/* ==========================================================================
   Lethe Learning Portal (learn.kioku.mx / learn.lethedwellers.com)
   Zero-Dependency, Mobile-Optimized, High-Readability Stylesheet
   ========================================================================== */

:root {
  --bg-primary: #080b11;
  --bg-secondary: #0d121c;
  --bg-tertiary: #141b27;
  --bg-card: #101622;
  --border-subtle: #1e293b;
  --border-active: #334155;
  --text-main: #f1f5f9;
  --text-muted: #94a3b8;
  --text-dim: #64748b;
  --accent-emerald: #10b981;
  --accent-cyan: #06b6d4;
  --accent-purple: #a855f7;
  --accent-amber: #f59e0b;
  --accent-red: #ef4444;
  --accent-blue: #3b82f6;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;
  --sidebar-width: 340px;
  --header-height: 56px;
  --audio-bar-height: 64px;
}

body.theme-light {
  --bg-primary: #f8fafc;
  --bg-secondary: #f1f5f9;
  --bg-tertiary: #e2e8f0;
  --bg-card: #ffffff;
  --border-subtle: #cbd5e1;
  --border-active: #94a3b8;
  --text-main: #0f172a;
  --text-muted: #475569;
  --text-dim: #64748b;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  -webkit-tap-highlight-color: transparent;
}

html, body {
  height: 100%;
  font-family: var(--font-sans);
  background-color: var(--bg-primary);
  color: var(--text-main);
  line-height: 1.6;
  font-size: 15px;
  overflow-x: hidden;
}

/* --------------------------------------------------------------------------
   App Shell Layout
   -------------------------------------------------------------------------- */
.app-container {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.app-header {
  height: var(--header-height);
  background-color: var(--bg-secondary);
  border-bottom: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 16px;
  position: sticky;
  top: 0;
  z-index: 50;
}

.header-left, .header-right {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand-container {
  display: flex;
  align-items: center;
  gap: 10px;
  cursor: pointer;
}

.brand-icon {
  font-size: 22px;
}

.brand-title {
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--accent-emerald);
}

.brand-subtitle {
  font-size: 11px;
  color: var(--text-dim);
  display: block;
}

.hub-sync-status {
  display: flex;
  align-items: center;
  gap: 6px;
  background-color: var(--bg-tertiary);
  border: 1px solid var(--border-subtle);
  padding: 4px 10px;
  font-size: 11px;
  font-family: var(--font-mono);
}

.sync-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background-color: var(--accent-emerald);
  box-shadow: 0 0 6px var(--accent-emerald);
}

.btn-icon {
  background: transparent;
  border: 1px solid var(--border-subtle);
  color: var(--text-muted);
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.15s ease;
}

.btn-icon:hover {
  background-color: var(--bg-tertiary);
  color: var(--text-main);
  border-color: var(--border-active);
}

.main-layout {
  display: flex;
  flex: 1;
  position: relative;
}

/* --------------------------------------------------------------------------
   Sidebar (Course & Lesson Navigator)
   -------------------------------------------------------------------------- */
.sidebar {
  width: var(--sidebar-width);
  background-color: var(--bg-secondary);
  border-right: 1px solid var(--border-subtle);
  display: flex;
  flex-direction: column;
  position: sticky;
  top: var(--header-height);
  height: calc(100vh - var(--header-height));
  overflow-y: auto;
  z-index: 40;
}

.sidebar-header {
  padding: 12px;
  border-bottom: 1px solid var(--border-subtle);
}

.search-box {
  display: flex;
  align-items: center;
  gap: 8px;
  background-color: var(--bg-primary);
  border: 1px solid var(--border-subtle);
  padding: 6px 10px;
  color: var(--text-dim);
}

.search-box input {
  background: transparent;
  border: none;
  color: var(--text-main);
  font-size: 13px;
  width: 100%;
  outline: none;
}

.btn-clear {
  background: transparent;
  border: none;
  color: var(--text-dim);
  font-size: 16px;
  cursor: pointer;
}

.course-list-nav {
  padding: 12px;
  border-bottom: 1px solid var(--border-subtle);
}

.nav-heading {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--text-dim);
  margin-bottom: 8px;
}

.course-tab-btn {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: 8px 10px;
  background: transparent;
  border: 1px solid transparent;
  color: var(--text-muted);
  font-size: 13px;
  text-align: left;
  cursor: pointer;
  margin-bottom: 4px;
  transition: all 0.15s ease;
}

.course-tab-btn:hover {
  background-color: var(--bg-tertiary);
  color: var(--text-main);
}

.course-tab-btn.active {
  background-color: var(--bg-tertiary);
  border-color: var(--border-active);
  color: var(--text-main);
  font-weight: 600;
  border-left: 3px solid var(--accent-emerald);
}

.tab-badge {
  font-size: 10px;
  font-family: var(--font-mono);
  padding: 2px 6px;
  background-color: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-subtle);
}

.lesson-hierarchy-nav {
  flex: 1;
  padding: 12px;
  overflow-y: auto;
}

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

.curriculum-title {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-main);
}

.badge-progress {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--accent-emerald);
  background: rgba(16, 185, 129, 0.1);
  padding: 2px 6px;
  border: 1px solid rgba(16, 185, 129, 0.3);
}

/* Tree Nodes */
.week-group {
  margin-bottom: 12px;
}

.week-title-btn {
  width: 100%;
  text-align: left;
  background-color: var(--bg-tertiary);
  border: 1px solid var(--border-subtle);
  padding: 6px 10px;
  font-size: 12px;
  font-weight: 600;
  color: var(--text-main);
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
}

.week-lessons-list {
  list-style: none;
  padding-left: 0;
  margin-top: 4px;
}

.lesson-item-btn {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: 8px 10px;
  background: transparent;
  border: 1px solid transparent;
  color: var(--text-muted);
  font-size: 12.5px;
  text-align: left;
  cursor: pointer;
  margin-bottom: 2px;
}

.lesson-item-btn:hover {
  background-color: var(--bg-tertiary);
  color: var(--text-main);
}

.lesson-item-btn.active {
  background-color: rgba(16, 185, 129, 0.12);
  border-color: rgba(16, 185, 129, 0.4);
  color: var(--accent-emerald);
  font-weight: 600;
}

.lesson-status-icon {
  width: 14px;
  height: 14px;
  margin-right: 6px;
  display: inline-block;
  vertical-align: middle;
}

.sidebar-footer {
  padding: 12px;
  border-top: 1px solid var(--border-subtle);
  background-color: var(--bg-secondary);
}

.pantheon-advisory {
  font-size: 11px;
  color: var(--text-dim);
  display: flex;
  flex-direction: column;
  margin-bottom: 8px;
}

.pantheon-mentor {
  color: var(--accent-purple);
  font-weight: 600;
  font-family: var(--font-mono);
}

.hub-link {
  display: inline-block;
  font-size: 12px;
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.15s;
}

.hub-link:hover {
  color: var(--accent-emerald);
}

/* --------------------------------------------------------------------------
   Content Pane & Reader View
   -------------------------------------------------------------------------- */
.content-pane {
  flex: 1;
  padding: 24px 32px;
  max-width: 960px;
  margin: 0 auto;
  position: relative;
}

.reading-progress-bar-container {
  position: sticky;
  top: var(--header-height);
  left: 0;
  right: 0;
  height: 3px;
  background: transparent;
  z-index: 30;
}

.reading-progress-bar {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--accent-emerald), var(--accent-cyan));
  transition: width 0.1s ease;
}

/* Course Overview Grid */
.overview-hero {
  margin-bottom: 28px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--border-subtle);
}

.hero-badge {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 11px;
  background-color: var(--bg-tertiary);
  border: 1px solid var(--border-subtle);
  padding: 3px 8px;
  color: var(--accent-cyan);
  margin-bottom: 8px;
}

.hero-title {
  font-size: 26px;
  font-weight: 700;
  margin-bottom: 8px;
}

.hero-desc {
  font-size: 14.5px;
  color: var(--text-muted);
  max-width: 720px;
  margin-bottom: 16px;
}

.hero-meta {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.meta-item {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  padding: 6px 12px;
  display: flex;
  flex-direction: column;
}

.meta-label {
  font-size: 10px;
  text-transform: uppercase;
  color: var(--text-dim);
  font-family: var(--font-mono);
}

.meta-val {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-main);
}

.overview-course-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(360px, 1fr));
  gap: 18px;
}

.course-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-subtle);
  padding: 20px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: all 0.2s ease;
}

.course-card:hover {
  border-color: var(--border-active);
  transform: translateY(-2px);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.4);
}

.card-top {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  margin-bottom: 12px;
}

.card-icon {
  font-size: 28px;
}

.card-badge {
  font-family: var(--font-mono);
  font-size: 10px;
  padding: 2px 6px;
  background-color: var(--bg-tertiary);
  border: 1px solid var(--border-subtle);
  color: var(--text-muted);
}

.card-title {
  font-size: 17px;
  font-weight: 700;
  margin-top: 4px;
}

.card-desc {
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 16px;
  line-height: 1.5;
}

.card-progress-bar-wrap {
  height: 6px;
  background-color: var(--bg-tertiary);
  margin-bottom: 12px;
}

.card-progress-bar-fill {
  height: 100%;
  width: 0%;
  transition: width 0.3s ease;
}

.card-bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.btn-open-course {
  background-color: var(--bg-tertiary);
  border: 1px solid var(--border-subtle);
  color: var(--text-main);
  padding: 8px 16px;
  font-size: 12.5px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s ease;
}

.btn-open-course:hover {
  background-color: var(--accent-emerald);
  color: #000;
  border-color: var(--accent-emerald);
}

/* --------------------------------------------------------------------------
   Lesson Reader View Styles
   -------------------------------------------------------------------------- */
.reader-top-controls {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
  gap: 12px;
  flex-wrap: wrap;
}

.btn-secondary {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  color: var(--text-muted);
  padding: 8px 14px;
  font-size: 12.5px;
  cursor: pointer;
}

.btn-secondary:hover {
  background-color: var(--bg-tertiary);
  color: var(--text-main);
}

.reader-actions {
  display: flex;
  gap: 10px;
}

.btn-primary-glow {
  background-color: rgba(6, 182, 212, 0.15);
  border: 1px solid var(--accent-cyan);
  color: var(--accent-cyan);
  padding: 8px 14px;
  font-size: 12.5px;
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 6px;
  cursor: pointer;
  transition: all 0.15s;
}

.btn-primary-glow:hover {
  background-color: var(--accent-cyan);
  color: #000;
}

.btn-toggle-complete {
  background-color: var(--bg-tertiary);
  border: 1px solid var(--border-subtle);
  color: var(--text-muted);
  padding: 8px 14px;
  font-size: 12.5px;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 6px;
}

.btn-toggle-complete.completed {
  background-color: rgba(16, 185, 129, 0.15);
  border-color: var(--accent-emerald);
  color: var(--accent-emerald);
}

.lesson-header-card {
  margin-bottom: 24px;
}

.lesson-meta-breadcrumb {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--text-dim);
  margin-bottom: 8px;
}

.crumb-sep {
  margin: 0 4px;
}

.lesson-main-title {
  font-size: 26px;
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: 12px;
}

.lesson-summary-box {
  background-color: var(--bg-card);
  border-left: 3px solid var(--accent-cyan);
  padding: 12px 16px;
  color: var(--text-muted);
  font-size: 14px;
  line-height: 1.6;
}

/* Objectives */
.objectives-card {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  padding: 16px 20px;
  margin-bottom: 24px;
}

.objectives-title {
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 10px;
  color: var(--text-main);
}

.objectives-list {
  list-style: square;
  padding-left: 20px;
  font-size: 13.5px;
  color: var(--text-muted);
}

.objectives-list li {
  margin-bottom: 6px;
}

/* Lesson Body Markdown Formatting */
.lesson-body-content {
  font-size: 15px;
  line-height: 1.75;
  color: var(--text-main);
  margin-bottom: 32px;
}

.lesson-body-content h3 {
  font-size: 18px;
  margin-top: 28px;
  margin-bottom: 12px;
  color: var(--text-main);
  border-bottom: 1px solid var(--border-subtle);
  padding-bottom: 4px;
}

.lesson-body-content h4 {
  font-size: 16px;
  margin-top: 20px;
  margin-bottom: 8px;
}

.lesson-body-content p {
  margin-bottom: 16px;
}

.lesson-body-content ul, .lesson-body-content ol {
  padding-left: 24px;
  margin-bottom: 16px;
}

.lesson-body-content li {
  margin-bottom: 6px;
}

.lesson-body-content pre {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-subtle);
  padding: 14px 16px;
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.5;
  margin-bottom: 20px;
}

.lesson-body-content code {
  font-family: var(--font-mono);
  font-size: 13px;
  background-color: rgba(255, 255, 255, 0.07);
  padding: 2px 5px;
}

.lesson-body-content pre code {
  background: transparent;
  padding: 0;
}

.lesson-body-content table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 20px;
  font-size: 13.5px;
}

.lesson-body-content th, .lesson-body-content td {
  border: 1px solid var(--border-subtle);
  padding: 8px 12px;
  text-align: left;
}

.lesson-body-content th {
  background-color: var(--bg-tertiary);
  font-weight: 600;
}

/* Thought Experiment Card */
.thought-experiment-card {
  background-color: rgba(245, 158, 11, 0.06);
  border: 1px solid rgba(245, 158, 11, 0.3);
  padding: 18px 20px;
  margin-bottom: 32px;
}

.te-header {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 8px;
}

.te-icon {
  font-size: 20px;
}

.te-title {
  font-size: 14.5px;
  color: var(--accent-amber);
  font-weight: 600;
}

.te-content {
  font-size: 14px;
  color: var(--text-main);
  line-height: 1.6;
}

/* Navigation Footer */
.lesson-nav-footer {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  border-top: 1px solid var(--border-subtle);
  padding-top: 24px;
  margin-bottom: 60px;
}

.btn-nav {
  flex: 1;
  background-color: var(--bg-card);
  border: 1px solid var(--border-subtle);
  padding: 14px 18px;
  cursor: pointer;
  text-align: left;
  display: flex;
  flex-direction: column;
  transition: all 0.15s;
}

.btn-next {
  text-align: right;
}

.btn-nav:hover {
  border-color: var(--border-active);
  background-color: var(--bg-tertiary);
}

.nav-dir {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--text-dim);
  margin-bottom: 4px;
}

.nav-target-title {
  font-size: 13.5px;
  font-weight: 600;
  color: var(--text-main);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

/* --------------------------------------------------------------------------
   Floating On-Demand Audio Player Bar
   -------------------------------------------------------------------------- */
.floating-audio-bar {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  height: var(--audio-bar-height);
  background-color: var(--bg-secondary);
  border-top: 1px solid var(--border-subtle);
  box-shadow: 0 -4px 20px rgba(0, 0, 0, 0.6);
  z-index: 60;
  display: flex;
  flex-direction: column;
}

.audio-bar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 16px;
  flex: 1;
  gap: 16px;
}

.audio-info {
  display: flex;
  align-items: center;
  gap: 10px;
  overflow: hidden;
  max-width: 50%;
}

.audio-icon-speaker {
  font-size: 20px;
  color: var(--accent-cyan);
}

.audio-text-col {
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.audio-title {
  font-size: 12.5px;
  font-weight: 600;
  color: var(--text-main);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.audio-sentence {
  font-size: 11px;
  color: var(--text-dim);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.audio-controls {
  display: flex;
  align-items: center;
  gap: 8px;
}

.btn-audio-ctrl, .btn-audio-play, .btn-speed, .btn-audio-close {
  background-color: var(--bg-tertiary);
  border: 1px solid var(--border-subtle);
  color: var(--text-main);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
}

.btn-audio-ctrl {
  width: 32px;
  height: 32px;
  font-size: 13px;
}

.btn-audio-play {
  width: 40px;
  height: 40px;
  font-size: 16px;
  background-color: var(--accent-cyan);
  color: #000;
  font-weight: bold;
}

.btn-speed {
  padding: 4px 8px;
  font-size: 11px;
  font-family: var(--font-mono);
  height: 32px;
}

.btn-audio-close {
  width: 32px;
  height: 32px;
  font-size: 18px;
  color: var(--text-dim);
}

.audio-scrub-track {
  height: 4px;
  background-color: var(--bg-tertiary);
  width: 100%;
}

.audio-scrub-fill {
  height: 100%;
  width: 0%;
  background-color: var(--accent-cyan);
  transition: width 0.2s ease;
}

/* --------------------------------------------------------------------------
   Mobile Responsive Adjustments
   -------------------------------------------------------------------------- */
@media (max-width: 900px) {
  .sidebar {
    position: fixed;
    top: var(--header-height);
    bottom: 0;
    left: 0;
    transform: translateX(-100%);
    transition: transform 0.25s ease;
    z-index: 100;
    box-shadow: 4px 0 20px rgba(0, 0, 0, 0.7);
  }

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

  .sidebar-backdrop {
    display: none;
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.6);
    z-index: 90;
  }

  .sidebar-backdrop.open {
    display: block;
  }

  .content-pane {
    padding: 16px;
  }

  .overview-course-grid {
    grid-template-columns: 1fr;
  }

  .audio-info {
    max-width: 40%;
  }
}

.hidden {
  display: none !important;
}