/* LTE Signal Path — Design System */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=JetBrains+Mono:wght@400;500;600&display=swap');

:root {
  --font-sans: 'Inter', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;

  --ink-primary: #1a2332;
  --ink-secondary: #4a5568;
  --ink-tertiary: #718096;
  --ink-muted: #a0aec0;

  --canvas: #f7f9fc;
  --surface-1: #ffffff;
  --surface-2: #f1f5f9;
  --surface-inset: #e8edf4;

  --signal-50: #e8f4fd;
  --signal-500: #1a8fe3;
  --signal-600: #1472b8;

  --success: #2d9b5e;
  --warning: #c48a1a;
  --error: #d4534a;
  --info: #1a8fe3;

  --track-foundation: #3b6fd4;
  --track-planning: #0d9b8a;
  --track-ran: #7c5cbf;
  --track-tools: #c48a1a;
  --track-optimize: #d4534a;
  --track-evolution: #2d9b5e;

  --border-subtle: rgba(0, 0, 0, 0.05);
  --border-default: rgba(0, 0, 0, 0.08);
  --border-strong: rgba(0, 0, 0, 0.12);

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;

  --shadow-sm: 0 1px 2px rgba(26, 35, 50, 0.04);
  --shadow-md: 0 4px 12px rgba(26, 35, 50, 0.06);
  --shadow-lg: 0 12px 32px rgba(26, 35, 50, 0.10);
  --shadow-xl: 0 24px 64px rgba(26, 35, 50, 0.16);

  /* Slide deck backdrop + callout fills (themeable) */
  --slides-backdrop: #0f1419;
  --callout-warning-bg: #fef9ee;
  --callout-success-bg: #eef8f2;
  --callout-error-bg: #fdf0ef;

  /* Soft brand wash for headers / hero surfaces */
  --wash: radial-gradient(120% 140% at 0% 0%, rgba(26, 143, 227, 0.07), transparent 55%),
          radial-gradient(120% 140% at 100% 0%, rgba(13, 155, 138, 0.06), transparent 55%);

  --nav-width: 248px;
  --nav-collapsed: 68px;
  --topbar-height: 60px;

  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 24px;
  --space-6: 32px;
  --space-7: 48px;

  --transition: 150ms cubic-bezier(0.4, 0, 0.2, 1);
}

/* ── Dark theme ─────────────────────────────────────────────
   Every surface/ink/border is token-driven, so overriding the
   tokens here re-skins the entire app (incl. slide deck visuals). */
[data-theme="dark"] {
  --ink-primary: #e9eef6;
  --ink-secondary: #aab4c5;
  --ink-tertiary: #7e8ba1;
  --ink-muted: #5c6677;

  --canvas: #0d1117;
  --surface-1: #161c26;
  --surface-2: #1d2532;
  --surface-inset: #232c3b;

  --signal-50: #14283b;
  --signal-500: #3aa0ed;
  --signal-600: #6bbcf5;

  --border-subtle: rgba(255, 255, 255, 0.05);
  --border-default: rgba(255, 255, 255, 0.09);
  --border-strong: rgba(255, 255, 255, 0.16);

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.30);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.38);
  --shadow-lg: 0 12px 32px rgba(0, 0, 0, 0.48);
  --shadow-xl: 0 24px 64px rgba(0, 0, 0, 0.60);

  --slides-backdrop: #05080d;
  --callout-warning-bg: rgba(196, 138, 26, 0.14);
  --callout-success-bg: rgba(45, 155, 94, 0.14);
  --callout-error-bg: rgba(212, 83, 74, 0.16);

  --wash: radial-gradient(120% 140% at 0% 0%, rgba(58, 160, 237, 0.10), transparent 55%),
          radial-gradient(120% 140% at 100% 0%, rgba(13, 155, 138, 0.08), transparent 55%);

  color-scheme: dark;
}

html { transition: background-color var(--transition); }

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { font-size: 16px; scroll-behavior: smooth; }

body {
  font-family: var(--font-sans);
  background: var(--canvas);
  color: var(--ink-primary);
  line-height: 1.5;
  min-height: 100vh;
  overflow-x: hidden;
}

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

/* Layout */
.app-shell {
  display: grid;
  grid-template-columns: var(--nav-width) 1fr;
  min-height: 100vh;
}

.app-shell.nav-collapsed { grid-template-columns: var(--nav-collapsed) 1fr; }

/* Sidebar */
.sidebar {
  background: var(--surface-1);
  border-right: 1px solid var(--border-default);
  display: flex;
  flex-direction: column;
  position: sticky;
  top: 0;
  height: 100vh;
  z-index: 100;
  transition: width var(--transition);
}

.sidebar-brand {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-4) var(--space-4);
  border-bottom: 1px solid var(--border-subtle);
  min-height: var(--topbar-height);
}

.brand-icon {
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, var(--signal-500), var(--track-planning));
  border-radius: var(--radius-sm);
  display: grid;
  place-items: center;
  flex-shrink: 0;
}

.brand-icon svg { width: 20px; height: 20px; color: white; }

.brand-text h1 {
  font-size: 0.9375rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.2;
}

.brand-text span {
  font-size: 0.6875rem;
  color: var(--ink-tertiary);
  font-weight: 500;
}

.nav-collapsed .brand-text { display: none; }

.nav-list {
  list-style: none;
  padding: var(--space-3);
  flex: 1;
  overflow-y: auto;
}

.nav-item button {
  width: 100%;
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: 10px var(--space-3);
  border: none;
  background: transparent;
  border-radius: var(--radius-sm);
  font-family: inherit;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--ink-secondary);
  cursor: pointer;
  transition: background var(--transition), color var(--transition);
  text-align: left;
}

.nav-item button:hover { background: var(--surface-2); color: var(--ink-primary); }
.nav-item button.active { background: var(--signal-50); color: var(--signal-600); }
.nav-item button svg { width: 18px; height: 18px; flex-shrink: 0; }
.nav-collapsed .nav-item button span { display: none; }

.sidebar-footer {
  padding: var(--space-3);
  border-top: 1px solid var(--border-subtle);
}

.progress-summary {
  padding: var(--space-3);
  background: var(--surface-2);
  border-radius: var(--radius-md);
}

.nav-collapsed .progress-summary { display: none; }

.progress-summary-label {
  font-size: 0.6875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--ink-tertiary);
  margin-bottom: var(--space-2);
}

.progress-bar-track {
  height: 6px;
  background: var(--surface-inset);
  border-radius: 99px;
  overflow: hidden;
}

.progress-bar-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--signal-500), var(--track-planning));
  border-radius: 99px;
  transition: width 400ms ease;
}

.progress-pct {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--signal-600);
  margin-top: var(--space-1);
  font-variant-numeric: tabular-nums;
}

/* Main */
.main-area {
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.topbar {
  height: var(--topbar-height);
  background: var(--surface-1);
  border-bottom: 1px solid var(--border-default);
  display: flex;
  align-items: center;
  gap: var(--space-4);
  padding: 0 var(--space-5);
  position: sticky;
  top: 0;
  z-index: 50;
}

.topbar-toggle {
  width: 36px;
  height: 36px;
  border: 1px solid var(--border-default);
  background: var(--surface-1);
  border-radius: var(--radius-sm);
  cursor: pointer;
  display: grid;
  place-items: center;
  color: var(--ink-secondary);
  transition: background var(--transition);
}

.topbar-toggle:hover { background: var(--surface-2); color: var(--ink-primary); }

/* Theme toggle icon swap: moon in light mode, sun in dark mode */
#themeToggle .icon-sun { display: none; }
#themeToggle .icon-moon { display: block; }
[data-theme="dark"] #themeToggle .icon-sun { display: block; }
[data-theme="dark"] #themeToggle .icon-moon { display: none; }

.search-box {
  flex: 1;
  max-width: 420px;
  position: relative;
}

.search-box input {
  width: 100%;
  height: 40px;
  padding: 0 var(--space-4) 0 40px;
  border: 1px solid var(--border-default);
  border-radius: var(--radius-md);
  background: var(--surface-inset);
  font-family: inherit;
  font-size: 0.875rem;
  color: var(--ink-primary);
  transition: border-color var(--transition), box-shadow var(--transition);
}

.search-box input:focus {
  outline: none;
  border-color: var(--signal-500);
  box-shadow: 0 0 0 3px rgba(26, 143, 227, 0.15);
  background: var(--surface-1);
}

.search-box svg {
  position: absolute;
  left: 12px;
  top: 50%;
  transform: translateY(-50%);
  width: 16px;
  height: 16px;
  color: var(--ink-muted);
}

.search-results {
  position: absolute;
  top: calc(100% + 4px);
  left: 0;
  right: 0;
  background: var(--surface-1);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
  max-height: 320px;
  overflow-y: auto;
  display: none;
  z-index: 200;
}

.search-results.open { display: block; }

.search-result-item {
  padding: var(--space-3) var(--space-4);
  cursor: pointer;
  border-bottom: 1px solid var(--border-subtle);
  transition: background var(--transition);
}

.search-result-item:hover { background: var(--surface-2); }
.search-result-item:last-child { border-bottom: none; }

.search-result-item strong {
  display: block;
  font-size: 0.875rem;
  font-weight: 600;
}

.search-result-item span {
  font-size: 0.75rem;
  color: var(--ink-tertiary);
}

.topbar-actions {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin-left: auto;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  height: 36px;
  padding: 0 var(--space-4);
  border-radius: var(--radius-sm);
  font-family: inherit;
  font-size: 0.8125rem;
  font-weight: 600;
  cursor: pointer;
  border: 1px solid transparent;
  transition: background var(--transition), border-color var(--transition), transform var(--transition);
}

.btn:active { transform: scale(0.98); }

.btn-primary {
  background: var(--signal-500);
  color: white;
}

.btn-primary:hover { background: var(--signal-600); }

.btn-secondary {
  background: var(--surface-1);
  border-color: var(--border-default);
  color: var(--ink-primary);
}

.btn-secondary:hover { background: var(--surface-2); }

.btn-ghost {
  background: transparent;
  color: var(--ink-secondary);
}

.btn-ghost:hover { background: var(--surface-2); color: var(--ink-primary); }

/* Spectrum Trace */
.spectrum-trace {
  background: var(--surface-1);
  border-bottom: 1px solid var(--border-subtle);
  padding: var(--space-3) var(--space-5);
}

.spectrum-trace-inner {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  max-width: 1280px;
}

.spectrum-label {
  font-size: 0.6875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--ink-tertiary);
  white-space: nowrap;
  margin-right: var(--space-2);
}

.spectrum-phases {
  display: flex;
  flex: 1;
  gap: 2px;
  height: 8px;
  border-radius: 99px;
  overflow: hidden;
  background: var(--surface-inset);
}

.spectrum-phase {
  flex: 1;
  background: var(--phase-color, var(--surface-inset));
  opacity: 0.35;
  transition: opacity var(--transition), transform var(--transition);
  cursor: pointer;
  position: relative;
}

.spectrum-phase.active { opacity: 1; }
.spectrum-phase.complete { opacity: 0.7; }
.spectrum-phase:hover { opacity: 0.9; transform: scaleY(1.3); }

.spectrum-phase-names {
  display: flex;
  flex: 1;
  gap: 2px;
  margin-top: 4px;
}

.spectrum-phase-name {
  flex: 1;
  font-size: 0.625rem;
  font-weight: 500;
  color: var(--ink-muted);
  text-align: center;
}

.spectrum-phase-name.active { color: var(--ink-primary); font-weight: 600; }

/* Content views */
.view { display: none; padding: var(--space-5); max-width: 1280px; width: 100%; margin: 0 auto; }
.view.active { display: block; animation: fadeIn 250ms ease; }

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}

.page-header { margin-bottom: var(--space-6); }

.page-header h2 {
  font-size: clamp(1.5rem, 1.1rem + 1.6vw, 1.9rem);
  font-weight: 700;
  letter-spacing: -0.025em;
  line-height: 1.2;
}

.page-header p {
  color: var(--ink-secondary);
  font-size: 0.9375rem;
  margin-top: var(--space-2);
  max-width: 640px;
}

/* Dashboard grid */
.dashboard-grid {
  display: grid;
  gap: var(--space-5);
}

.hero-card {
  background: var(--wash), var(--surface-1);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  box-shadow: var(--shadow-md);
}

.hero-card-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: var(--space-5);
}

.hero-card-header h3 {
  font-size: 1.125rem;
  font-weight: 600;
}

/* Journey Map */
.journey-map {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.journey-track {
  display: flex;
  align-items: stretch;
  gap: var(--space-3);
}

.track-label {
  width: 140px;
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding-right: var(--space-3);
  border-right: 3px solid var(--track-color);
}

.track-label span {
  font-size: 0.6875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--track-color);
}

.track-label strong {
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--ink-primary);
  margin-top: 2px;
}

.track-nodes {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  flex: 1;
  align-items: center;
}

.journey-node {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-md);
  border: 2px solid var(--border-default);
  background: var(--surface-2);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: border-color var(--transition), background var(--transition), transform var(--transition);
  position: relative;
}

.journey-node:hover {
  border-color: var(--track-color);
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

.journey-node.complete {
  border-color: var(--track-color);
  background: color-mix(in srgb, var(--track-color) 12%, white);
}

.journey-node.in-progress {
  border-color: var(--track-color);
  background: var(--surface-1);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--track-color) 20%, transparent);
}

.journey-node .day-num {
  font-size: 0.6875rem;
  font-weight: 700;
  color: var(--track-color);
  font-variant-numeric: tabular-nums;
}

.journey-node .day-label {
  font-size: 0.5625rem;
  color: var(--ink-tertiary);
  font-weight: 500;
}

.journey-node .check {
  position: absolute;
  top: -4px;
  right: -4px;
  width: 16px;
  height: 16px;
  background: var(--success);
  border-radius: 50%;
  display: none;
  place-items: center;
}

.journey-node.complete .check { display: grid; }
.journey-node .check svg { width: 10px; height: 10px; color: white; }

/* Cards row */
.cards-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-4);
}

@media (max-width: 1100px) {
  .cards-row { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 768px) {
  .cards-row { grid-template-columns: 1fr; }
  .app-shell { grid-template-columns: 1fr; }
  .sidebar { display: none; }
  .sidebar.mobile-open {
    display: flex;
    position: fixed;
    left: 0;
    top: 0;
    width: var(--nav-width);
    box-shadow: var(--shadow-md);
  }
}

.card {
  background: var(--surface-1);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
  display: flex;
  flex-direction: column;
  transition: border-color var(--transition), box-shadow var(--transition), transform var(--transition);
}

.card:hover {
  border-color: var(--border-strong);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.card-label {
  font-size: 0.6875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--ink-tertiary);
  margin-bottom: var(--space-2);
}

.card h4 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: var(--space-2);
}

.card p {
  font-size: 0.8125rem;
  color: var(--ink-secondary);
  line-height: 1.55;
}

.card-meta {
  display: flex;
  gap: var(--space-2);
  margin-top: var(--space-3);
  flex-wrap: wrap;
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 2px 8px;
  border-radius: 99px;
  font-size: 0.6875rem;
  font-weight: 600;
  background: var(--surface-2);
  color: var(--ink-secondary);
}

.chip.track { color: white; }

/* Knowledge cards */
.knowledge-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: var(--space-3);
}

.knowledge-card {
  background: var(--surface-1);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-md);
  padding: var(--space-4);
  cursor: pointer;
  transition: border-color var(--transition), transform var(--transition);
}

.knowledge-card:hover {
  border-color: var(--signal-500);
  transform: translateY(-1px);
}

.knowledge-card .term {
  font-family: var(--font-mono);
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--signal-600);
  margin-bottom: var(--space-2);
}

.knowledge-card p {
  font-size: 0.8125rem;
  color: var(--ink-secondary);
  line-height: 1.5;
}

/* Callouts */
.callout {
  border-left: 3px solid var(--info);
  background: var(--signal-50);
  padding: var(--space-3) var(--space-4);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin: var(--space-4) 0;
}

.callout.warning { border-color: var(--warning); background: var(--callout-warning-bg); }
.callout.success { border-color: var(--success); background: var(--callout-success-bg); }

.callout-label {
  font-size: 0.6875rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--space-1);
}

.callout.info .callout-label { color: var(--info); }
.callout.warning .callout-label { color: var(--warning); }
.callout.success .callout-label { color: var(--success); }

/* Module view */
.module-layout {
  display: grid;
  grid-template-columns: 220px 1fr 280px;
  gap: var(--space-5);
  align-items: start;
}

@media (max-width: 1024px) {
  .module-layout { grid-template-columns: 1fr; }
}

.module-toc {
  position: sticky;
  top: calc(var(--topbar-height) + var(--space-5));
  background: var(--surface-1);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
}

.module-toc h4 {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--ink-tertiary);
  margin-bottom: var(--space-3);
}

.toc-item {
  display: block;
  padding: var(--space-2) var(--space-3);
  font-size: 0.8125rem;
  color: var(--ink-secondary);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: background var(--transition), color var(--transition);
  border: none;
  background: none;
  width: 100%;
  text-align: left;
  font-family: inherit;
}

.toc-item:hover { background: var(--surface-2); color: var(--ink-primary); }
.toc-item.active { background: var(--signal-50); color: var(--signal-600); font-weight: 600; }

.module-content {
  background: var(--surface-1);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
}

.module-content h3 {
  font-size: 1.375rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: var(--space-4);
}

.objectives-list {
  list-style: none;
  margin-bottom: var(--space-5);
}

.objectives-list li {
  padding: var(--space-2) 0 var(--space-2) var(--space-5);
  font-size: 0.875rem;
  color: var(--ink-secondary);
  position: relative;
  border-bottom: 1px solid var(--border-subtle);
}

.objectives-list li::before {
  content: '✓';
  position: absolute;
  left: 0;
  color: var(--success);
  font-weight: 700;
  font-size: 0.75rem;
}

.section-block {
  margin-bottom: var(--space-5);
  padding-bottom: var(--space-5);
  border-bottom: 1px solid var(--border-subtle);
}

.section-block:last-child { border-bottom: none; margin-bottom: 0; padding-bottom: 0; }

.section-block h4 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: var(--space-3);
}

.concept-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-top: var(--space-3);
}

.concept-tag {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  padding: 4px 10px;
  background: var(--surface-2);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-sm);
  color: var(--ink-secondary);
  cursor: pointer;
  transition: border-color var(--transition);
}

.concept-tag:hover { border-color: var(--signal-500); color: var(--signal-600); }

.module-sidebar {
  position: sticky;
  top: calc(var(--topbar-height) + var(--space-5));
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.param-card {
  background: var(--surface-inset);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-md);
  padding: var(--space-3);
}

.param-card .param-name {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--signal-600);
}

.param-card .param-value {
  font-size: 1.125rem;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  margin: var(--space-1) 0;
}

.param-card .param-desc {
  font-size: 0.75rem;
  color: var(--ink-tertiary);
}

/* Slide deck */
.slides-view {
  padding: 0 !important;
  max-width: none !important;
}

.slides-container {
  display: grid;
  grid-template-columns: 260px 1fr;
  min-height: calc(100vh - var(--topbar-height) - 52px);
}

@media (max-width: 900px) {
  .slides-container { grid-template-columns: 1fr; }
  .slides-sidebar { display: none; }
}

.slides-sidebar {
  background: var(--surface-1);
  border-right: 1px solid var(--border-default);
  padding: var(--space-4);
  overflow-y: auto;
  max-height: calc(100vh - var(--topbar-height) - 52px);
}

.slides-sidebar h4 {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--ink-tertiary);
  margin-bottom: var(--space-3);
}

.slide-nav-section {
  margin-bottom: var(--space-4);
}

.slide-nav-section-title {
  font-size: 0.6875rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--ink-muted);
  padding: var(--space-2) 0;
}

.slide-nav-item {
  display: block;
  width: 100%;
  padding: var(--space-2) var(--space-3);
  border: none;
  background: transparent;
  border-radius: var(--radius-sm);
  font-family: inherit;
  font-size: 0.8125rem;
  color: var(--ink-secondary);
  text-align: left;
  cursor: pointer;
  transition: background var(--transition);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.slide-nav-item:hover { background: var(--surface-2); }
.slide-nav-item.active { background: var(--signal-50); color: var(--signal-600); font-weight: 600; }

.slides-main {
  display: flex;
  flex-direction: column;
  background: var(--slides-backdrop);
  transition: background-color var(--transition);
}

.slide-viewport {
  flex: 1;
  display: grid;
  place-items: center;
  padding: var(--space-5);
  min-height: 480px;
}

.slide-frame {
  width: 100%;
  max-width: 960px;
  aspect-ratio: 16 / 9;
  background: var(--surface-1);
  border-radius: var(--radius-lg);
  box-shadow: 0 24px 64px rgba(0, 0, 0, 0.4);
  padding: var(--space-6);
  display: flex;
  flex-direction: column;
  position: relative;
  overflow: hidden;
}

.slide-frame::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--signal-500), var(--track-planning), var(--track-ran));
}

/* Slide enter transition — re-triggered on every render via class toggle */
@keyframes slideIn {
  from { opacity: 0; transform: translateY(14px) scale(0.99); }
  to   { opacity: 1; transform: translateY(0) scale(1); }
}

.slide-frame.animate-in { animation: slideIn 340ms cubic-bezier(0.22, 1, 0.36, 1); }

/* Fragment stagger — each bullet eases in after the slide settles */
@keyframes fragIn {
  from { opacity: 0; transform: translateX(-10px); }
  to   { opacity: 1; transform: translateX(0); }
}

.slide-frame.animate-in .slide-content li {
  animation: fragIn 360ms ease both;
  animation-delay: calc(var(--i, 0) * 70ms + 140ms);
}

.slide-frame.animate-in .slide-visual {
  animation: fragIn 420ms ease both;
  animation-delay: 200ms;
}

/* Present / fullscreen mode */
.slides-main:fullscreen,
.slides-main:-webkit-full-screen {
  padding: 0;
  justify-content: center;
}

.slides-main:fullscreen .slide-viewport { padding: var(--space-6); }
.slides-main:fullscreen .slide-frame { max-width: min(1200px, 92vw); }

.slide-section-tag {
  font-size: 0.6875rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--signal-600);
  margin-bottom: var(--space-3);
}

.slide-title {
  font-size: clamp(1.25rem, 2.5vw, 1.75rem);
  font-weight: 700;
  letter-spacing: -0.025em;
  line-height: 1.2;
  margin-bottom: var(--space-4);
}

.slide-body {
  flex: 1;
  display: flex;
  gap: var(--space-5);
}

.slide-content {
  flex: 1;
}

.slide-content ul {
  list-style: none;
}

.slide-content li {
  padding: var(--space-2) 0 var(--space-2) var(--space-5);
  font-size: 0.9375rem;
  color: var(--ink-secondary);
  position: relative;
  line-height: 1.5;
}

.slide-content li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.85em;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--signal-500);
}

.slide-visual {
  flex: 0 0 42%;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* Slide visual components */
.vis-timeline {
  width: 100%;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.vis-timeline-item {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-2) var(--space-3);
  background: var(--surface-2);
  border-radius: var(--radius-sm);
  border-left: 3px solid var(--signal-500);
  font-size: 0.75rem;
  font-weight: 500;
}

.vis-arch {
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-2);
}

.vis-arch-row {
  display: flex;
  gap: var(--space-2);
  justify-content: center;
}

.vis-arch-box {
  padding: var(--space-2) var(--space-3);
  background: var(--signal-50);
  border: 1px solid var(--signal-500);
  border-radius: var(--radius-sm);
  font-size: 0.6875rem;
  font-weight: 600;
  color: var(--signal-600);
  text-align: center;
}

.vis-arch-arrow {
  font-size: 1rem;
  color: var(--ink-muted);
}

.vis-bento {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-2);
  width: 100%;
}

.vis-bento-item {
  padding: var(--space-3);
  background: var(--surface-2);
  border-radius: var(--radius-sm);
  font-size: 0.6875rem;
  font-weight: 600;
  text-align: center;
  border: 1px solid var(--border-default);
}

/* Subtle hover lift across slide visual blocks */
.vis-timeline-item,
.vis-bento-item,
.vis-arch-box,
.vis-flow-step {
  transition: transform var(--transition), border-color var(--transition), box-shadow var(--transition);
}

.vis-timeline-item:hover,
.vis-bento-item:hover,
.vis-arch-box:hover,
.vis-flow-step:hover {
  transform: translateY(-2px);
  border-color: var(--signal-500);
  box-shadow: var(--shadow-sm);
}

.vis-prb {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 2px;
  width: 100%;
}

.vis-prb-cell {
  aspect-ratio: 1;
  background: var(--surface-2);
  border: 1px solid var(--border-default);
  border-radius: 2px;
  font-size: 0.5rem;
  display: grid;
  place-items: center;
  color: var(--ink-muted);
}

.vis-prb-cell.active {
  background: var(--signal-50);
  border-color: var(--signal-500);
  color: var(--signal-600);
  font-weight: 700;
}

.vis-flow {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  width: 100%;
}

.vis-flow-step {
  padding: var(--space-2) var(--space-3);
  background: var(--surface-2);
  border-radius: var(--radius-sm);
  font-size: 0.6875rem;
  font-weight: 500;
  text-align: center;
  position: relative;
}

.vis-flow-step::after {
  content: '↓';
  display: block;
  text-align: center;
  color: var(--ink-muted);
  font-size: 0.75rem;
  margin-top: 2px;
}

.vis-flow-step:last-child::after { display: none; }

.vis-hub {
  display: grid;
  place-items: center;
  width: 100%;
  position: relative;
  height: 160px;
}

.vis-hub-center {
  width: 72px;
  height: 72px;
  background: var(--signal-500);
  color: white;
  border-radius: 50%;
  display: grid;
  place-items: center;
  font-size: 0.625rem;
  font-weight: 700;
  text-align: center;
  z-index: 2;
}

.vis-hub-orbit {
  position: absolute;
  padding: var(--space-1) var(--space-2);
  background: var(--surface-2);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-sm);
  font-size: 0.5625rem;
  font-weight: 600;
  white-space: nowrap;
}

.vis-hub-orbit:nth-child(2) { top: 0; left: 50%; transform: translateX(-50%); }
.vis-hub-orbit:nth-child(3) { top: 30%; right: 0; }
.vis-hub-orbit:nth-child(4) { bottom: 0; right: 20%; }
.vis-hub-orbit:nth-child(5) { bottom: 0; left: 20%; }
.vis-hub-orbit:nth-child(6) { top: 30%; left: 0; }

.vis-matrix {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-2);
  width: 100%;
}

.vis-matrix-cell {
  padding: var(--space-2);
  background: var(--surface-2);
  border-radius: var(--radius-sm);
  font-size: 0.625rem;
  font-weight: 600;
  text-align: center;
  border: 1px solid var(--border-default);
}

.vis-matrix-cell.highlight {
  background: var(--signal-50);
  border-color: var(--signal-500);
  color: var(--signal-600);
}

.slide-controls {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-4);
  padding: var(--space-4) var(--space-5);
  background: rgba(255, 255, 255, 0.04);
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.slide-counter {
  font-size: 0.8125rem;
  color: rgba(255, 255, 255, 0.6);
  font-variant-numeric: tabular-nums;
  min-width: 80px;
  text-align: center;
}

.slide-controls .btn {
  background: rgba(255, 255, 255, 0.1);
  color: white;
  border-color: rgba(255, 255, 255, 0.15);
}

.slide-controls .btn:hover { background: rgba(255, 255, 255, 0.18); }
.slide-controls .btn:disabled { opacity: 0.35; cursor: not-allowed; }

/* Concept drawer */
.drawer-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.3);
  z-index: 300;
  opacity: 0;
  pointer-events: none;
  transition: opacity 250ms ease;
}

.drawer-overlay.open { opacity: 1; pointer-events: auto; }

.drawer {
  position: fixed;
  top: 0;
  right: 0;
  width: 380px;
  max-width: 90vw;
  height: 100vh;
  background: var(--surface-1);
  border-left: 1px solid var(--border-default);
  box-shadow: var(--shadow-md);
  z-index: 301;
  transform: translateX(100%);
  transition: transform 250ms ease;
  padding: var(--space-5);
  overflow-y: auto;
}

.drawer.open { transform: translateX(0); }

.drawer-close {
  position: absolute;
  top: var(--space-4);
  right: var(--space-4);
  width: 32px;
  height: 32px;
  border: 1px solid var(--border-default);
  background: var(--surface-1);
  border-radius: var(--radius-sm);
  cursor: pointer;
  display: grid;
  place-items: center;
}

.drawer h3 {
  font-family: var(--font-mono);
  font-size: 1.125rem;
  color: var(--signal-600);
  margin-bottom: var(--space-3);
  padding-right: var(--space-6);
}

/* Quiz interaction */
.quiz-options {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  margin-top: var(--space-3);
}

.quiz-option {
  padding: var(--space-3) var(--space-4);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-sm);
  background: var(--surface-2);
  font-size: 0.875rem;
  cursor: pointer;
  transition: border-color var(--transition), background var(--transition);
  text-align: left;
  font-family: inherit;
}

.quiz-option:hover { border-color: var(--signal-500); }
.quiz-option.correct { border-color: var(--success); background: var(--callout-success-bg); }
.quiz-option.wrong { border-color: var(--error); background: var(--callout-error-bg); }

/* Tracks filter */
.filter-bar {
  display: flex;
  gap: var(--space-2);
  flex-wrap: wrap;
  margin-bottom: var(--space-4);
}

.filter-chip {
  padding: 6px 14px;
  border-radius: 99px;
  border: 1px solid var(--border-default);
  background: var(--surface-1);
  font-size: 0.8125rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition);
  font-family: inherit;
  color: var(--ink-secondary);
}

.filter-chip:hover { border-color: var(--border-strong); }
.filter-chip.active {
  background: var(--signal-50);
  border-color: var(--signal-500);
  color: var(--signal-600);
  font-weight: 600;
}

/* Module list */
.module-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.module-list-item {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  padding: var(--space-4);
  background: var(--surface-1);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-lg);
  cursor: pointer;
  transition: border-color var(--transition), box-shadow var(--transition);
}

.module-list-item:hover {
  border-color: var(--border-strong);
  box-shadow: var(--shadow-sm);
}

.module-day-badge {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  display: grid;
  place-items: center;
  font-weight: 700;
  font-size: 0.875rem;
  color: white;
  flex-shrink: 0;
}

.module-list-info { flex: 1; min-width: 0; }
.module-list-info h4 { font-size: 1rem; font-weight: 600; }
.module-list-info p { font-size: 0.8125rem; color: var(--ink-tertiary); margin-top: 2px; }

.module-list-actions {
  display: flex;
  gap: var(--space-2);
  flex-shrink: 0;
}

/* Toast */
.toast {
  position: fixed;
  bottom: var(--space-5);
  right: var(--space-5);
  padding: var(--space-3) var(--space-4);
  background: var(--ink-primary);
  color: var(--canvas);
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  font-weight: 500;
  box-shadow: var(--shadow-lg);
  z-index: 400;
  transform: translateY(100px);
  opacity: 0;
  transition: transform 300ms ease, opacity 300ms ease;
}

.toast.show { transform: translateY(0); opacity: 1; }

/* ── Compact / small-screen refinements ─────────────────────── */
@media (max-width: 900px) {
  .slides-main { min-height: calc(100vh - var(--topbar-height)); }
}

@media (max-width: 640px) {
  .view { padding: var(--space-4); }
  .topbar { padding: 0 var(--space-4); gap: var(--space-3); }
  .slide-body { flex-direction: column; gap: var(--space-3); }
  .slide-visual { flex: 0 0 auto; width: 100%; }
  .slide-frame { aspect-ratio: auto; min-height: 60vh; }
  .slide-controls { gap: var(--space-2); padding: var(--space-3); flex-wrap: wrap; }
  .toast { left: var(--space-4); right: var(--space-4); bottom: var(--space-4); text-align: center; }
}