/* Global Styles */
:root {
  --primary-color: #4f46e5;
  --primary-hover: #4338ca;
  --secondary-color: #10b981;
  --background-color: #f8fafc;
  --card-background: #ffffff;
  --text-color: #1e293b;
  --text-muted: #64748b;
  --border-color: #e2e8f0;
  --error-color: #ef4444;
  --success-color: #10b981;
  --warning-color: #f59e0b;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
}

/* Reset and Base Styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html, body {
  height: 100%;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
  font-size: 16px;
  line-height: 1.5;
  color: var(--text-color);
  background-color: var(--background-color);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

/* Header */
.app-header {
  background: linear-gradient(135deg, var(--primary-color), #7c3aed);
  color: white;
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  box-shadow: var(--shadow-md);
}

.app-header a {
  color: white;
  text-decoration: none;
}

.app-title {
  font-size: 1.5rem;
  font-weight: 600;
}

.app-nav {
  display: flex;
  gap: 1.5rem;
}

.app-nav a {
  padding: 0.5rem 1rem;
  border-radius: var(--radius-md);
  transition: background-color 0.2s;
}

.app-nav a:hover {
  background-color: rgba(255, 255, 255, 0.1);
}

/* Main Content */
.app-main {
  flex: 1;
  padding: 2rem;
  max-width: 1400px;
  margin: 0 auto;
  width: 100%;
}

/* Footer */
.app-footer {
  text-align: center;
  padding: 1rem;
  color: var(--text-muted);
  font-size: 0.875rem;
  border-top: 1px solid var(--border-color);
}

/* Home Page */
.home-page {
  text-align: center;
  padding: 4rem 2rem;
}

.home-page h1 {
  font-size: 2.5rem;
  color: var(--primary-color);
  margin-bottom: 1rem;
}

.home-page p {
  color: var(--text-muted);
  margin-bottom: 2rem;
}

.nav-links {
  display: flex;
  justify-content: center;
  gap: 1rem;
  flex-wrap: wrap;
}

.nav-links a {
  display: block;
  padding: 0.75rem 1.5rem;
  background-color: var(--primary-color);
  color: white;
  border-radius: var(--radius-md);
  text-decoration: none;
  font-weight: 500;
  transition: all 0.2s;
}

.nav-links a:hover {
  background-color: var(--primary-hover);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

/* Not Found Page */
.not-found-page {
  text-align: center;
  padding: 4rem 2rem;
}

.not-found-page h1 {
  font-size: 4rem;
  color: var(--error-color);
  margin-bottom: 1rem;
}

.not-found-page a {
  display: inline-block;
  margin-top: 2rem;
  padding: 0.75rem 1.5rem;
  background-color: var(--primary-color);
  color: white;
  border-radius: var(--radius-md);
  text-decoration: none;
}

/* Story Page */
.story-page {
  max-width: 1400px;
  margin: 0 auto;
}

.page-header {
  margin-bottom: 2rem;
}

.page-header h1 {
  font-size: 2rem;
  color: var(--primary-color);
  margin-bottom: 0.5rem;
}

.level-description {
  color: var(--text-muted);
}

.level-selector {
  margin-bottom: 1rem;
}

.level-selector select {
  padding: 0.75rem 1rem;
  border: 2px solid var(--border-color);
  border-radius: var(--radius-md);
  font-size: 1rem;
  background-color: white;
  cursor: pointer;
  width: 100%;
  max-width: 400px;
}

.level-selector select:focus {
  outline: none;
  border-color: var(--primary-color);
}

/* Story Layout */
.story-layout {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 2rem;
  margin-top: 1rem;
}

/* Sidebar */
.story-sidebar {
  background-color: var(--card-background);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  box-shadow: var(--shadow-md);
  height: fit-content;
}

/* Story Main */
.story-main {
  background-color: var(--card-background);
  border-radius: var(--radius-lg);
  padding: 2rem;
  box-shadow: var(--shadow-md);
}

.story-content-wrapper {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

/* Segment Navigation */
.segment-navigation {
  display: flex;
  justify-content: space-between;
  padding: 1rem 0;
  border-bottom: 1px solid var(--border-color);
  margin-bottom: 1rem;
}

.nav-btn {
  padding: 0.5rem 1rem;
  background-color: var(--primary-color);
  color: white;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  font-size: 0.875rem;
  font-weight: 500;
  transition: all 0.2s;
}

.nav-btn:hover:not(:disabled) {
  background-color: var(--primary-hover);
}

.nav-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* Story Card */
.story-card {
  background-color: white;
  border-radius: var(--radius-lg);
  padding: 2rem;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border-color);
}

/* Story Segment */
.story-segment {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.segment-header {
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
}

.segment-title {
  font-size: 1.5rem;
  color: var(--primary-color);
  font-weight: 600;
}

.segment-theme {
  background-color: var(--primary-color);
  color: white;
  padding: 0.25rem 0.75rem;
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  font-weight: 500;
}

.segment-order {
  color: var(--text-muted);
  font-size: 0.875rem;
}

.segment-meta {
  display: flex;
  align-items: center;
  gap: 1rem;
  font-size: 0.875rem;
  color: var(--text-muted);
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border-color);
}

.completed-badge {
  background-color: var(--success-color);
  color: white;
  padding: 0.25rem 0.5rem;
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
}

.segment-body {
  line-height: 1.8;
  font-size: 1.125rem;
}

.story-content {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.story-paragraph {
  margin: 0;
}

.story-word {
  color: var(--primary-color);
  cursor: pointer;
  transition: all 0.1s;
  position: relative;
  display: inline;
}

.story-word:hover {
  color: var(--primary-hover);
  transform: scale(1.02);
}

.punctuation {
  display: inline;
}

.whitespace {
  display: inline;
}

.locked-content {
  color: var(--text-muted);
  font-style: italic;
  text-align: center;
  padding: 2rem;
}

.mark-complete-btn {
  padding: 0.75rem 1.5rem;
  background-color: var(--secondary-color);
  color: white;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  font-size: 1rem;
  font-weight: 500;
  transition: all 0.2s;
  align-self: flex-start;
}

.mark-complete-btn:hover {
  background-color: #059669;
  transform: translateY(-2px);
}

/* Audio Section */
.audio-section {
  margin-top: 2rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border-color);
}

.audio-section h4 {
  color: var(--primary-color);
  margin-bottom: 1rem;
}

/* Story Player */
.story-player {
  background-color: var(--card-background);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border-color);
}

.player-controls {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 1.5rem;
  margin-bottom: 1rem;
}

.player-btn {
  background-color: var(--primary-color);
  color: white;
  border: none;
  border-radius: 50%;
  width: 48px;
  height: 48px;
  cursor: pointer;
  font-size: 1.25rem;
  transition: all 0.2s;
  display: flex;
  align-items: center;
  justify-content: center;
}

.player-btn:hover:not(:disabled) {
  background-color: var(--primary-hover);
  transform: scale(1.05);
}

.player-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.play-pause-btn {
  width: 64px;
  height: 64px;
  font-size: 1.5rem;
}

.player-progress {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1rem;
}

.player-time {
  font-size: 0.75rem;
  color: var(--text-muted);
  min-width: 40px;
}

.seek-slider, .volume-slider {
  flex: 1;
  -webkit-appearance: none;
  height: 4px;
  background-color: var(--border-color);
  border-radius: 2px;
  outline: none;
}

.seek-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 16px;
  height: 16px;
  background-color: var(--primary-color);
  border-radius: 50%;
  cursor: pointer;
}

.seek-slider::-moz-range-thumb {
  width: 16px;
  height: 16px;
  background-color: var(--primary-color);
  border-radius: 50%;
  cursor: pointer;
  border: none;
}

.player-volume {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.volume-icon {
  font-size: 1rem;
}

.no-audio-notice,
.player-error {
  text-align: center;
  padding: 1rem;
  color: var(--text-muted);
}

/* Translation Tooltip */
.translation-tooltip {
  position: fixed;
  z-index: 1000;
  background-color: #2d3748;
  color: white;
  padding: 10px 15px;
  border-radius: 8px;
  font-size: 14px;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
  max-width: 300px;
}

.translation-tooltip strong {
  display: block;
  font-size: 1.25rem;
  margin-bottom: 8px;
  color: #fbbf24;
}

.translation-tooltip em {
  color: #a0aec0;
  font-size: 0.875rem;
}

/* Story Tab */
.story-tab {
  background-color: var(--card-background);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border-color);
}

.tab-header {
  margin-bottom: 1.5rem;
}

.tab-header h3 {
  color: var(--primary-color);
  margin-bottom: 1rem;
  font-size: 1.125rem;
}

.progress-summary {
  margin-bottom: 1rem;
}

.progress-count {
  display: block;
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-bottom: 0.5rem;
}

.progress-bar {
  height: 6px;
  background-color: var(--border-color);
  border-radius: 3px;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
  border-radius: 3px;
  transition: width 0.3s ease;
}

.segments-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.75rem;
}

.segment-card {
  padding: 1rem;
  border: 2px solid var(--border-color);
  border-radius: var(--radius-md);
  background-color: white;
  cursor: pointer;
  transition: all 0.2s;
  text-align: left;
  display: flex;
  flex-direction: column;
}

.segment-card:hover:not(:disabled) {
  border-color: var(--primary-color);
  box-shadow: var(--shadow-sm);
  transform: translateY(-2px);
}

.segment-card:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.segment-card.current {
  border-color: var(--primary-color);
  background-color: rgba(79, 70, 229, 0.05);
}

.segment-card.completed {
  border-color: var(--success-color);
  background-color: rgba(16, 185, 129, 0.1);
}

.segment-card.locked {
  opacity: 0.5;
  cursor: not-allowed;
}

.segment-card-content {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.segment-order {
  background-color: var(--primary-color);
  color: white;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  font-weight: 600;
  flex-shrink: 0;
}

.segment-title {
  flex: 1;
  font-size: 0.875rem;
  font-weight: 500;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.segment-status {
  font-size: 1rem;
}

/* Loading Indicators */
.loading-indicator {
  text-align: center;
  padding: 4rem 2rem;
  color: var(--text-muted);
}

.loading-indicator::after {
  content: '';
  animation: dots 1.5s steps(4, end) infinite;
}

@keyframes dots {
  0%, 20% { content: '.'; }
  40% { content: '..'; }
  60%, 100% { content: '...'; }
}

/* Error Messages */
.error-message {
  text-align: center;
  padding: 2rem;
  color: var(--error-color);
}

.error-message button,
.no-story-notice button {
  margin-top: 1rem;
  padding: 0.5rem 1rem;
  background-color: var(--primary-color);
  color: white;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
}

/* No Story Notice */
.no-story-notice {
  text-align: center;
  padding: 2rem;
  color: var(--text-muted);
}

/* Responsive Design */
@media (max-width: 768px) {
  .story-layout {
    grid-template-columns: 1fr;
  }

  .story-sidebar {
    order: 2;
  }

  .story-main {
    order: 1;
  }

  .segments-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .page-header h1 {
    font-size: 1.5rem;
  }

  .level-selector select {
    max-width: 100%;
  }
}

@media (max-width: 480px) {
  .app-header {
    flex-direction: column;
    gap: 1rem;
    padding: 1rem;
  }

  .app-nav {
    flex-wrap: wrap;
    justify-content: center;
    gap: 1rem;
  }

  .story-layout {
    gap: 1rem;
  }

  .story-main {
    padding: 1rem;
  }

  .story-card {
    padding: 1rem;
  }

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

  .player-controls {
    gap: 1rem;
  }

  .player-btn.play-pause-btn {
    width: 56px;
    height: 56px;
    font-size: 1.25rem;
  }
}