:root {
  --primary-blue: #003399;
  --header-bg: #003893;
  --accent-crimson: #c8102e;
  --bg-color: #f4f6f8;
  --card-bg: #ffffff;
  --text-dark: #1a1a1a;
  --text-muted: #555555;
  --border-color: #e0e0e0;
  --radius-lg: 12px;
  --radius-md: 8px;
  --radius-sm: 6px;
  --font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-deva: "Noto Sans Devanagari", sans-serif;
}

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

body {
  font-family: var(--font-family);
  background-color: var(--bg-color);
  color: var(--text-dark);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
}

/* Header / Banner Styling */
.topbar {
  width: 100%;
  background-color: var(--header-bg);
  color: #ffffff;
  padding: 32px 10%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
}

.brand {
  font-size: 1.8rem;
  font-weight: 700;
  letter-spacing: 0.5px;
}

.sound-toggle {
  background: rgba(255, 255, 255, 0.15);
  border: 1px solid rgba(255, 255, 255, 0.3);
  color: #ffffff;
  border-radius: 50%;
  width: 44px;
  height: 44px;
  font-size: 1.2rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.2s ease, transform 0.15s ease;
}

.sound-toggle:hover {
  background: rgba(255, 255, 255, 0.25);
  transform: scale(1.05);
}

.sound-toggle.muted {
  opacity: 0.6;
}

/* App Shell Layout */
.app-shell {
  width: 100%;
  max-width: 820px;
  padding: 36px 20px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

/* Screen Transitions */
.screen {
  display: none;
}

.screen.active {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

/* Card Components */
.card {
  background: var(--card-bg);
  border-radius: var(--radius-lg);
  padding: 28px 32px;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.03);
  border: 1px solid var(--border-color);
}

.hero h1 {
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--primary-blue);
  margin-bottom: 8px;
  border-bottom: 2px solid var(--accent-crimson);
  padding-bottom: 6px;
  display: inline-block;
}

.subtitle {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin-bottom: 16px;
}

.info-note {
  background-color: #f8f9fa;
  border-left: 4px solid var(--primary-blue);
  padding: 12px 16px;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  font-size: 0.9rem;
  color: var(--text-dark);
}

/* Form Fields & Choices */
.field {
  margin-bottom: 22px;
}

.field label {
  display: block;
  font-weight: 700;
  font-size: 0.95rem;
  color: var(--primary-blue);
  margin-bottom: 10px;
}

.field-note {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 8px;
}

.field input[type="text"] {
  width: 100%;
  padding: 12px 14px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
  font-size: 1rem;
  font-family: inherit;
  outline: none;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.field input[type="text"]:focus {
  border-color: var(--primary-blue);
  box-shadow: 0 0 0 3px rgba(0, 51, 153, 0.1);
}

/* Choice Cards Grid */
.choice-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
}

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

.choice-card {
  border: 1px solid var(--border-color);
  background: #ffffff;
  border-radius: var(--radius-md);
  padding: 14px 10px;
  text-align: center;
  cursor: pointer;
  transition: all 0.2s ease;
}

.choice-card:hover {
  border-color: var(--primary-blue);
  background: #f0f4ff;
}

.choice-card .icon {
  font-size: 1.3rem;
  display: block;
  margin-bottom: 4px;
}

.choice-card .label {
  font-weight: 700;
  font-size: 0.9rem;
  color: var(--text-dark);
  display: block;
}

.choice-card .sub {
  font-size: 0.75rem;
  color: var(--text-muted);
  display: block;
  margin-top: 2px;
}

.choice-card.selected {
  border-color: var(--primary-blue);
  background: #e6edff;
  box-shadow: 0 0 0 2px rgba(0, 51, 153, 0.15);
}

.choice-card.selected .label {
  color: var(--primary-blue);
}

/* Consonant Picker Grid */
.consonant-picker {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 8px;
  margin-top: 10px;
  max-height: 200px;
  overflow-y: auto;
  padding: 4px;
}

.consonant-btn {
  border: 1px solid var(--border-color);
  background: #ffffff;
  border-radius: var(--radius-sm);
  padding: 8px;
  text-align: center;
  cursor: pointer;
  font-family: var(--font-deva);
  font-size: 1.2rem;
  transition: all 0.15s ease;
}

.consonant-btn:hover {
  border-color: var(--primary-blue);
  background: #f0f4ff;
}

.consonant-btn.selected {
  border-color: var(--accent-crimson);
  background: #fff0f2;
  color: var(--accent-crimson);
  font-weight: bold;
}

/* Buttons */
.btn {
  font-family: inherit;
  font-weight: 700;
  font-size: 0.95rem;
  border-radius: var(--radius-md);
  padding: 12px 20px;
  cursor: pointer;
  transition: all 0.2s ease;
  border: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
}

.btn-primary {
  background: var(--primary-blue);
  color: #ffffff;
  width: 100%;
}

.btn-primary:hover {
  background: #002266;
}

.btn-secondary {
  background: #ffffff;
  color: var(--primary-blue);
  border: 1px solid var(--primary-blue);
}

.btn-secondary:hover {
  background: #f0f4ff;
}

.btn-ghost {
  background: transparent;
  color: var(--text-dark);
  border: 1px solid var(--border-color);
}

.btn-ghost:hover {
  background: #f5f5f5;
  border-color: #ccc;
}

.btn-row {
  display: flex;
  gap: 10px;
}

.btn-row .btn {
  flex: 1;
}

/* Review Grids & Barakhadi Table */
.learn-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(80px, 1fr));
  gap: 10px;
  margin-top: 14px;
}

.learn-tile {
  border: 1px solid var(--border-color);
  background: #ffffff;
  border-radius: var(--radius-sm);
  padding: 10px 4px;
  text-align: center;
}

.learn-tile .deva {
  font-family: var(--font-deva);
  font-size: 1.6rem;
  color: var(--primary-blue);
}

.learn-tile .rom {
  font-size: 0.8rem;
  color: var(--text-muted);
  font-weight: 600;
}

.barakhadi-scroll {
  overflow-x: auto;
  margin-top: 14px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
}

.barakhadi-table {
  width: 100%;
  border-collapse: collapse;
  text-align: center;
}

.barakhadi-table th, 
.barakhadi-table td {
  padding: 10px 14px;
  border: 1px solid var(--border-color);
  font-size: 0.95rem;
}

.barakhadi-table th {
  background-color: var(--primary-blue);
  color: #ffffff;
  font-weight: 600;
}

.barakhadi-table td.consonant-cell {
  font-weight: bold;
  background-color: #f0f4ff;
  color: var(--primary-blue);
  font-family: var(--font-deva);
}

/* Game Interface Styles */
.info-bar {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px 20px;
  background: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 16px;
  font-size: 0.9rem;
}

.info-item {
  display: flex;
  justify-content: space-between;
}

.info-item .k {
  color: var(--text-muted);
}

.info-item .v {
  font-weight: 700;
  color: var(--primary-blue);
}

.progress-track {
  grid-column: 1 / -1;
  height: 8px;
  border-radius: 999px;
  background: #e0e0e0;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: var(--primary-blue);
  border-radius: 999px;
  transition: width 0.3s ease;
}

.question-card {
  text-align: center;
}

.question-prompt {
  font-size: 1rem;
  color: var(--text-muted);
  margin-bottom: 12px;
}

.letter-display {
  font-family: var(--font-deva);
  font-size: 4.5rem;
  color: var(--primary-blue);
  margin: 10px 0 20px;
}

.answer-input {
  width: 100%;
  padding: 14px;
  font-size: 1.1rem;
  text-align: center;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
  margin-bottom: 12px;
  outline: none;
}

.answer-input:focus {
  border-color: var(--primary-blue);
}

.mc-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.mc-option {
  border: 1px solid var(--border-color);
  background: #ffffff;
  border-radius: var(--radius-md);
  padding: 14px;
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-dark);
  cursor: pointer;
  transition: all 0.15s ease;
}

.mc-option.deva {
  font-family: var(--font-deva);
  font-size: 1.6rem;
}

.mc-option:hover:not(:disabled) {
  border-color: var(--primary-blue);
  background: #f0f4ff;
}

.mc-option.correct {
  background: #e6f4ea;
  border-color: #137333;
  color: #137333;
}

.mc-option.incorrect {
  background: #fce8e6;
  border-color: var(--accent-crimson);
  color: var(--accent-crimson);
}

/* Feedback Box */
.feedback-panel {
  margin-top: 16px;
  border-radius: var(--radius-md);
  padding: 16px;
  text-align: center;
  display: none;
}

.feedback-panel.show {
  display: block;
}

.feedback-panel.correct {
  background: #e6f4ea;
  border: 1px solid #ceead6;
}

.feedback-panel.incorrect {
  background: #fce8e6;
  border: 1px solid #fad2cf;
}

.feedback-title {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 4px;
}

.feedback-panel.correct .feedback-title { color: #137333; }
.feedback-panel.incorrect .feedback-title { color: var(--accent-crimson); }

/* Results Screen */
.results-title {
  font-size: 1.5rem;
  color: var(--primary-blue);
  text-align: center;
  margin-bottom: 12px;
  font-weight: 700;
}

.stat-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  margin: 16px 0;
}

.stat-tile {
  background: #f8f9fa;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 12px;
  text-align: center;
}

.stat-tile .num {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--primary-blue);
}

.stat-tile .lab {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.perf-msg {
  text-align: center;
  background: #f0f4ff;
  border-radius: var(--radius-md);
  padding: 14px;
  color: var(--primary-blue);
  font-weight: 600;
  margin-bottom: 16px;
}

/* Mistake Review List */
.mistake-item {
  display: flex;
  align-items: center;
  gap: 16px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 12px 16px;
  margin-bottom: 10px;
}

.mistake-item .deva {
  font-family: var(--font-deva);
  font-size: 1.8rem;
  color: var(--primary-blue);
  width: 50px;
  text-align: center;
}

.mistake-item .right { color: #137333; font-weight: bold; }
.mistake-item .wrong { color: var(--accent-crimson); }

footer.tiny {
  text-align: center;
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-top: 12px;
}

/* Responsive adjustments */
@media (max-width: 600px) {
  .choice-grid {
    grid-template-columns: 1fr;
  }
  .choice-grid.cols-2 {
    grid-template-columns: 1fr;
  }
  .consonant-picker {
    grid-template-columns: repeat(4, 1fr);
  }
  .mc-grid {
    grid-template-columns: 1fr;
  }
  .topbar {
    padding: 20px;
  }
  .brand {
    font-size: 1.3rem;
  }
}