@import url('https://fonts.googleapis.com/css2?family=Plus+Jakarta+Sans:wght@300;400;500;600;700;800&family=Lora:ital,wght@0,400;0,500;1,400&family=JetBrains+Mono:wght@400;500&display=swap');

:root {
  /* Minimalist Editorial Dark Theme */
  --bg-app: #0e1117;
  --bg-surface: #151922;
  --bg-surface-elevated: #1c212c;
  --bg-surface-subtle: rgba(255, 255, 255, 0.03);
  
  --border-subtle: #242b3b;
  --border-strong: #323b4f;
  --border-focus: #4f46e5;
  
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --text-accent: #818cf8;
  
  --color-primary: #4f46e5;
  --color-primary-soft: rgba(79, 70, 229, 0.1);
  --color-success: #10b981;
  --color-success-soft: rgba(16, 185, 129, 0.1);
  --color-warning: #f59e0b;
  --color-warning-soft: rgba(245, 158, 11, 0.1);
  
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  
  --shadow-subtle: 0 1px 3px rgba(0, 0, 0, 0.2);
  --shadow-card: 0 4px 20px rgba(0, 0, 0, 0.25);
  
  --font-sans: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-serif: 'Lora', Georgia, serif;
  --font-mono: 'JetBrains Mono', monospace;
  
  --transition: all 0.2s ease;
}

/* Light Theme (Clean Minimalist Paper) */
body.light-theme {
  --bg-app: #f8fafc;
  --bg-surface: #ffffff;
  --bg-surface-elevated: #f1f5f9;
  --bg-surface-subtle: rgba(0, 0, 0, 0.02);
  
  --border-subtle: #e2e8f0;
  --border-strong: #cbd5e1;
  --border-focus: #4f46e5;
  
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  --text-accent: #4f46e5;
  
  --color-primary: #4f46e5;
  --color-primary-soft: #eef2ff;
  --color-success: #059669;
  --color-success-soft: #ecfdf5;
  --color-warning: #d97706;
  --color-warning-soft: #fffbeb;
  
  --shadow-subtle: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-card: 0 4px 16px rgba(0, 0, 0, 0.06);
}

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

html, body {
  width: 100%;
  min-height: 100%;
  font-family: var(--font-sans);
  background-color: var(--bg-app);
  color: var(--text-primary);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

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

/* Minimal Top Navbar */
.top-navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 32px;
  background: var(--bg-surface);
  border-bottom: 1px solid var(--border-subtle);
  box-shadow: var(--shadow-subtle);
}

.brand-section {
  display: flex;
  align-items: center;
  gap: 12px;
  cursor: pointer;
}

.brand-logo-icon {
  font-size: 1.25rem;
  background: var(--color-primary-soft);
  color: var(--text-accent);
  width: 34px;
  height: 34px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-subtle);
}

.brand-info h1 {
  font-size: 0.95rem;
  font-weight: 700;
  letter-spacing: -0.2px;
  color: var(--text-primary);
}

.brand-info p {
  font-size: 0.75rem;
  color: var(--text-secondary);
}

.nav-center-progress {
  display: flex;
  align-items: center;
  gap: 18px;
}

.slide-counter-badge {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-secondary);
  background: var(--bg-surface-elevated);
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-subtle);
}

.global-progress-bar-wrapper {
  width: 200px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.progress-labels {
  display: flex;
  justify-content: space-between;
  font-size: 0.72rem;
  color: var(--text-secondary);
  font-weight: 600;
}

.progress-track {
  width: 100%;
  height: 4px;
  background: var(--bg-surface-elevated);
  border-radius: 2px;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: var(--color-primary);
  width: 0%;
  transition: width 0.3s ease;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

.btn-icon {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  color: var(--text-secondary);
  padding: 7px 12px;
  border-radius: var(--radius-sm);
  font-family: var(--font-sans);
  font-size: 0.82rem;
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 6px;
  cursor: pointer;
  transition: var(--transition);
}

.btn-icon:hover {
  background: var(--bg-surface-elevated);
  color: var(--text-primary);
  border-color: var(--border-strong);
}

.btn-icon.active {
  background: var(--color-primary-soft);
  color: var(--text-accent);
  border-color: var(--color-primary);
}

/* Main Slide Canvas */
.slide-stage {
  flex: 1;
  display: flex;
  justify-content: center;
  padding: 36px 24px 60px;
  max-width: 1080px;
  width: 100%;
  margin: 0 auto;
}

.slide-card {
  width: 100%;
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 44px 48px;
  box-shadow: var(--shadow-card);
}

/* Header */
.slide-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 24px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--border-subtle);
}

.chapter-meta {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 10px;
}

.chapter-tag {
  background: var(--color-primary-soft);
  color: var(--text-accent);
  border: 1px solid var(--border-subtle);
  font-size: 0.72rem;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.original-title {
  font-size: 0.82rem;
  color: var(--text-muted);
}

.read-time {
  font-size: 0.75rem;
  color: var(--text-muted);
  background: var(--bg-surface-elevated);
  padding: 2px 8px;
  border-radius: var(--radius-sm);
}

.chapter-main-title {
  font-size: 1.85rem;
  font-weight: 800;
  letter-spacing: -0.5px;
  line-height: 1.3;
  color: var(--text-primary);
}

.slide-status-badge {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 5px 12px;
  border-radius: var(--radius-sm);
  font-size: 0.78rem;
  font-weight: 600;
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-subtle);
  color: var(--text-muted);
  white-space: nowrap;
}

.slide-status-badge.completed {
  background: var(--color-success-soft);
  border-color: var(--color-success);
  color: var(--color-success);
}

/* Chapter Context Box */
.context-box {
  background: var(--bg-surface-subtle);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 16px 20px;
  margin-bottom: 24px;
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.context-box strong {
  color: var(--text-primary);
}

/* Quote Section */
.quote-box {
  background: var(--bg-surface-elevated);
  border-left: 3px solid var(--text-muted);
  padding: 18px 24px;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  margin-bottom: 26px;
}

.quote-box p {
  font-family: var(--font-serif);
  font-size: 1.05rem;
  font-style: italic;
  color: var(--text-primary);
  line-height: 1.6;
  margin-bottom: 6px;
}

.quote-author {
  font-family: var(--font-sans);
  font-size: 0.78rem;
  color: var(--text-secondary);
  font-weight: 600;
  text-align: right;
  display: block;
}

/* Core Takeaway Box */
.core-takeaway-banner {
  background: var(--color-primary-soft);
  border: 1px solid rgba(79, 70, 229, 0.2);
  border-radius: var(--radius-md);
  padding: 18px 22px;
  margin-bottom: 32px;
  display: flex;
  align-items: flex-start;
  gap: 14px;
}

.takeaway-icon {
  font-size: 1.3rem;
  flex-shrink: 0;
  line-height: 1.2;
}

.takeaway-content h4 {
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.8px;
  color: var(--text-accent);
  margin-bottom: 4px;
  font-weight: 700;
}

.takeaway-content p {
  font-size: 0.98rem;
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1.5;
}

/* Key Insights */
.section-heading {
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: -0.2px;
  color: var(--text-primary);
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.keypoints-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  margin-bottom: 32px;
}

.keypoint-card {
  background: var(--bg-surface-subtle);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 18px 22px;
  transition: var(--transition);
}

.keypoint-card:hover {
  border-color: var(--border-strong);
  background: var(--bg-surface-elevated);
}

.keypoint-card h4 {
  font-size: 0.96rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 6px;
}

.keypoint-card p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* Diagrams */
.diagram-box {
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 22px 24px;
  margin-bottom: 32px;
}

.diagram-title {
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--text-secondary);
  margin-bottom: 16px;
  text-transform: uppercase;
  letter-spacing: 0.8px;
}

.flow-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  overflow-x: auto;
  padding: 6px 0;
}

.flow-step {
  flex: 1;
  min-width: 150px;
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 12px 14px;
  text-align: left;
}

.flow-step-label {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 2px;
}

.flow-step-sub {
  font-size: 0.74rem;
  color: var(--text-muted);
}

.flow-arrow {
  color: var(--text-muted);
  font-size: 1rem;
}

/* Comparisons */
.comparison-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.comparison-item {
  display: grid;
  grid-template-columns: 200px 1fr;
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.comp-cat {
  background: var(--bg-surface-subtle);
  padding: 12px 16px;
  font-weight: 700;
  font-size: 0.82rem;
  color: var(--text-primary);
  border-right: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
}

.comp-detail {
  padding: 12px 16px;
  font-size: 0.86rem;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
}

/* Flow Channel */
.flow-channel-visual {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  padding: 18px;
}

.flow-axis-label {
  font-size: 0.74rem;
  color: var(--text-muted);
  font-weight: 600;
  margin-bottom: 10px;
}

.flow-zones {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.flow-zone-item {
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.zone-anxiety {
  background: var(--bg-surface-subtle);
  border: 1px solid var(--border-subtle);
  color: var(--text-secondary);
}

.zone-flow {
  background: var(--color-primary-soft);
  border: 1px solid var(--color-primary);
  color: var(--text-accent);
  font-weight: 600;
}

.zone-boredom {
  background: var(--bg-surface-subtle);
  border: 1px solid var(--border-subtle);
  color: var(--text-secondary);
}

/* Takeaway Box */
.design-takeaway-box {
  background: var(--color-warning-soft);
  border: 1px solid rgba(245, 158, 11, 0.2);
  border-radius: var(--radius-md);
  padding: 18px 22px;
  margin-bottom: 36px;
  display: flex;
  align-items: flex-start;
  gap: 14px;
}

.takeaway-bulb {
  font-size: 1.3rem;
  flex-shrink: 0;
  line-height: 1.2;
}

.takeaway-body h4 {
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.8px;
  color: var(--color-warning);
  font-weight: 700;
  margin-bottom: 4px;
}

.takeaway-body p {
  font-size: 0.92rem;
  color: var(--text-primary);
  line-height: 1.55;
}

/* Checklist Section */
.checklist-section {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 28px 32px;
  box-shadow: var(--shadow-subtle);
}

.checklist-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--border-subtle);
}

.checklist-title-group h3 {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-primary);
}

.checklist-title-group p {
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.checklist-score {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text-accent);
  background: var(--bg-surface-elevated);
  padding: 5px 12px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-subtle);
}

.checklist-items {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.checklist-card {
  background: var(--bg-surface-subtle);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 16px 18px;
  transition: var(--transition);
}

.checklist-card:hover {
  border-color: var(--border-strong);
}

.checklist-card.checked {
  background: var(--color-success-soft);
  border-color: rgba(16, 185, 129, 0.3);
}

.checklist-row {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  cursor: pointer;
}

.custom-checkbox {
  width: 20px;
  height: 20px;
  border-radius: 4px;
  border: 1.5px solid var(--text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  margin-top: 2px;
  background: var(--bg-surface);
  transition: var(--transition);
}

.checklist-card.checked .custom-checkbox {
  background: var(--color-success);
  border-color: var(--color-success);
}

.checkbox-check-icon {
  display: none;
  color: #ffffff;
  font-size: 12px;
  font-weight: 800;
}

.checklist-card.checked .checkbox-check-icon {
  display: block;
}

.checklist-content {
  flex: 1;
}

.checklist-question {
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 6px;
}

.checklist-explanation {
  font-size: 0.84rem;
  color: var(--text-secondary);
  background: var(--bg-surface);
  padding: 10px 14px;
  border-radius: var(--radius-sm);
  margin-top: 6px;
  border-left: 2px solid var(--color-success);
  line-height: 1.5;
}

/* Minimal Bottom Bar */
.bottom-controls {
  position: sticky;
  bottom: 0;
  z-index: 100;
  background: var(--bg-surface);
  border-top: 1px solid var(--border-subtle);
  padding: 12px 32px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  box-shadow: var(--shadow-subtle);
}

.nav-shortcuts-hint {
  font-size: 0.75rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

.nav-shortcuts-hint kbd {
  background: var(--bg-surface-elevated);
  padding: 2px 5px;
  border-radius: 3px;
  border: 1px solid var(--border-subtle);
  color: var(--text-secondary);
}

.slide-nav-buttons {
  display: flex;
  align-items: center;
  gap: 10px;
}

.btn-nav {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  color: var(--text-primary);
  padding: 8px 18px;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 0.85rem;
  display: flex;
  align-items: center;
  gap: 6px;
  cursor: pointer;
  transition: var(--transition);
}

.btn-nav:hover:not(:disabled) {
  background: var(--bg-surface-elevated);
  border-color: var(--border-strong);
}

.btn-nav:disabled {
  opacity: 0.35;
  cursor: not-allowed;
}

.btn-nav.btn-primary-action {
  background: var(--color-primary);
  color: #ffffff;
  border-color: var(--color-primary);
}

.btn-nav.btn-primary-action:hover:not(:disabled) {
  background: #4338ca;
}

.progress-dots {
  display: flex;
  align-items: center;
  gap: 6px;
}

.dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--border-strong);
  cursor: pointer;
  transition: var(--transition);
}

.dot:hover {
  background: var(--text-secondary);
}

.dot.active {
  background: var(--color-primary);
  width: 18px;
  border-radius: 4px;
}

.dot.completed {
  background: var(--color-success);
}

/* Modals */
.modal-overlay {
  position: fixed;
  inset: 0;
  z-index: 200;
  background: rgba(0, 0, 0, 0.65);
  backdrop-filter: blur(4px);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s ease;
}

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

.modal-container {
  width: 100%;
  max-width: 920px;
  max-height: 85vh;
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  box-shadow: var(--shadow-card);
}

.modal-header {
  padding: 18px 24px;
  border-bottom: 1px solid var(--border-subtle);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.modal-header h2 {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-primary);
}

.btn-close {
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 1.3rem;
  cursor: pointer;
  padding: 2px 6px;
}

.btn-close:hover {
  color: var(--text-primary);
}

.modal-body {
  padding: 20px 24px;
  overflow-y: auto;
  flex: 1;
}

.chapters-grid-modal {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 12px;
}

.chapter-thumb-card {
  background: var(--bg-surface-subtle);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 14px 16px;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 8px;
}

.chapter-thumb-card:hover {
  background: var(--bg-surface-elevated);
  border-color: var(--border-strong);
}

.chapter-thumb-card.active-slide {
  border-color: var(--color-primary);
  background: var(--color-primary-soft);
}

.thumb-tag {
  font-size: 0.68rem;
  font-weight: 700;
  color: var(--text-accent);
  text-transform: uppercase;
}

.thumb-title {
  font-size: 0.88rem;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.35;
}

.thumb-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.72rem;
  color: var(--text-muted);
  border-top: 1px solid var(--border-subtle);
  padding-top: 6px;
}

.thumb-badge.done {
  color: var(--color-success);
  font-weight: 600;
}

/* Certificate Modal */
.cert-box {
  text-align: center;
  padding: 28px 16px;
}

.cert-icon {
  font-size: 3rem;
  margin-bottom: 12px;
}

.cert-box h3 {
  font-size: 1.5rem;
  font-weight: 800;
  margin-bottom: 8px;
  color: var(--text-primary);
}

.cert-box p {
  color: var(--text-secondary);
  font-size: 0.92rem;
  max-width: 540px;
  margin: 0 auto 20px;
}

.cert-stats-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
  max-width: 500px;
  margin: 0 auto 24px;
}

.cert-stat-card {
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-subtle);
  padding: 14px;
  border-radius: var(--radius-md);
}

.cert-stat-val {
  font-family: var(--font-mono);
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--text-primary);
}

.cert-stat-lbl {
  font-size: 0.72rem;
  color: var(--text-muted);
}

/* Reader Mode */
.reader-mode-container {
  display: flex;
  flex-direction: column;
  gap: 32px;
  max-width: 820px;
  margin: 0 auto;
  padding: 20px 0 60px;
}

/* Mobile */
@media (max-width: 768px) {
  .top-navbar {
    padding: 10px 16px;
  }
  .brand-info p {
    display: none;
  }
  .global-progress-bar-wrapper {
    display: none;
  }
  .slide-stage {
    padding: 16px 12px 30px;
  }
  .slide-card {
    padding: 24px 18px;
  }
  .flow-container {
    flex-direction: column;
  }
  .flow-arrow {
    transform: rotate(90deg);
  }
  .comparison-item {
    grid-template-columns: 1fr;
  }
  .comp-cat {
    border-right: none;
    border-bottom: 1px solid var(--border-subtle);
  }
  .bottom-controls {
    padding: 10px 16px;
  }
  .nav-shortcuts-hint {
    display: none;
  }
}