/* ==========================================================================
   How It Evolved — Studio V2 (FR / EN)
   Modern CSS Architecture (light-dark(), native <dialog>, 2D pan viewport)
   ========================================================================== */

:root {
  /* Raw Light & Dark Color Tokens */
  --bg-light: #f7f6f2;
  --bg-dark: #0d1017;
  --surface-light: #ffffff;
  --surface-dark: #141923;
  --raise-light: #efede7;
  --raise-dark: #1c2331;
  --ink-light: #161920;
  --ink-dark: #ebedf2;
  --muted-light: #4e5564;
  --muted-dark: #9da6b8;
  --faint-light: #767f91;
  --faint-dark: #6c7588;
  --line-light: #dedad0;
  --line-dark: #262f40;
  --accent-light: #b45309;
  --accent-dark: #f59e0b;
  --accent-soft-light: rgba(180, 83, 9, 0.11);
  --accent-soft-dark: rgba(245, 158, 11, 0.15);

  /* Tradition Lane Tokens */
  --lane-judaism-light: #2456a8;
  --lane-judaism-dark: #6396eb;
  --lane-christianity-light: #b83b73;
  --lane-christianity-dark: #e0669e;
  --lane-islam-light: #1b6938;
  --lane-islam-dark: #38a862;
  --lane-hinduism-light: #d96812;
  --lane-hinduism-dark: #f28c38;
  --lane-buddhism-light: #5c469c;
  --lane-buddhism-dark: #a288e3;
  --lane-zoroastrianism-light: #a16207;
  --lane-zoroastrianism-dark: #eab308;
  --lane-sikhism-light: #0369a1;
  --lane-sikhism-dark: #38bdf8;
  --lane-jainism_daoism-light: #0f766e;
  --lane-jainism_daoism-dark: #2dd4bf;

  /* Map Land Token */
  --map-land-light: #e2e0d8;
  --map-land-dark: #222938;

  /* Scrollbar Tokens */
  --scrollbar-thumb-light: #b8b3a6;
  --scrollbar-thumb-dark: #3b465e;
  --scrollbar-track-light: #f0eee8;
  --scrollbar-track-dark: #121620;

  /* Default (Light) Assignments for Legacy Browsers */
  --c-bg: var(--bg-light);
  --c-surface: var(--surface-light);
  --c-raise: var(--raise-light);
  --c-ink: var(--ink-light);
  --c-muted: var(--muted-light);
  --c-faint: var(--faint-light);
  --c-line: var(--line-light);
  --c-accent: var(--accent-light);
  --c-accent-soft: var(--accent-soft-light);
  --lane-judaism: var(--lane-judaism-light);
  --lane-christianity: var(--lane-christianity-light);
  --lane-islam: var(--lane-islam-light);
  --lane-hinduism: var(--lane-hinduism-light);
  --lane-buddhism: var(--lane-buddhism-light);
  --lane-zoroastrianism: var(--lane-zoroastrianism-light);
  --lane-sikhism: var(--lane-sikhism-light);
  --lane-jainism_daoism: var(--lane-jainism_daoism-light);
  --map-land: var(--map-land-light);
  --scrollbar-thumb: var(--scrollbar-thumb-light);
  --scrollbar-track: var(--scrollbar-track-light);

  /* Typography */
  --font-serif: "Source Serif 4", "Iowan Old Style", "Palatino Linotype", Georgia, serif;
  --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: ui-monospace, "SFMono-Regular", Menlo, Monaco, Consolas, monospace;

  /* MANDATORY: Fallback for browsers without light-dark() support */
  @media (prefers-color-scheme: dark) {
    --c-bg: var(--bg-dark);
    --c-surface: var(--surface-dark);
    --c-raise: var(--raise-dark);
    --c-ink: var(--ink-dark);
    --c-muted: var(--muted-dark);
    --c-faint: var(--faint-dark);
    --c-line: var(--line-dark);
    --c-accent: var(--accent-dark);
    --c-accent-soft: var(--accent-soft-dark);
    --lane-judaism: var(--lane-judaism-dark);
    --lane-christianity: var(--lane-christianity-dark);
    --lane-islam: var(--lane-islam-dark);
    --lane-hinduism: var(--lane-hinduism-dark);
    --lane-buddhism: var(--lane-buddhism-dark);
    --lane-zoroastrianism: var(--lane-zoroastrianism-dark);
    --lane-sikhism: var(--lane-sikhism-dark);
    --lane-jainism_daoism: var(--lane-jainism_daoism-dark);
    --map-land: var(--map-land-dark);
    --scrollbar-thumb: var(--scrollbar-thumb-dark);
    --scrollbar-track: var(--scrollbar-track-dark);
  }

  /* Modern light-dark() automatic resolution */
  @supports (color: light-dark(white, black)) {
    --c-bg: light-dark(var(--bg-light), var(--bg-dark));
    --c-surface: light-dark(var(--surface-light), var(--surface-dark));
    --c-raise: light-dark(var(--raise-light), var(--raise-dark));
    --c-ink: light-dark(var(--ink-light), var(--ink-dark));
    --c-muted: light-dark(var(--muted-light), var(--muted-dark));
    --c-faint: light-dark(var(--faint-light), var(--faint-dark));
    --c-line: light-dark(var(--line-light), var(--line-dark));
    --c-accent: light-dark(var(--accent-light), var(--accent-dark));
    --c-accent-soft: light-dark(var(--accent-soft-light), var(--accent-soft-dark));
    --lane-judaism: light-dark(var(--lane-judaism-light), var(--lane-judaism-dark));
    --lane-christianity: light-dark(var(--lane-christianity-light), var(--lane-christianity-dark));
    --lane-islam: light-dark(var(--lane-islam-light), var(--lane-islam-dark));
    --lane-hinduism: light-dark(var(--lane-hinduism-light), var(--lane-hinduism-dark));
    --lane-buddhism: light-dark(var(--lane-buddhism-light), var(--lane-buddhism-dark));
    --lane-zoroastrianism: light-dark(var(--lane-zoroastrianism-light), var(--lane-zoroastrianism-dark));
    --lane-sikhism: light-dark(var(--lane-sikhism-light), var(--lane-sikhism-dark));
    --lane-jainism_daoism: light-dark(var(--lane-jainism_daoism-light), var(--lane-jainism_daoism-dark));
    --map-land: light-dark(var(--map-land-light), var(--map-land-dark));
    --scrollbar-thumb: light-dark(var(--scrollbar-thumb-light), var(--scrollbar-thumb-dark));
    --scrollbar-track: light-dark(var(--scrollbar-track-light), var(--scrollbar-track-dark));
  }

  /* MANDATORY: Apply color-scheme to :root and map <meta name="color-scheme"> override */
  color-scheme: light dark;
  accent-color: var(--c-accent);
  scrollbar-width: thin;
  scrollbar-color: var(--scrollbar-thumb) var(--scrollbar-track);

  &:has(> head > meta[name="color-scheme"][content="dark"]) {
    color-scheme: dark;
  }
  &:has(> head > meta[name="color-scheme"][content="light"]) {
    color-scheme: light;
  }
}

/* Legacy scrollbar fallback for older WebKit/Blink */
@supports not (scrollbar-color: auto) {
  ::-webkit-scrollbar {
    width: 10px;
    height: 10px;
  }
  ::-webkit-scrollbar-thumb {
    background: var(--scrollbar-thumb);
    border-radius: 5px;
  }
  ::-webkit-scrollbar-track {
    background: var(--scrollbar-track);
  }
}

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

body {
  margin: 0;
  background-color: var(--c-bg);
  color: var(--c-ink);
  font-family: var(--font-serif);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

/* Typography & Text Wrapping (improve-text-layout-and-legibility) */
h1, h2, h3, h4 {
  margin: 0;
  font-family: var(--font-serif);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.18;
  text-wrap: balance;
}

p, blockquote, li, .pretty-text {
  margin: 0;
  text-wrap: pretty;
}

a {
  color: inherit;
}

button, input, select {
  font-family: var(--font-sans);
  font-size: inherit;
  color: inherit;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* Theme toggle icon visibility driven purely by CSS color-scheme / meta */
.theme-option-dark {
  display: inline-flex;
}
.theme-option-light {
  display: none;
}
@media (prefers-color-scheme: dark) {
  :root:not(:has(> head > meta[name="color-scheme"][content="light"])) .theme-option-dark {
    display: none;
  }
  :root:not(:has(> head > meta[name="color-scheme"][content="light"])) .theme-option-light {
    display: inline-flex;
  }
}
:root:has(> head > meta[name="color-scheme"][content="dark"]) .theme-option-dark {
  display: none;
}
:root:has(> head > meta[name="color-scheme"][content="dark"]) .theme-option-light {
  display: inline-flex;
}

/* ==========================================================================
   Top Navigation Header
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  background: color-mix(in srgb, var(--c-bg) 88%, transparent);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--c-line);
  font-family: var(--font-sans);
}

.header-inner {
  max-width: 1440px;
  margin: 0 auto;
  padding: 0.65rem 1.25rem;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.85rem;
}

.brand-link {
  display: inline-flex;
  align-items: baseline;
  gap: 0.4rem;
  text-decoration: none;
  font-family: var(--font-serif);
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.brand-accent {
  color: var(--c-accent);
}

.brand-badge {
  font-family: var(--font-sans);
  font-size: 0.68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  padding: 0.15rem 0.45rem;
  border-radius: 999px;
  background: var(--c-accent-soft);
  color: var(--c-accent);
  border: 1px solid color-mix(in srgb, var(--c-accent) 30%, transparent);
}

.author-credit {
  font-family: var(--font-sans);
  font-size: 0.75rem;
  color: var(--c-muted);
  padding: 0.22rem 0.6rem;
  border-radius: 0.45rem;
  background: var(--c-surface);
  border: 1px solid var(--c-line);
  white-space: nowrap;
}

.author-credit a {
  color: var(--c-accent);
  text-decoration: none;
  font-weight: 600;
}

.author-credit a:hover {
  text-decoration: underline;
}

.site-footer {
  margin-top: 2.5rem;
  border-top: 1px solid var(--c-line);
  background: var(--c-surface);
  font-family: var(--font-sans);
  font-size: 0.84rem;
}

.footer-inner {
  max-width: 1440px;
  margin: 0 auto;
  padding: 1.15rem 1.25rem;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
}

.footer-inner a {
  color: var(--c-accent);
  text-decoration: none;
  font-weight: 600;
}

.footer-inner a:hover {
  text-decoration: underline;
}

.view-tabs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.25rem;
  background: var(--c-raise);
  padding: 0.22rem;
  border-radius: 0.6rem;
  border: 1px solid var(--c-line);
}

.view-tab {
  appearance: none;
  border: none;
  background: transparent;
  padding: 0.4rem 0.75rem;
  border-radius: 0.42rem;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--c-muted);
  cursor: pointer;
  transition: background-color 0.15s, color 0.15s;
  display: inline-flex;
  align-items: center;
  gap: 0.38rem;
  white-space: nowrap;
}

.view-tab:hover {
  color: var(--c-ink);
}

.view-tab[aria-selected="true"] {
  background: var(--c-surface);
  color: var(--c-accent);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
}

.header-actions {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 0.45rem;
}

.btn-control {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.38rem 0.7rem;
  border-radius: 0.48rem;
  border: 1px solid var(--c-line);
  background: var(--c-surface);
  color: var(--c-muted);
  font-size: 0.78rem;
  font-weight: 500;
  cursor: pointer;
  text-decoration: none;
  transition: border-color 0.15s, color 0.15s, background-color 0.15s;
}

.btn-control:hover {
  border-color: var(--c-accent);
  color: var(--c-ink);
}

.btn-primary {
  background: var(--c-accent);
  color: #ffffff;
  border-color: var(--c-accent);
  font-weight: 600;
}

.btn-primary:hover {
  filter: brightness(1.08);
  color: #ffffff;
}

.kbd-hint {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  padding: 0.08rem 0.32rem;
  border-radius: 0.25rem;
  background: var(--c-raise);
  border: 1px solid var(--c-line);
  color: var(--c-faint);
}

/* ==========================================================================
   Hero & Global Filter Bar
   ========================================================================== */
.app-shell {
  max-width: 1440px;
  margin: 0 auto;
  padding: 1.25rem;
}

.hero-banner {
  display: grid;
  gap: 1.25rem;
  padding: 1.35rem 1.5rem;
  border-radius: 0.9rem;
  background: var(--c-surface);
  border: 1px solid var(--c-line);
  margin-bottom: 1.25rem;
}

@media (min-width: 1024px) {
  .hero-banner {
    grid-template-columns: 1.45fr 1fr;
    align-items: center;
  }
}

.hero-title {
  font-size: clamp(1.65rem, 2.8vw, 2.45rem);
  color: var(--c-ink);
}

.hero-sub {
  margin-top: 0.55rem;
  font-size: 1rem;
  color: var(--c-muted);
  max-width: 68ch;
}

.stats-strip {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(115px, 1fr));
  gap: 0.65rem;
}

.stat-card {
  padding: 0.75rem 0.85rem;
  border-radius: 0.65rem;
  background: var(--c-raise);
  border: 1px solid var(--c-line);
  font-family: var(--font-sans);
}

.stat-val {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--c-ink);
  font-variant-numeric: tabular-nums;
}

.stat-lbl {
  font-size: 0.72rem;
  color: var(--c-muted);
  margin-top: 0.15rem;
}

/* Global Filter Toolbar */
.filter-toolbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.65rem;
  padding: 0.75rem 1rem;
  border-radius: 0.75rem;
  background: var(--c-surface);
  border: 1px solid var(--c-line);
  margin-bottom: 1.25rem;
  font-family: var(--font-sans);
  font-size: 0.78rem;
}

.filter-group {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.35rem;
}

.filter-label {
  font-weight: 600;
  color: var(--c-faint);
  margin-right: 0.25rem;
  text-transform: uppercase;
  font-size: 0.68rem;
  letter-spacing: 0.05em;
}

.pill-toggle {
  display: inline-flex;
  align-items: center;
  gap: 0.38rem;
  padding: 0.3rem 0.68rem;
  border-radius: 999px;
  border: 1px solid var(--c-line);
  background: var(--c-bg);
  color: var(--c-muted);
  font-size: 0.76rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.15s;
}

.pill-toggle:hover {
  border-color: var(--c-accent);
  color: var(--c-ink);
}

.pill-toggle[aria-pressed="true"] {
  background: var(--c-raise);
  color: var(--c-ink);
  font-weight: 600;
  border-color: var(--pill-color, var(--c-accent));
}

.pill-dot {
  width: 0.55rem;
  height: 0.55rem;
  border-radius: 999px;
  background: var(--pill-color, var(--c-accent));
  opacity: 0.4;
}

.pill-toggle[aria-pressed="true"] .pill-dot {
  opacity: 1;
}

.badge-v2 {
  font-size: 0.62rem;
  font-weight: 700;
  padding: 0.05rem 0.32rem;
  border-radius: 0.25rem;
  background: var(--c-accent-soft);
  color: var(--c-accent);
}

/* ==========================================================================
   Confidence Tags (Academic Consensus Badges)
   ========================================================================== */
.ctag {
  display: inline-flex;
  align-items: center;
  gap: 0.28rem;
  font-family: var(--font-sans);
  font-size: 0.68rem;
  font-weight: 600;
  padding: 0.14rem 0.5rem;
  border-radius: 999px;
  white-space: nowrap;
}

.ctag-consensus {
  background: rgba(22, 163, 74, 0.14);
  color: light-dark(#15803d, #4ade80);
  border: 1px solid rgba(22, 163, 74, 0.3);
}

.ctag-majority {
  background: rgba(37, 99, 235, 0.13);
  color: light-dark(#1d4ed8, #60a5fa);
  border: 1px solid rgba(37, 99, 235, 0.3);
}

.ctag-contested {
  background: rgba(217, 119, 6, 0.15);
  color: light-dark(#b45309, #fbbf24);
  border: 1px solid rgba(217, 119, 6, 0.32);
}

.ctag-speculative {
  background: rgba(147, 51, 234, 0.14);
  color: light-dark(#7e22ce, #c084fc);
  border: 1px solid rgba(147, 51, 234, 0.3);
}

.ctag-political {
  background: rgba(225, 29, 72, 0.14);
  color: light-dark(#be123c, #fb7185);
  border: 1px solid rgba(225, 29, 72, 0.3);
}

/* ==========================================================================
   View 1: Unified Time Synchronizer (Map + Active Branches + Primary Sources)
   ========================================================================== */
.time-controller {
  background: var(--c-surface);
  border: 1px solid var(--c-line);
  border-radius: 0.85rem;
  padding: 1rem 1.25rem;
  margin-bottom: 1.25rem;
  font-family: var(--font-sans);
}

.time-header {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin-bottom: 0.75rem;
}

.current-year-display {
  font-family: var(--font-serif);
  font-size: 1.85rem;
  font-weight: 700;
  color: var(--c-accent);
  font-variant-numeric: tabular-nums;
}

.epoch-presets {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
}

.epoch-btn {
  padding: 0.25rem 0.55rem;
  font-size: 0.72rem;
  border-radius: 0.4rem;
  border: 1px solid var(--c-line);
  background: var(--c-raise);
  color: var(--c-muted);
  cursor: pointer;
}

.epoch-btn:hover {
  border-color: var(--c-accent);
  color: var(--c-ink);
}

.scrubber-row {
  display: flex;
  align-items: center;
  gap: 0.85rem;
}

.scrubber-slider {
  flex: 1;
  height: 0.45rem;
  cursor: pointer;
}

.sync-grid {
  display: grid;
  gap: 1.25rem;
}

@media (min-width: 1100px) {
  .sync-grid {
    grid-template-columns: 1.35fr 1fr;
    align-items: start;
  }
}

.panel-card {
  background: var(--c-surface);
  border: 1px solid var(--c-line);
  border-radius: 0.85rem;
  overflow: hidden;
}

.panel-header {
  padding: 0.85rem 1.15rem;
  border-bottom: 1px solid var(--c-line);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  font-family: var(--font-sans);
}

.panel-title {
  font-size: 0.92rem;
  font-weight: 700;
  color: var(--c-ink);
}

/* Interactive Map Container inside Unified View */
.v2-map-stage {
  position: relative;
  width: 100%;
  aspect-ratio: 1200 / 490;
  background: var(--c-bg);
  overflow: hidden;
  cursor: grab;
}

.v2-map-stage.dragging {
  cursor: grabbing;
}

.v2-map-stage svg {
  display: block;
  width: 100%;
  height: 100%;
}

.v2-map-stage .stop {
  transition: opacity 0.3s;
}
.v2-map-stage .stop[data-state="future"] {
  opacity: 0;
  pointer-events: none;
}
.v2-map-stage .stop[data-state="past"] {
  opacity: 0.35;
}
.v2-map-stage .stop[data-state="past"] .label,
.v2-map-stage .stop[data-state="past"] .lead {
  display: none;
}
.v2-map-stage .pulse {
  fill: currentColor;
  opacity: 0;
  pointer-events: none;
}
.v2-map-stage .stop[data-state="now"] .pulse {
  animation: v2pulse 2.2s ease-out infinite;
  transform-box: fill-box;
  transform-origin: center;
}
@keyframes v2pulse {
  0% { opacity: 0.5; transform: scale(1); }
  100% { opacity: 0; transform: scale(3.2); }
}
.v2-map-stage .trail {
  transition: opacity 0.3s;
}
.v2-map-stage .trail[data-off] {
  opacity: 0;
}
.v2-map-stage .places[data-off] {
  opacity: 0;
  pointer-events: none;
}

/* Active Snapshot Cards */
.snapshot-list {
  padding: 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
  max-height: 680px;
  overflow-y: auto;
}

.tradition-snapshot {
  border: 1px solid var(--c-line);
  border-left: 4px solid var(--trad-color, var(--c-accent));
  border-radius: 0.6rem;
  padding: 0.85rem 1rem;
  background: var(--c-bg);
}

.tradition-snapshot-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.5rem;
  font-family: var(--font-sans);
  margin-bottom: 0.45rem;
}

.tradition-snapshot-name {
  font-weight: 700;
  font-size: 0.92rem;
  color: var(--trad-color, var(--c-ink));
}

.branch-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin-top: 0.45rem;
}

.branch-chip {
  font-family: var(--font-sans);
  font-size: 0.72rem;
  padding: 0.2rem 0.55rem;
  border-radius: 0.38rem;
  background: var(--c-surface);
  border: 1px solid var(--c-line);
  color: var(--c-ink);
  cursor: pointer;
  transition: border-color 0.15s;
}

.branch-chip:hover {
  border-color: var(--c-accent);
  color: var(--c-accent);
}

/* ==========================================================================
   View 2: Interactive Family Tree & Lineage Tracer + 2D Pan Viewport
   ========================================================================== */
/* 2D Panning Surface (follows modern-web-guidance 2d-panning) */
.pan-viewport {
  inline-size: 100%;
  block-size: 72vh;
  overflow: auto;
  scroll-axis-lock: none;
  overscroll-behavior: none;
  background: var(--c-bg);
  border: 1px solid var(--c-line);
  border-radius: 0.75rem;
  position: relative;
}

.pan-viewport:focus-visible {
  outline: 3px solid var(--c-accent);
  outline-offset: 2px;
}

@supports not (scroll-axis-lock: none) {
  .pan-viewport {
    touch-action: none;
  }
}

.lineage-layout {
  display: grid;
  gap: 1.25rem;
}

@media (min-width: 1024px) {
  .lineage-layout {
    grid-template-columns: 340px 1fr;
    align-items: start;
  }
}

.node-directory {
  max-height: 72vh;
  overflow-y: auto;
  padding: 0.75rem;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.node-item-btn {
  width: 100%;
  text-align: left;
  padding: 0.55rem 0.75rem;
  border-radius: 0.5rem;
  border: 1px solid var(--c-line);
  background: var(--c-bg);
  cursor: pointer;
  transition: all 0.15s;
}

.node-item-btn:hover,
.node-item-btn[aria-current="true"] {
  border-color: var(--c-accent);
  background: var(--c-raise);
}

.lineage-chain {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  padding: 1.25rem;
}

.lineage-step {
  position: relative;
  padding: 1rem 1.15rem;
  border-radius: 0.7rem;
  border: 1px solid var(--c-line);
  background: var(--c-bg);
  border-left: 4px solid var(--step-color, var(--c-accent));
}

.lineage-step.active-focus {
  background: var(--c-raise);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.08);
}

/* ==========================================================================
   View 3: Synoptic Split-View Comparator
   ========================================================================== */
.synoptic-controls {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.75rem;
  padding: 1rem 1.25rem;
  background: var(--c-surface);
  border: 1px solid var(--c-line);
  border-radius: 0.85rem;
  margin-bottom: 1.25rem;
  font-family: var(--font-sans);
}

.synoptic-table-wrap {
  overflow-x: auto;
  background: var(--c-surface);
  border: 1px solid var(--c-line);
  border-radius: 0.85rem;
}

.synoptic-grid {
  width: 100%;
  border-collapse: collapse;
  min-width: 780px;
}

.synoptic-grid th,
.synoptic-grid td {
  padding: 0.9rem 1rem;
  border-bottom: 1px solid var(--c-line);
  border-right: 1px solid var(--c-line);
  vertical-align: top;
  text-align: left;
}

.synoptic-grid th {
  font-family: var(--font-sans);
  font-size: 0.85rem;
  background: var(--c-raise);
  position: sticky;
  top: 0;
}

.synoptic-epoch-cell {
  width: 130px;
  font-family: var(--font-sans);
  font-weight: 700;
  font-size: 0.82rem;
  color: var(--c-accent);
  background: color-mix(in srgb, var(--c-raise) 55%, transparent);
  font-variant-numeric: tabular-nums;
}

/* ==========================================================================
   View 4 & 5 & 6: Cards, Chapters, Evidence Ledger & Glossary
   ========================================================================== */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(330px, 1fr));
  gap: 1rem;
}

.chapter-card {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding: 1.15rem 1.25rem;
  border-radius: 0.8rem;
  background: var(--c-surface);
  border: 1px solid var(--c-line);
  transition: border-color 0.15s, transform 0.15s;
  cursor: pointer;
}

.chapter-card:hover {
  border-color: var(--c-accent);
  transform: translateY(-1px);
}

/* ==========================================================================
   Modal Dialogs (follows modern-web-guidance dialog & light-dismiss-a-dialog)
   ========================================================================== */
dialog {
  border: 1px solid var(--c-line);
  border-radius: 0.95rem;
  background: var(--c-surface);
  color: var(--c-ink);
  padding: 0;
  max-width: min(740px, calc(100vw - 2rem));
  width: 100%;
  max-height: calc(100dvh - 3rem);
  box-shadow: 0 24px 48px -12px rgba(0, 0, 0, 0.35);
}

dialog[open] {
  display: flex;
  flex-direction: column;
}

/* MANDATORY: Prevent scroll chaining behind modal dialogs */
dialog:modal {
  overscroll-behavior: contain;
}

dialog::backdrop {
  overflow: hidden;
  overscroll-behavior: contain;
  background-color: rgba(10, 14, 22, 0.58);
  backdrop-filter: blur(3px);
}

.dialog-head {
  padding: 1rem 1.25rem;
  border-bottom: 1px solid var(--c-line);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  font-family: var(--font-sans);
}

.dialog-body {
  padding: 1.25rem;
  overflow-y: auto;
  overscroll-behavior: contain;
}