-weight: 600;
  letter-spacing: 0.06em;
  fill: var(--text-primary);
}

.svg-mono-accent {
  fill: var(--accent);
}

.diagram-footer {
  padding: 10px 14px;
  border-top: 1px solid var(--border-grid);
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.06em;
}

.legend-item {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.legend-swatch {
  width: 10px;
  height: 10px;
  border: 1px solid var(--border-strong);
  display: inline-block;
}

.swatch-igneous {
  background: var(--accent);
}

.swatch-sedimentary {
  background: var(--text-secondary);
}

.swatch-metamorphic {
  background: repeating-linear-gradient(45deg, var(--text-primary), var(--text-primary) 2px, transparent 2px, transparent 4px);
}

/* Trilogy Overview Strip */
.trilogy-overview-strip {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
}

.trilogy-overview-card {
  appearance: none;
  background: var(--bg-canvas);
  color: var(--text-primary);
  text-align: left;
  padding: 24px 28px;
  border: none;
  border-right: 1px solid var(--border-grid);
  cursor: pointer;
  transition: background-color 0.18s ease;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.trilogy-overview-card:last-child {
  border-right: none;
}

.trilogy-overview-card:hover {
  background: var(--bg-surface);
}

.trilogy-overview-card.active {
  background: var(--bg-surface);
  box-shadow: inset 0 3px 0 var(--accent);
}

.trilogy-card-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
}

.mono-num {
  color: var(--accent);
  font-weight: 600;
}

.mono-pill {
  color: var(--text-muted);
}

.trilogy-card-title {
  font-family: var(--font-display);
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.trilogy-card-desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

.trilogy-card-examples {
  margin-top: 6px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-muted);
  letter-spacing: 0.04em;
}

/* ==========================================================================
   SECTION HEADERS & GENERAL BLOCKS
   ========================================================================== */
.section-block {
  border-bottom: 2px solid var(--border-strong);
}

.section-header-bar {
  max-width: var(--max-width);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 240px 1fr auto;
  border-left: 1px solid var(--border-grid);
  border-right: 1px solid var(--border-grid);
  border-bottom: 1px solid var(--border-strong);
  background: var(--bg-surface);
}

.section-num-col {
  padding: 28px 24px;
  border-right: 1px solid var(--border-grid);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.section-index {
  font-family: var(--font-display);
  font-size: 3rem;
  font-weight: 700;
  line-height: 0.9;
  color: var(--accent);
  letter-spacing: -0.04em;
}

.section-subindex {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  margin-top: 12px;
}

.section-title-col {
  padding: 28px 36px;
  border-right: 1px solid var(--border-grid);
}

.section-heading {
  font-family: var(--font-display);
  font-size: clamp(1.65rem, 2.8vw, 2.35rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  margin-bottom: 8px;
}

.section-subtitle {
  font-size: 0.96rem;
  color: var(--text-secondary);
  max-width: 72ch;
}

.section-controls-col {
  padding: 28px 24px;
  display: flex;
  align-items: center;
  justify-content: flex-end;
}

/* Filter Tabs */
.view-mode-switch {
  display: inline-flex;
  flex-wrap: wrap;
  border: 1px solid var(--border-strong);
  background: var(--bg-canvas);
}

.rock-filter-tab {
  appearance: none;
  background: transparent;
  color: var(--text-secondary);
  border: none;
  border-right: 1px solid var(--border-grid);
  padding: 10px 14px;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  cursor: pointer;
  transition: background-color 0.15s ease, color 0.15s ease;
}

.rock-filter-tab:last-child {
  border-right: none;
}

.rock-filter-tab:hover {
  color: var(--text-primary);
  background: var(--bg-elevated);
}

.rock-filter-tab.active {
  background: var(--text-primary);
  color: var(--bg-canvas);
}

/* ==========================================================================
   SECTION 01: ROCK CLASSES & SPECIMEN CARDS
   ========================================================================== */
.rock-classes-wrapper {
  max-width: var(--max-width);
  margin: 0 auto;
  border-left: 1px solid var(--border-grid);
  border-right: 1px solid var(--border-grid);
}

.rock-class-module {
  border-bottom: 1px solid var(--border-strong);
  display: grid;
  grid-template-columns: 380px 1fr;
}

.rock-class-module:last-child {
  border-bottom: none;
}

.rock-class-dossier {
  padding: 32px 28px;
  border-right: 1px solid var(--border-grid);
  background: var(--bg-surface);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 24px;
}

.dossier-header-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
}

.dossier-code {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent);
  letter-spacing: 0.08em;
}

.dossier-etymology {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--text-muted);
}

.dossier-title {
  font-family: var(--font-display);
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.05;
  margin-bottom: 14px;
}

.dossier-formation-label {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  font-weight: 600;
  letter-spacing: 0.09em;
  color: var(--accent);
  text-transform: uppercase;
  margin-bottom: 6px;
  display: block;
}

.dossier-formation-text {
  font-size: 0.92rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 16px;
}

.formation-steps-list {
  list-style: none;
  border-top: 1px solid var(--border-grid);
}

.formation-step-item {
  padding: 9px 0;
  border-bottom: 1px solid var(--border-subtle);
  display: grid;
  grid-template-columns: 28px 1fr;
  font-size: 0.84rem;
  color: var(--text-primary);
}

.step-idx {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--accent);
}

.dossier-subtypes {
  padding: 14px;
  background: var(--bg-canvas);
  border: 1px solid var(--border-grid);
}

.dossier-subtypes-Grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-top: 8px;
}

.subtype-item strong {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.74rem;
  color: var(--text-primary);
}

.subtype-item span {
  font-size: 0.78rem;
  color: var(--text-secondary);
}

/* Specimen Cards Grid (4 Examples per Rock Class) */
.rock-specimens-column {
  display: flex;
  flex-direction: column;
}

.specimens-col-header {
  padding: 12px 24px;
  border-bottom: 1px solid var(--border-grid);
  background: var(--bg-elevated);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

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

.specimen-card {
  padding: 24px;
  border-right: 1px solid var(--border-grid);
  border-bottom: 1px solid var(--border-grid);
  background: var(--bg-canvas);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 16px;
  cursor: pointer;
  text-align: left;
  transition: background-color 0.18s ease;
}

.specimen-card:nth-child(2n) {
  border-right: none;
}

.specimen-card:nth-last-child(-n+2) {
  border-bottom: none;
}

.specimen-card:hover {
  background: var(--bg-surface);
}

.specimen-card.selected-specimen {
  background: var(--bg-surface);
  box-shadow: inset 3px 0 0 var(--accent);
}

.specimen-card-top {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
}

.specimen-meta-head {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.specimen-id {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--text-muted);
  letter-spacing: 0.08em;
}

.specimen-name {
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--text-primary);
}

.specimen-subtype-tag {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.specimen-thumb-svg {
  width: 76px;
  height: 76px;
  flex-shrink: 0;
  border: 1px solid var(--border-strong);
  background: var(--bg-elevated);
  display: flex;
  align-items: center;
  justify-content: center;
}

.specimen-thumb-svg svg {
  width: 100%;
  height: 100%;
  display: block;
}

.specimen-desc {
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.55;
}

.specimen-specs-foot {
  padding-top: 12px;
  border-top: 1px solid var(--border-subtle);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--text-muted);
}

.inspect-cta {
  color: var(--text-primary);
  font-weight: 600;
}

.specimen-card.selected-specimen .inspect-cta {
  color: var(--accent);
}

/* Specimen Deep-Dive Inspector Bar */
.specimen-inspector {
  max-width: var(--max-width);
  margin: 0 auto;
  border-left: 1px solid var(--border-grid);
  border-right: 1px solid var(--border-grid);
  border-top: 2px solid var(--border-strong);
  background: var(--bg-surface);
}

.inspector-grid {
  display: grid;
  grid-template-columns: 340px 1fr;
}

.inspector-visual-cell {
  padding: 24px;
  border-right: 1px solid var(--border-grid);
  background: var(--bg-elevated);
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.inspector-svg-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 8px;
}

.inspector-svg-mount {
  width: 100%;
  aspect-ratio: 1 / 1;
  max-width: 260px;
  margin: 0 auto;
  border: 1px solid var(--border-strong);
  background: var(--bg-canvas);
  display: flex;
  align-items: center;
  justify-content: center;
}

.inspector-svg-mount svg {
  width: 100%;
  height: 100%;
}

.inspector-data-cell {
  padding: 28px 36px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.inspector-eyebrow {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  margin-bottom: 10px;
}

.inspector-title {
  font-family: var(--font-display);
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 10px;
}

.inspector-description {
  font-size: 0.96rem;
  color: var(--text-secondary);
  max-width: 75ch;
  margin-bottom: 22px;
}

.inspector-metrics-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  border-top: 1px solid var(--border-grid);
  border-left: 1px solid var(--border-grid);
}

.metric-box {
  padding: 12px 16px;
  border-right: 1px solid var(--border-grid);
  border-bottom: 1px solid var(--border-grid);
  background: var(--bg-canvas);
}

.metric-box dt {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  margin-bottom: 4px;
}

.metric-box dd {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-primary);
}

/* ==========================================================================
   SECTION 02: INTERACTIVE LITHOSPHERIC ROCK CYCLE
   ========================================================================== */
.cycle-grid {
  display: grid;
  grid-template-columns: 1.15fr 1fr;
}

.cycle-diagram-col {
  padding: 28px;
  border-right: 1px solid var(--border-grid);
  background: var(--bg-canvas);
  display: flex;
  align-items: center;
  justify-content: center;
}

#rock-cycle-svg {
  width: 100%;
  max-width: 640px;
  height: auto;
}

.cycle-pathway {
  cursor: pointer;
}

.cycle-pill {
  fill: var(--bg-surface);
  stroke: var(--border-grid);
  stroke-width: 1;
  transition: stroke 0.15s ease, fill 0.15s ease;
}

.cycle-pathway:hover .cycle-pill,
.cycle-pathway.active .cycle-pill {
  stroke: var(--accent);
  fill: var(--bg-elevated);
}

.cycle-pathway:hover .cycle-arc,
.cycle-pathway.active .cycle-arc {
  stroke: var(--accent);
  stroke-width: 3.2px;
}

.cycle-node {
  cursor: pointer;
}

.cycle-node-box {
  fill: var(--bg-surface);
  stroke: var(--border-strong);
  stroke-width: 2;
}

.cycle-node:hover .cycle-node-box {
  stroke: var(--accent);
}

.svg-node-title {
  font-family: var(--font-display);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.06em;
  fill: var(--text-primary);
}

.cycle-info-col {
  padding: 32px;
  background: var(--bg-surface);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 20px;
}

.cycle-pathway-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.pathway-btn {
  appearance: none;
  background: var(--bg-canvas);
  color: var(--text-secondary);
  border: 1px solid var(--border-grid);
  padding: 8px 12px;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  cursor: pointer;
  transition: all 0.15s ease;
}

.pathway-btn:hover {
  border-color: var(--border-strong);
  color: var(--text-primary);
}

.pathway-btn.active {
  background: var(--text-primary);
  color: var(--bg-canvas);
  border-color: var(--text-primary);
}

.cycle-readout-card {
  padding: 24px;
  border: 1px solid var(--border-strong);
  background: var(--bg-canvas);
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.cycle-readout-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}

.cycle-readout-title {
  font-family: var(--font-display);
  font-size: 1.45rem;
  font-weight: 700;
}

.cycle-readout-desc {
  font-size: 0.92rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.cycle-transformation-example {
  margin-top: 6px;
  padding-top: 12px;
  border-top: 1px solid var(--border-grid);
  display: flex;
  flex-direction: column;
  gap: 4px;
  font-size: 0.88rem;
}

/* ==========================================================================
   SECTION 03: INTERACTIVE MOHS HARDNESS SCALE
   ========================================================================== */
.scale-metric-toggle {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.metric-mode-btn {
  appearance: none;
  background: var(--bg-canvas);
  color: var(--text-secondary);
  border: 1px solid var(--border-strong);
  padding: 8px 12px;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  cursor: pointer;
}

.metric-mode-btn.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #FFFFFF;
}

.mohs-workspace {
  display: grid;
  grid-template-columns: 1.05fr 1fr;
}

.mohs-list-col {
  border-right: 1px solid var(--border-grid);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.mohs-list-header {
  padding: 12px 20px;
  border-bottom: 1px solid var(--border-grid);
  background: var(--bg-elevated);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.mohs-mineral-list {
  display: flex;
  flex-direction: column;
}

.mohs-row-btn {
  appearance: none;
  width: 100%;
  background: var(--bg-canvas);
  color: var(--text-primary);
  border: none;
  border-bottom: 1px solid var(--border-grid);
  padding: 14px 20px;
  display: grid;
  grid-template-columns: 48px 150px 1fr 110px;
  align-items: center;
  gap: 14px;
  text-align: left;
  cursor: pointer;
  transition: background-color 0.15s ease;
}

.mohs-row-btn:hover {
  background: var(--bg-surface);
}

.mohs-row-btn.active {
  background: var(--bg-surface);
  box-shadow: inset 4px 0 0 var(--accent);
}

.mohs-row-rank {
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--text-muted);
}

.mohs-row-btn.active .mohs-row-rank {
  color: var(--accent);
}

.mohs-row-title-group {
  display: flex;
  flex-direction: column;
}

.mohs-row-name {
  font-family: var(--font-display);
  font-size: 1.02rem;
  font-weight: 700;
}

.mohs-row-formula {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-muted);
}

.mohs-row-bar-track {
  width: 100%;
  height: 10px;
  background: var(--bg-elevated);
  border: 1px solid var(--border-grid);
  position: relative;
  overflow: hidden;
}

.mohs-row-bar-fill {
  height: 100%;
  background: var(--text-primary);
  transition: width 0.35s var(--ease-out-expo), background-color 0.2s ease;
}

.mohs-row-btn.active .mohs-row-bar-fill {
  background: var(--accent);
}

.mohs-row-metric {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  text-align: right;
  color: var(--text-secondary);
}

/* Everyday Field Kit Reference Strip */
.reference-strip {
  padding: 18px 20px;
  background: var(--bg-surface);
}

.reference-strip-title {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 12px;
  gap: 8px;
  flex-wrap: wrap;
}

.reference-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.ref-pill {
  appearance: none;
  background: var(--bg-canvas);
  color: var(--text-primary);
  border: 1px solid var(--border-grid);
  padding: 6px 10px;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  cursor: pointer;
  transition: border-color 0.15s ease, background-color 0.15s ease;
}

.ref-pill:hover {
  border-color: var(--accent);
  background: var(--bg-elevated);
}

.ref-val {
  color: var(--accent);
  font-weight: 600;
}

/* Right Column: Selected Mineral Dossier */
.mohs-detail-col {
  padding: 32px;
  background: var(--bg-surface);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 24px;
}

.mohs-dossier-top {
  display: grid;
  grid-template-columns: 110px 1fr;
  gap: 20px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--border-grid);
}

.mohs-big-rank-wrap {
  border: 1px solid var(--border-strong);
  background: var(--bg-canvas);
  padding: 12px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.mohs-big-rank {
  font-family: var(--font-display);
  font-size: 3.1rem;
  font-weight: 700;
  line-height: 1;
  color: var(--accent);
  margin-top: 4px;
}

.mohs-formula-row {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 8px;
}

.mohs-chemical-formula {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.mohs-detail-name {
  font-family: var(--font-display);
  font-size: 2.2rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.05;
  margin-bottom: 8px;
}

.mohs-detail-tagline {
  font-size: 0.92rem;
  color: var(--text-secondary);
}

.mohs-visual-row {
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: 20px;
  align-items: stretch;
}

.crystal-viewport {
  border: 1px solid var(--border-grid);
  background: var(--bg-canvas);
  padding: 12px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.crystal-viewport-header {
  display: flex;
  flex-direction: column;
  gap: 2px;
  margin-bottom: 8px;
}

.mohs-crystal-svg {
  width: 100%;
  height: 140px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.mohs-crystal-svg svg {
  width: 128px;
  height: 128px;
}

.hardness-telemetry-box {
  border: 1px solid var(--border-grid);
  background: var(--bg-canvas);
  padding: 16px 18px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 14px;
}

.telemetry-bar-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 6px;
}

.swiss-progress-track {
  width: 100%;
  height: 10px;
  background: var(--bg-elevated);
  border: 1px solid var(--border-grid);
}

.swiss-progress-fill {
  height: 100%;
  background: var(--text-primary);
  transition: width 0.35s var(--ease-out-expo);
}

.swiss-progress-fill.accent-fill {
  background: var(--accent);
}

.telemetry-note {
  font-size: 0.82rem;
  color: var(--text-secondary);
  margin-top: 4px;
  line-height: 1.45;
}

.mohs-spec-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  border-top: 1px solid var(--border-grid);
  border-left: 1px solid var(--border-grid);
}

.spec-cell {
  padding: 12px 16px;
  border-right: 1px solid var(--border-grid);
  border-bottom: 1px solid var(--border-grid);
  background: var(--bg-canvas);
}

.spec-cell-wide {
  grid-column: span 2;
}

.spec-cell dt {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  margin-bottom: 4px;
}

.spec-cell dd {
  font-size: 0.86rem;
  color: var(--text-primary);
  font-weight: 500;
}

.mohs-dossier-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  flex-wrap: wrap;
}

/* ==========================================================================
   SECTION 04: INTERACTIVE SCRATCH TEST LAB
   ========================================================================== */
.scratch-lab-grid {
  display: grid;
  grid-template-columns: 310px 1fr 310px;
}

.scratch-control-col {
  padding: 28px 24px;
  background: var(--bg-surface);
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.scratch-control-col:first-child {
  border-right: 1px solid var(--border-grid);
}

.scratch-control-col:last-child {
  border-left: 1px solid var(--border-grid);
}

.swiss-select {
  width: 100%;
  padding: 12px 14px;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-primary);
  background: var(--bg-canvas);
  border: 1px solid var(--border-strong);
  cursor: pointer;
}

.scratch-specimen-meta {
  border: 1px solid var(--border-grid);
  background: var(--bg-canvas);
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  font-size: 0.85rem;
}

.scratch-stage-col {
  padding: 28px 32px;
  background: var(--bg-canvas);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 16px;
}

.scratch-stage-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
}

.scratch-svg-wrap {
  border: 1px solid var(--border-grid);
  background: var(--bg-surface);
  padding: 12px;
}

#scratch-sim-svg {
  width: 100%;
  max-height: 210px;
  display: block;
}

.sim-target-block {
  fill: var(--bg-elevated);
}

.sim-striker-poly {
  fill: var(--bg-canvas);
}

.scratch-verdict-box {
  padding: 16px 20px;
  border: 1px solid var(--border-strong);
  background: var(--bg-surface);
  font-size: 0.92rem;
}

/* ==========================================================================
   FOOTER
   ========================================================================== */
.site-footer {
  background: var(--bg-surface);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.3fr 1fr 1fr;
}

.footer-col {
  padding: 36px 28px;
  border-right: 1px solid var(--border-grid);
}

.footer-col:last-child {
  border-right: none;
}

.brand-row {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 12px;
}

.footer-copy {
  font-size: 0.86rem;
  color: var(--text-secondary);
  max-width: 48ch;
}

.footer-links {
  list-style: none;
  margin-top: 12px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.footer-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-family: var(--font-mono);
  font-size: 0.76rem;
}

.footer-links a:hover {
  color: var(--accent);
}

.shortcut-list {
  margin-top: 12px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.shortcut-list div {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 0.82rem;
  color: var(--text-secondary);
}

kbd {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  padding: 3px 7px;
  background: var(--bg-canvas);
  border: 1px solid var(--border-strong);
  color: var(--text-primary);
}

/* ==========================================================================
   RESPONSIVE BREAKPOINTS (TABLET & MOBILE)
   ========================================================================== */
@media (max-width: 1120px) {
  .hide-tablet {
    display: none;
  }

  .header-grid {
    grid-template-columns: auto 1fr auto;
  }

  .hero-grid {
    grid-template-columns: 1fr;
  }

  .hero-index-col {
    border-right: none;
    border-bottom: 1px solid var(--border-grid);
    flex-direction: row;
    flex-wrap: wrap;
    align-items: center;
    gap: 20px;
  }

  .hero-vertical-rule {
    display: none;
  }

  .hero-telemetry {
    flex-direction: row;
    flex-wrap: wrap;
    gap: 20px;
  }

  .telemetry-row {
    border-top: none;
    padding-top: 0;
  }

  .hero-main-col {
    border-right: none;
    border-bottom: 1px solid var(--border-grid);
  }

  .section-header-bar {
    grid-template-columns: 120px 1fr;
  }

  .section-controls-col {
    grid-column: span 2;
    border-top: 1px solid var(--border-grid);
    justify-content: flex-start;
    padding: 16px 24px;
  }

  .rock-class-module {
    grid-template-columns: 1fr;
  }

  .rock-class-dossier {
    border-right: none;
    border-bottom: 1px solid var(--border-grid);
  }

  .inspector-grid,
  .cycle-grid,
  .mohs-workspace,
  .scratch-lab-grid {
    grid-template-columns: 1fr;
  }

  .inspector-visual-cell,
  .cycle-diagram-col,
  .mohs-list-col,
  .scratch-control-col:first-child {
    border-right: none;
    border-bottom: 1px solid var(--border-grid);
  }

  .scratch-control-col:last-child {
    border-left: none;
    border-top: 1px solid var(--border-grid);
  }
}

@media (max-width: 760px) {
  .header-grid {
    grid-template-columns: 1fr auto;
  }

  .nav-cell {
    grid-column: span 2;
    border-top: 1px solid var(--border-grid);
    border-right: none;
    overflow-x: auto;
    padding: 4px 12px;
  }

  .brand-sub {
    display: none;
  }

  .hero-main-col {
    padding: 32px 20px;
  }

  .trilogy-overview-strip,
  .specimens-cards-grid,
  .inspector-metrics-grid,
  .mohs-visual-row,
  .mohs-spec-grid,
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .trilogy-overview-card {
    border-right: none;
    border-bottom: 1px solid var(--border-grid);
  }

  .specimen-card {
    border-right: none;
    border-bottom: 1px solid var(--border-grid) !important;
  }

  .spec-cell-wide {
    grid-column: span 1;
  }

  .section-header-bar {
    grid-template-columns: 1fr;
  }

  .section-num-col {
    border-right: none;
    border-bottom: 1px solid var(--border-grid);
    flex-direction: row;
    align-items: baseline;
    padding: 16px 20px;
  }

  .section-title-col,
  .section-controls-col {
    grid-column: span 1;
    padding: 20px;
    border-right: none;
  }

  .mohs-row-btn {
    grid-template-columns: 38px 120px 1fr 80px;
    gap: 8px;
    padding: 12px 14px;
  }

  .mohs-dossier-top {
    grid-template-columns: 1fr;
  }

  .footer-col {
    border-right: none;
    border-bottom: 1px solid var(--border-grid);
  }
}