/* Mụta Igbo CSS stylesheet */

/* 1. Reset and Fonts */
@import url('https://fonts.googleapis.com/css2?family=Outfit:wght@300;400;500;600;700&family=Playfair+Display:ital,wght@0,500;0,700;1,400&display=swap');

:root {
  /* Colors */
  --bg-color: #0c0f17;
  --bg-gradient: linear-gradient(135deg, #0c0f17 0%, #151a2d 100%);
  --panel-bg: rgba(22, 28, 45, 0.7);
  --panel-border: rgba(255, 255, 255, 0.08);
  --panel-border-glow: rgba(212, 175, 55, 0.25);
  
  --primary: #0f5132;         /* Deep Forest Green */
  --primary-light: #198754;   /* Vibrant Green */
  --accent: #d4af37;          /* Rich African Gold */
  --accent-light: #ffc107;    /* Bright Gold */
  --terracotta: #d45d3b;      /* Warm Terracotta */
  --error: #dc3545;
  --success: #198754;
  
  --text-main: #f8f9fa;       /* Cream White */
  --text-muted: #a0aec0;      /* Slate Gray */
  --text-dark: #0f172a;
  
  /* Layout Metrics */
  --border-radius-sm: 8px;
  --border-radius-md: 16px;
  --border-radius-lg: 24px;
  --transition-smooth: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --shadow-premium: 0 10px 30px -10px rgba(0, 0, 0, 0.5);
  --shadow-glow: 0 0 20px rgba(212, 175, 55, 0.15);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  scrollbar-width: thin;
  scrollbar-color: var(--accent) var(--bg-color);
}

body {
  font-family: 'Outfit', sans-serif;
  background: var(--bg-gradient);
  color: var(--text-main);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
}

/* 2. Global Typography */
h1, h2, h3, h4, .font-serif {
  font-family: 'Playfair Display', serif;
  font-weight: 700;
  letter-spacing: -0.02em;
}

p {
  line-height: 1.6;
  color: var(--text-muted);
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: var(--transition-smooth);
}

a:hover {
  color: var(--accent-light);
}

/* 3. Layout Structure */
header {
  background: rgba(12, 15, 23, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--panel-border);
  position: sticky;
  top: 0;
  z-index: 100;
  padding: 1rem 2rem;
}

.header-container {
  max-width: 1400px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.brand-logo {
  font-size: 2.2rem;
  background: linear-gradient(135deg, var(--accent) 0%, var(--terracotta) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  font-weight: 700;
}

.brand-subtitle {
  font-size: 0.8rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

/* Navigation Menu */
nav ul {
  display: flex;
  list-style: none;
  gap: 1.5rem;
}

nav a {
  font-weight: 500;
  padding: 0.5rem 1rem;
  border-radius: var(--border-radius-sm);
  color: var(--text-muted);
}

nav a.active, nav a:hover {
  color: var(--text-main);
  background: rgba(255, 255, 255, 0.05);
  border-bottom: 2px solid var(--accent);
  border-radius: 4px 4px 0 0;
}

/* Header controls wrapper */
.header-controls {
  display: flex;
  align-items: center;
  gap: 1rem;
}

/* Audio Pronunciation Settings Bar */
.audio-settings-bar {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  background: rgba(255, 255, 255, 0.03);
  padding: 0.5rem 1rem;
  border-radius: 50px;
  border: 1px solid var(--panel-border);
  transition: var(--transition-smooth);
}

.audio-settings-bar:hover {
  border-color: rgba(212, 175, 55, 0.3);
  background: rgba(255, 255, 255, 0.05);
}

#audio-mode-select {
  background: transparent;
  color: var(--text-main);
  border: none;
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  outline: none;
  font-family: 'Outfit', sans-serif;
}

#audio-mode-select option {
  background: var(--bg-color);
  color: var(--text-main);
}

/* User Progress Stats Header */
.user-stats-bar {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  background: rgba(255, 255, 255, 0.03);
  padding: 0.5rem 1.25rem;
  border-radius: 50px;
  border: 1px solid var(--panel-border);
}

.stat-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.9rem;
}

.stat-icon {
  font-size: 1.1rem;
}

.xp-pill {
  background: var(--primary);
  color: white;
  padding: 0.2rem 0.6rem;
  border-radius: 20px;
  font-size: 0.75rem;
  font-weight: 600;
}

/* Main Container */
main {
  flex: 1;
  max-width: 1400px;
  width: 100%;
  margin: 0 auto;
  padding: 2rem;
  position: relative;
}

/* View Sections visibility */
.view-section {
  display: none;
  animation: fadeIn 0.4s ease-out forwards;
}

.view-section.active-view {
  display: block;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

/* 4. Glassmorphic Card Panel */
.glass-panel {
  background: var(--panel-bg);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--panel-border);
  border-radius: var(--border-radius-md);
  padding: 2rem;
  box-shadow: var(--shadow-premium);
  margin-bottom: 2rem;
  position: relative;
  overflow: hidden;
}

.glass-panel::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--primary) 0%, var(--accent) 50%, var(--terracotta) 100%);
}

.panel-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.5rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
  padding-bottom: 0.75rem;
}

.panel-header h2 {
  font-size: 1.8rem;
  color: var(--accent);
}

/* 5. DASHBOARD VIEW DESIGN */
.welcome-hero {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 2rem;
  margin-bottom: 2.5rem;
}

.hero-text-block {
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.hero-text-block h1 {
  font-size: 3rem;
  line-height: 1.1;
  margin-bottom: 1rem;
}

.hero-text-block h1 span {
  color: var(--accent);
}

.hero-stats-card {
  background: radial-gradient(circle at top right, rgba(212, 175, 55, 0.15), transparent);
  border: 1px solid var(--panel-border-glow);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding: 2rem;
}

.streak-counter {
  font-size: 3rem;
  font-weight: 700;
  color: var(--accent-light);
  display: flex;
  align-items: center;
  gap: 0.5rem;
  line-height: 1;
}

.progress-container {
  margin-top: 1rem;
}

.progress-info {
  display: flex;
  justify-content: space-between;
  margin-bottom: 0.5rem;
  font-size: 0.85rem;
}

.progress-bar-bg {
  width: 100%;
  height: 8px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 10px;
  overflow: hidden;
}

.progress-bar-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--primary-light), var(--accent));
  width: 0%;
  transition: width 0.8s cubic-bezier(0.1, 0.8, 0.2, 1);
}

/* Dashboard Sections Grid */
.dashboard-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
}

.learning-pathway {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.level-card {
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid rgba(255, 255, 255, 0.05);
  border-radius: var(--border-radius-md);
  padding: 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  transition: var(--transition-smooth);
}

.level-card:hover {
  background: rgba(255, 255, 255, 0.05);
  transform: translateX(5px);
  border-color: rgba(212, 175, 55, 0.3);
}

.level-info {
  flex: 1;
}

.level-badge {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.25rem;
  letter-spacing: 0.05em;
}

.level-card h3 {
  font-size: 1.3rem;
  margin-bottom: 0.25rem;
  color: var(--text-main);
}

.level-card p {
  font-size: 0.9rem;
}

.level-action-btn {
  background: var(--primary);
  border: none;
  color: white;
  padding: 0.75rem 1.25rem;
  border-radius: var(--border-radius-sm);
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition-smooth);
}

.level-action-btn:hover {
  background: var(--primary-light);
  box-shadow: 0 0 10px rgba(25, 135, 84, 0.4);
}

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

.level-card.locked:hover {
  transform: none;
  border-color: rgba(255, 255, 255, 0.05);
}

.level-card.locked .level-action-btn {
  background: #334155;
  cursor: not-allowed;
}

/* Vocab of the Day Card */
.daily-vocab-box {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  background: radial-gradient(circle at center, rgba(15, 81, 50, 0.15) 0%, transparent 100%);
  border: 1px dashed rgba(212, 175, 55, 0.3);
}

.vocab-of-day-content {
  text-align: center;
  padding: 1.5rem 0;
}

.vocab-of-day-word {
  font-size: 2.8rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 0.5rem;
  position: relative;
  display: inline-block;
}

.vocab-of-day-translation {
  font-size: 1.3rem;
  color: var(--accent);
  font-style: italic;
}

.vocab-of-day-phonetic {
  color: var(--text-muted);
  font-size: 1rem;
  margin-top: 0.25rem;
}

/* 6. ALPHABET VIEW DESIGN */
.alphabet-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(130px, 1fr));
  gap: 1.25rem;
}

.letter-card {
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid rgba(255, 255, 255, 0.05);
  border-radius: var(--border-radius-md);
  padding: 1.5rem 1rem;
  text-align: center;
  cursor: pointer;
  transition: var(--transition-smooth);
  position: relative;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  height: 160px;
}

.letter-card:hover {
  background: rgba(255, 255, 255, 0.06);
  transform: translateY(-5px);
  border-color: var(--accent);
  box-shadow: var(--shadow-glow);
}

.letter-char {
  font-size: 2.2rem;
  font-weight: 700;
  color: var(--text-main);
  line-height: 1;
}

.letter-name {
  color: var(--accent);
  font-size: 0.9rem;
  font-weight: 500;
}

.letter-example {
  font-size: 0.85rem;
  color: var(--text-muted);
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  padding-top: 0.5rem;
  margin-top: 0.5rem;
}

.letter-badge-vowel {
  position: absolute;
  top: 8px;
  right: 8px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--terracotta);
}

/* Alphabet Info overlay drawer */
.alphabet-detail-panel {
  display: none;
  margin-top: 2rem;
  background: rgba(15, 81, 50, 0.1);
  border: 1px solid rgba(25, 135, 84, 0.3);
  padding: 1.5rem;
  border-radius: var(--border-radius-md);
  animation: fadeIn 0.3s ease-out;
}

.alphabet-detail-grid {
  display: grid;
  grid-template-columns: 120px 1fr;
  gap: 1.5rem;
  align-items: center;
}

.alphabet-detail-char {
  font-size: 4rem;
  font-weight: 700;
  color: var(--accent-light);
  text-align: center;
  line-height: 1;
  background: rgba(0, 0, 0, 0.2);
  padding: 1.5rem;
  border-radius: var(--border-radius-md);
}

.alphabet-detail-info h3 {
  font-size: 1.5rem;
  margin-bottom: 0.5rem;
}

.audio-trigger-btn {
  background: rgba(212, 175, 55, 0.1);
  border: 1px solid var(--accent);
  color: var(--accent-light);
  padding: 0.4rem 0.8rem;
  border-radius: 20px;
  font-size: 0.85rem;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-weight: 500;
  transition: var(--transition-smooth);
}

.audio-trigger-btn:hover {
  background: var(--accent);
  color: var(--text-dark);
}

/* 7. LESSONS VIEW DESIGN */
.lessons-container {
  display: grid;
  grid-template-columns: 320px 1fr;
  gap: 2rem;
}

.lessons-sidebar {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.lesson-nav-group {
  margin-bottom: 1.5rem;
}

.lesson-group-title {
  font-size: 0.85rem;
  text-transform: uppercase;
  color: var(--accent);
  letter-spacing: 0.05em;
  margin-bottom: 0.5rem;
  font-weight: 600;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
  padding-bottom: 0.25rem;
}

.lesson-nav-list {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  list-style: none;
}

.lesson-nav-item {
  padding: 0.75rem 1rem;
  border-radius: var(--border-radius-sm);
  background: rgba(255, 255, 255, 0.01);
  border: 1px solid rgba(255, 255, 255, 0.03);
  cursor: pointer;
  font-size: 0.9rem;
  transition: var(--transition-smooth);
}

.lesson-nav-item:hover {
  background: rgba(255, 255, 255, 0.04);
  border-color: rgba(255, 255, 255, 0.1);
}

.lesson-nav-item.active {
  background: rgba(25, 135, 84, 0.15);
  border-color: var(--primary-light);
  color: var(--text-main);
  font-weight: 500;
}

.lesson-nav-item.locked {
  opacity: 0.4;
  cursor: not-allowed;
}

.lesson-nav-item.locked:hover {
  background: none;
  border-color: rgba(255, 255, 255, 0.03);
}

/* Lesson Display Area */
.lesson-body {
  animation: fadeIn 0.4s ease-out;
}

.lesson-article {
  margin-top: 1rem;
}

.lesson-article h3 {
  font-size: 1.5rem;
  margin: 1.5rem 0 0.75rem;
  color: var(--accent);
}

.lesson-article p {
  margin-bottom: 1rem;
  font-size: 1.05rem;
}

.lesson-article ul, .lesson-article ol {
  margin-left: 1.5rem;
  margin-bottom: 1.25rem;
  color: var(--text-muted);
}

.lesson-article li {
  margin-bottom: 0.5rem;
}

/* Lesson Custom Layout elements */
.harmony-table-container {
  overflow-x: auto;
  margin: 1.5rem 0;
}

.data-table {
  width: 100%;
  border-collapse: collapse;
  background: rgba(0, 0, 0, 0.2);
  border-radius: var(--border-radius-sm);
  overflow: hidden;
}

.data-table th, .data-table td {
  padding: 0.8rem 1.2rem;
  text-align: left;
}

.data-table th {
  background: rgba(255, 255, 255, 0.05);
  color: var(--accent);
  font-weight: 600;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.data-table td {
  border-bottom: 1px solid rgba(255, 255, 255, 0.03);
}

.heavy-row { border-left: 4px solid var(--terracotta); }
.light-row { border-left: 4px solid var(--accent); }

.warning-box {
  background: rgba(212, 93, 59, 0.1);
  border-left: 4px solid var(--terracotta);
  padding: 1.25rem;
  border-radius: 0 var(--border-radius-sm) var(--border-radius-sm) 0;
  margin: 1.5rem 0;
}

.warning-box strong {
  color: var(--text-main);
}

.tone-demo-box {
  background: rgba(0, 0, 0, 0.15);
  border: 1px solid rgba(255, 255, 255, 0.05);
  padding: 1.5rem;
  border-radius: var(--border-radius-md);
  margin: 1.5rem 0;
}

.word-card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 1rem;
  margin-top: 1rem;
}

.word-mini-card {
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid rgba(255, 255, 255, 0.05);
  padding: 1rem;
  border-radius: var(--border-radius-sm);
  text-align: center;
  display: flex;
  flex-direction: column;
  transition: var(--transition-smooth);
}

.word-mini-card:hover {
  background: rgba(255, 255, 255, 0.05);
  transform: scale(1.03);
}

.vocab-word {
  font-size: 1.6rem;
  font-weight: 600;
  color: var(--text-main);
}

.vocab-tone {
  font-size: 0.75rem;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin: 0.25rem 0;
}

.vocab-translation {
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* Lesson Vocabulary Practice Section */
.lesson-practice-header {
  font-size: 1.4rem;
  color: var(--accent-light);
  margin-top: 2rem;
  margin-bottom: 1rem;
}

.vocab-practice-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.5rem;
}

.vocab-practice-card {
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid rgba(255, 255, 255, 0.05);
  border-radius: var(--border-radius-md);
  padding: 1.25rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: var(--transition-smooth);
}

.vocab-practice-card:hover {
  background: rgba(255, 255, 255, 0.04);
  border-color: rgba(25, 135, 84, 0.3);
}

.card-vocab-word {
  font-size: 1.8rem;
  font-weight: 700;
}

.card-vocab-ph {
  font-size: 0.85rem;
  color: var(--text-muted);
  font-family: monospace;
}

.card-vocab-trans {
  font-size: 1rem;
  color: var(--accent);
  margin-top: 0.25rem;
}

.card-actions {
  display: flex;
  gap: 0.5rem;
}

.round-audio-btn {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.1);
  color: var(--text-main);
  font-size: 1rem;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: var(--transition-smooth);
}

.round-audio-btn:hover {
  background: var(--accent);
  color: var(--text-dark);
  border-color: var(--accent);
  transform: scale(1.1);
}

.round-audio-btn.tone-btn:hover {
  background: var(--terracotta);
  border-color: var(--terracotta);
}

/* Audio Syllable Animation triggers */
@keyframes voicePulse {
  0% { transform: scale(1); box-shadow: 0 0 0 0 rgba(212, 175, 55, 0.4); }
  70% { transform: scale(1.05); box-shadow: 0 0 0 8px rgba(212, 175, 55, 0); }
  100% { transform: scale(1); box-shadow: 0 0 0 0 rgba(212, 175, 55, 0); }
}

.audio-playing {
  animation: voicePulse 0.4s ease-out;
}

/* Syllable tone indicator dots overlay */
.syllable-indicator-row {
  display: flex;
  justify-content: center;
  gap: 0.5rem;
  margin-top: 0.5rem;
  min-height: 20px;
}

.syllable-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.15);
  transition: var(--transition-smooth);
}

.syllable-dot.active-syllable {
  background: var(--accent);
  box-shadow: 0 0 10px var(--accent-light);
  transform: scale(1.4);
}

/* 8. FLASHCARDS VOCABULARY DECK DESIGN */
.deck-selector-row {
  display: flex;
  gap: 1rem;
  margin-bottom: 2rem;
  overflow-x: auto;
  padding-bottom: 0.5rem;
}

.deck-tab {
  padding: 0.6rem 1.25rem;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid rgba(255, 255, 255, 0.05);
  color: var(--text-muted);
  border-radius: 30px;
  cursor: pointer;
  white-space: nowrap;
  font-weight: 500;
  transition: var(--transition-smooth);
}

.deck-tab:hover, .deck-tab.active {
  background: rgba(212, 175, 55, 0.1);
  color: var(--accent-light);
  border-color: var(--accent);
}

/* Flashcard Container and Flip System */
.flashcard-arena {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  max-width: 500px;
  margin: 0 auto;
}

.flashcard-perspective {
  perspective: 1000px;
  width: 100%;
  height: 300px;
  cursor: pointer;
  margin-bottom: 1.5rem;
}

.flashcard-inner {
  position: relative;
  width: 100%;
  height: 100%;
  text-align: center;
  transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
  transform-style: preserve-3d;
}

.flashcard-perspective.flipped .flashcard-inner {
  transform: rotateY(180deg);
}

.card-face {
  position: absolute;
  width: 100%;
  height: 100%;
  -webkit-backface-visibility: hidden; /* Safari */
  backface-visibility: hidden;
  border-radius: var(--border-radius-lg);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding: 2rem;
  box-shadow: var(--shadow-premium);
  border: 1px solid var(--panel-border);
}

/* Front Face (Igbo Word) */
.card-front {
  background: radial-gradient(circle at 10% 20%, rgba(22, 28, 45, 0.9) 0%, rgba(12, 15, 23, 0.95) 100%);
  color: var(--text-main);
  border-bottom: 4px solid var(--accent);
}

.card-back {
  background: radial-gradient(circle at 90% 80%, rgba(15, 81, 50, 0.15) 0%, rgba(22, 28, 45, 0.95) 100%);
  color: var(--text-main);
  transform: rotateY(180deg);
  border-bottom: 4px solid var(--primary-light);
}

.card-metadata {
  display: flex;
  justify-content: space-between;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.card-center-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  flex: 1;
}

.card-igbo-word {
  font-size: 3.5rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  letter-spacing: -0.01em;
}

.card-phonetics-label {
  font-size: 1rem;
  color: var(--text-muted);
  font-family: monospace;
}

.card-english-translation {
  font-size: 2.2rem;
  font-weight: 600;
  color: var(--accent);
  margin-bottom: 0.5rem;
}

.card-vocab-type {
  font-size: 0.85rem;
  background: rgba(255, 255, 255, 0.05);
  padding: 0.2rem 0.6rem;
  border-radius: 12px;
  color: var(--text-muted);
}

.card-flip-prompt {
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

/* Card Arena Control Buttons */
.card-nav-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  width: 100%;
  gap: 1rem;
}

.card-btn {
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--panel-border);
  color: var(--text-main);
  padding: 0.75rem 1.5rem;
  border-radius: var(--border-radius-sm);
  cursor: pointer;
  font-weight: 500;
  transition: var(--transition-smooth);
}

.card-btn:hover {
  background: rgba(255, 255, 255, 0.08);
}

.card-btn-accent {
  background: var(--primary);
  border-color: var(--primary-light);
}

.card-btn-accent:hover {
  background: var(--primary-light);
  box-shadow: 0 0 12px rgba(25, 135, 84, 0.3);
}

.card-counter-indicator {
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* 9. GREETINGS & SITUATIONAL DIALOGUE */
.greetings-accordion {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.greeting-category-block h3 {
  font-size: 1.4rem;
  color: var(--accent-light);
  margin-bottom: 0.75rem;
  border-left: 3px solid var(--accent);
  padding-left: 0.5rem;
}

.phrases-list-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(360px, 1fr));
  gap: 1.25rem;
}

.phrase-row-card {
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid rgba(255, 255, 255, 0.04);
  border-radius: var(--border-radius-md);
  padding: 1.25rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: var(--transition-smooth);
}

.phrase-row-card:hover {
  background: rgba(255, 255, 255, 0.04);
  border-color: rgba(212, 175, 55, 0.2);
  transform: translateY(-2px);
}

.phrase-text-group {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.phrase-igbo {
  font-size: 1.3rem;
  font-weight: 600;
  color: var(--text-main);
}

.phrase-english {
  font-size: 0.95rem;
  color: var(--accent);
}

.phrase-response {
  font-size: 0.85rem;
  color: var(--text-muted);
  font-style: italic;
}

.phrase-context {
  font-size: 0.75rem;
  background: rgba(255, 255, 255, 0.05);
  color: var(--text-muted);
  padding: 0.1rem 0.4rem;
  border-radius: 4px;
  align-self: flex-start;
  margin-top: 0.25rem;
}

/* 10. TONE TRAINER VIEW */
.tone-trainer-interactive {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
}

.tone-desc-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.tone-concept-card {
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid rgba(255, 255, 255, 0.05);
  border-radius: var(--border-radius-md);
  padding: 1.25rem;
  cursor: pointer;
  transition: var(--transition-smooth);
}

.tone-concept-card:hover {
  border-color: var(--accent);
  background: rgba(255, 255, 255, 0.04);
}

.tone-accent-mark {
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--accent-light);
  line-height: 1;
}

.tone-trainer-practice {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  border: 1px dashed rgba(255, 255, 255, 0.1);
  border-radius: var(--border-radius-md);
  padding: 2rem;
}

.tone-contour-canvas-container {
  width: 100%;
  height: 120px;
  background: rgba(0, 0, 0, 0.2);
  border-radius: var(--border-radius-sm);
  margin-top: 1.5rem;
  position: relative;
  display: flex;
  justify-content: space-around;
  align-items: center;
  padding: 0 2rem;
}

.tone-contour-node {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: #334155;
  border: 2px solid #475569;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.8rem;
  color: white;
  transition: all 0.3s cubic-bezier(0.1, 0.8, 0.2, 1);
  position: relative;
  --y-translate: -5px;
  transform: translateY(var(--y-translate)) scale(1);
}

.tone-contour-node.active-pitch {
  background: var(--accent);
  border-color: var(--accent-light);
  box-shadow: 0 0 15px var(--accent);
  transform: translateY(var(--y-translate)) scale(1.25);
}

.tone-contour-node.pitch-high { --y-translate: -25px; }
.tone-contour-node.pitch-low { --y-translate: 25px; }
.tone-contour-node.pitch-down { --y-translate: -5px; }

/* SVG Connection line for visual flow */
.tone-contour-line {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 0;
}

/* 11. DYNAMIC QUIZZES DESIGN */
.quiz-welcome-screen {
  text-align: center;
  max-width: 600px;
  margin: 3rem auto;
}

.start-quiz-btn {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
  border: none;
  color: white;
  font-size: 1.2rem;
  font-weight: 600;
  padding: 1rem 2.5rem;
  border-radius: 30px;
  cursor: pointer;
  margin-top: 1.5rem;
  box-shadow: 0 5px 15px rgba(25, 135, 84, 0.3);
  transition: var(--transition-smooth);
}

.start-quiz-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(25, 135, 84, 0.5);
}

.quiz-container {
  max-width: 800px;
  margin: 0 auto;
}

.quiz-progress-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.5rem;
  font-size: 0.9rem;
}

.quiz-score-indicator {
  font-weight: 600;
  color: var(--accent);
}

.quiz-question-box {
  margin-bottom: 2rem;
}

.quiz-question-text {
  font-size: 1.4rem;
  margin-bottom: 1.5rem;
  color: var(--text-main);
  line-height: 1.4;
}

.quiz-options-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.quiz-option-btn {
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid rgba(255, 255, 255, 0.06);
  padding: 1rem 1.5rem;
  border-radius: var(--border-radius-md);
  text-align: left;
  font-size: 1rem;
  color: var(--text-main);
  cursor: pointer;
  transition: var(--transition-smooth);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.quiz-option-btn:hover:not(.checked) {
  background: rgba(255, 255, 255, 0.05);
  border-color: rgba(255, 255, 255, 0.2);
  transform: translateX(4px);
}

.quiz-option-btn.correct-option {
  background: rgba(25, 135, 84, 0.2) !important;
  border-color: var(--success) !important;
  color: #a3e635;
}

.quiz-option-btn.incorrect-option {
  background: rgba(220, 53, 69, 0.2) !important;
  border-color: var(--error) !important;
  color: #fda4af;
}

.quiz-option-btn.checked {
  pointer-events: none;
}

.quiz-explanation-box {
  display: none;
  background: rgba(255, 255, 255, 0.03);
  border-left: 3px solid var(--accent);
  padding: 1.25rem;
  border-radius: 0 var(--border-radius-sm) var(--border-radius-sm) 0;
  margin-top: 1.5rem;
  animation: fadeIn 0.3s ease-out;
}

.quiz-explanation-box h5 {
  color: var(--accent);
  margin-bottom: 0.25rem;
  font-size: 0.95rem;
}

.quiz-explanation-text {
  font-size: 0.9rem;
  color: var(--text-muted);
}

.quiz-footer {
  display: flex;
  justify-content: flex-end;
  margin-top: 2rem;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  padding-top: 1rem;
}

.quiz-next-btn {
  background: var(--accent);
  color: var(--text-dark);
  border: none;
  padding: 0.75rem 2rem;
  border-radius: var(--border-radius-sm);
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition-smooth);
}

.quiz-next-btn:hover {
  background: var(--accent-light);
  transform: translateY(-1px);
}

/* Quiz Finished Panel */
.quiz-finished-card {
  text-align: center;
  padding: 3rem 2rem;
}

.quiz-finished-icon {
  font-size: 4rem;
  color: var(--accent-light);
  margin-bottom: 1rem;
  animation: bounce 1s infinite alternate;
}

@keyframes bounce {
  from { transform: translateY(0); }
  to { transform: translateY(-10px); }
}

.quiz-results-score {
  font-size: 2.2rem;
  font-weight: 700;
  margin-bottom: 1rem;
}

.quiz-xp-earned {
  color: var(--success);
  font-size: 1.2rem;
  font-weight: 600;
  margin-bottom: 1.5rem;
}

.quiz-finish-actions {
  display: flex;
  justify-content: center;
  gap: 1rem;
}

/* 12. PROVERBS VIEW DESIGN */
.proverbs-header-desc {
  margin-bottom: 2rem;
  max-width: 800px;
}

.proverbs-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(400px, 1fr));
  gap: 1.5rem;
}

.proverbs-grid .glass-panel {
  margin-bottom: 0;
  height: 100%;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.proverb-card-text {
  font-size: 1.4rem;
  font-weight: 600;
  color: var(--text-main);
  margin-bottom: 0.5rem;
  line-height: 1.4;
}

.proverb-literal {
  font-size: 0.95rem;
  color: var(--accent);
  font-style: italic;
  margin-bottom: 1rem;
  border-bottom: 1px dashed rgba(255, 255, 255, 0.05);
  padding-bottom: 0.75rem;
}

.proverb-deeper {
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.5;
}

/* 13. Footer Design */
footer {
  margin-top: auto;
  border-top: 1px solid var(--panel-border);
  background: rgba(12, 15, 23, 0.9);
  padding: 2rem;
  text-align: center;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.footer-content {
  max-width: 1400px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

/* Mobile elements hidden on desktop */
.mobile-nav-toggle {
  display: none;
}
.drawer-audio-settings {
  display: none;
}

/* Responsive Adaptations */
@media (max-width: 1300px) {
  .header-container {
    flex-wrap: nowrap;
    gap: 1rem;
    justify-content: space-between;
  }
}

@media (max-width: 992px) {
  /* Welcome Hero scaling */
  .welcome-hero {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }
  .hero-text-block h1 {
    font-size: 2rem !important;
    text-align: center;
  }
  .hero-text-block p {
    text-align: center;
    margin-bottom: 1.5rem;
  }
  .hero-stats-card {
    padding: 1.5rem;
  }

  /* Hamburger Menu Toggle Button */
  .mobile-nav-toggle {
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    width: 26px;
    height: 18px;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 0;
    z-index: 1100;
  }
  .hamburger-bar {
    width: 100%;
    height: 3px;
    background-color: var(--text-main);
    border-radius: 4px;
    transition: var(--transition-smooth);
  }
  .mobile-nav-toggle.active .hamburger-bar:nth-child(1) {
    transform: translateY(7.5px) rotate(45deg);
    background-color: var(--accent);
  }
  .mobile-nav-toggle.active .hamburger-bar:nth-child(2) {
    opacity: 0;
  }
  .mobile-nav-toggle.active .hamburger-bar:nth-child(3) {
    transform: translateY(-7.5px) rotate(-45deg);
    background-color: var(--accent);
  }

  /* Slide-Down Mobile Navigation Overlay Drawer */
  nav {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    background: var(--bg-color);
    z-index: 1000;
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
    align-items: center;
    padding: 6rem 1.5rem 3rem 1.5rem;
    overflow-y: auto;
    transform: translateY(-100%);
    transition: transform 0.4s cubic-bezier(0.1, 0.8, 0.2, 1);
    opacity: 0;
    visibility: hidden;
  }
  nav.active {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }
  nav ul {
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
    width: 100%;
  }
  nav a {
    font-size: 1.3rem;
    color: var(--text-muted);
    padding: 0.5rem 2rem;
    display: block;
    width: 80%;
    text-align: center;
    border-bottom: none !important;
  }
  nav a.active, nav a:hover {
    background: rgba(255, 255, 255, 0.05);
    border-radius: var(--border-radius-sm);
    color: var(--accent-light);
  }

  /* Audio Settings layout swap on Mobile */
  .header-audio-settings {
    display: none !important;
  }
  .drawer-audio-settings {
    display: block;
    margin-top: 2.5rem;
    width: 80%;
    max-width: 280px;
    text-align: center;
  }
  .drawer-audio-settings .audio-settings-bar {
    justify-content: center;
  }

  /* Grid Stack layouts */
  .dashboard-grid {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }
  .lessons-container {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }
  .lessons-sidebar {
    flex-direction: row;
    overflow-x: auto;
    padding: 0.75rem;
    gap: 1rem;
    white-space: nowrap;
    border-bottom: 1px solid var(--panel-border);
    -webkit-overflow-scrolling: touch;
  }
  .lesson-nav-group {
    display: inline-block;
    vertical-align: top;
    margin-bottom: 0;
    margin-right: 1.5rem;
    flex-shrink: 0;
  }
  .lesson-nav-list {
    flex-direction: row;
    gap: 0.5rem;
  }
  .lesson-nav-item {
    white-space: nowrap;
  }
  .tone-trainer-interactive {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
}

@media (max-width: 768px) {
  .header-container {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
    gap: 0.5rem;
    padding: 0.25rem 0.5rem;
  }
  main {
    padding: 1rem 0.75rem;
  }
  .glass-panel {
    padding: 1.25rem;
  }
  .footer-content {
    flex-direction: column;
    gap: 1rem;
    text-align: center;
  }
  
  /* Prevent horizontal grid overflows */
  .proverbs-grid {
    grid-template-columns: 1fr;
  }
  .phrases-list-grid {
    grid-template-columns: 1fr;
    gap: 1rem;
  }
  .vocab-practice-grid {
    grid-template-columns: 1fr;
    gap: 1rem;
  }
  .word-card-grid {
    grid-template-columns: 1fr;
  }

  /* Alphabet Detail Panel stacking */
  .alphabet-detail-grid {
    grid-template-columns: 1fr;
    text-align: center;
    gap: 1rem;
  }
  .alphabet-detail-char {
    margin: 0 auto;
    font-size: 3rem;
    width: 80px;
    height: 80px;
    padding: 0;
    display: flex;
    align-items: center;
    justify-content: center;
  }
  .alphabet-detail-info div {
    flex-direction: column;
    gap: 1rem;
    align-items: center;
  }
}

@media (max-width: 580px) {
  /* Simplify User Stats Bar on narrow screens to fit nicely */
  .user-stats-bar {
    gap: 0.5rem;
    padding: 0.35rem 0.75rem;
  }
  .stat-item {
    font-size: 0.8rem;
  }
  /* Hide Level Badge on very small viewports */
  .stat-item:nth-child(3) {
    display: none;
  }
  .brand-logo {
    font-size: 1.6rem;
  }
  .brand-subtitle {
    display: none;
  }
}