/* ============================================
   ASCII Audio Game - Styles
   Modern, polished dark theme
   ============================================ */

/* CSS Variables */
:root {
  --bg-dark: #0a0a0f;
  --bg-card: #12121a;
  --bg-card-hover: #1a1a25;
  --primary: #00d4ff;
  --primary-dim: #00a0cc;
  --accent: #7c3aed;
  --success: #00ff88;
  --error: #ff4466;
  --warning: #ffaa00;
  --text: #ffffff;
  --text-dim: #888899;
  --text-muted: #555566;

  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'SF Mono', 'Fira Code', 'Consolas', monospace;

  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;

  --shadow-glow: 0 0 30px rgba(0, 212, 255, 0.3);
  --shadow-card: 0 4px 20px rgba(0, 0, 0, 0.4);

  --transition-fast: 0.15s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
}

/* Reset & Base */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html, body {
  height: 100%;
  overflow: hidden;
}

body {
  font-family: var(--font-sans);
  background: var(--bg-dark);
  color: var(--text);
  line-height: 1.5;
}

#app {
  width: 100%;
  height: 100%;
  position: relative;
}

/* Screens */
.screen {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-start;
  padding: 1rem;
  padding-top: 4rem;
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
  transition: opacity var(--transition-normal),
              transform var(--transition-normal),
              visibility var(--transition-normal);
  overflow-y: auto;
}

.screen.active {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.screen-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1rem 2rem;
  background: var(--bg-dark);
  z-index: 100;
  border-bottom: 1px solid var(--bg-card);
}

/* Center content screens (menu, loading, results) */
#screen-loading,
#screen-menu,
#screen-results {
  justify-content: center;
  padding-top: 1rem;
}

.screen-header h2 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-dim);
}

/* Logo */
.logo {
  font-size: 3rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 0.5rem;
}

.logo .accent {
  color: var(--primary);
}

.tagline {
  color: var(--text-dim);
  font-size: 1.1rem;
  margin-bottom: 2rem;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.875rem 1.5rem;
  font-size: 1rem;
  font-weight: 600;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
  position: relative;
  z-index: 5;
}

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

.btn.played {
  background: var(--bg-lighter);
  color: var(--text-dim);
  opacity: 0.6;
}

.btn-primary {
  background: var(--primary);
  color: var(--bg-dark);
}

.btn-primary:hover:not(:disabled) {
  background: var(--text);
  box-shadow: var(--shadow-glow);
}

.btn-secondary {
  background: var(--bg-card);
  color: var(--text);
  border: 1px solid var(--text-muted);
}

.btn-secondary:hover:not(:disabled) {
  background: var(--bg-card-hover);
  border-color: var(--primary);
}

.btn-accent {
  background: var(--accent);
  color: var(--text);
}

.btn-accent:hover:not(:disabled) {
  filter: brightness(1.2);
}

.btn-ghost {
  background: transparent;
  color: var(--text-dim);
}

.btn-ghost:hover:not(:disabled) {
  color: var(--text);
}

.btn-large {
  padding: 1.25rem 2.5rem;
  font-size: 1.25rem;
  border-radius: var(--radius-lg);
}

.btn-small {
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
}

.btn-icon {
  font-size: 1.2em;
}

.btn-back {
  background: none;
  border: none;
  color: var(--text-dim);
  font-size: 1rem;
  cursor: pointer;
  padding: 0.5rem;
  transition: color var(--transition-fast);
}

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

/* Menu */
.menu-content {
  text-align: center;
}

.menu-buttons {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-bottom: 3rem;
}

.menu-buttons .btn {
  min-width: 250px;
}

.stats-preview {
  display: flex;
  gap: 3rem;
  justify-content: center;
}

.stat {
  text-align: center;
}

.stat-value {
  display: block;
  font-size: 2rem;
  font-weight: 700;
  color: var(--primary);
  font-family: var(--font-mono);
}

.stat-label {
  font-size: 0.75rem;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

.stat.streak .stat-value {
  color: var(--warning);
}

.stat.timer .stat-value {
  color: var(--error);
}

.stat.large .stat-value {
  font-size: 3rem;
}

/* Loading Screen */
.loading-content {
  text-align: center;
}

.loading-bar {
  width: 200px;
  height: 4px;
  background: var(--bg-card);
  border-radius: 2px;
  margin: 1.5rem auto;
  overflow: hidden;
}

.loading-progress {
  height: 100%;
  background: var(--primary);
  width: 0%;
  transition: width var(--transition-fast);
}

.loading-text {
  color: var(--text-dim);
  font-size: 0.875rem;
}

/* Lessons Grid */
.lessons-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
  max-width: 900px;
  width: 100%;
  margin-top: 4rem;
}

.lesson-card {
  background: var(--bg-card);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  cursor: pointer;
  transition: all var(--transition-fast);
  border: 1px solid transparent;
}

.lesson-card:hover {
  background: var(--bg-card-hover);
  border-color: var(--primary);
  transform: translateY(-2px);
}

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

.lesson-card.locked:hover {
  transform: none;
  border-color: transparent;
}

.lesson-card.completed {
  border-color: var(--success);
}

.lesson-number {
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 0.5rem;
}

.lesson-title {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.lesson-chars {
  font-family: var(--font-mono);
  color: var(--primary);
  font-size: 1.1rem;
  letter-spacing: 0.2em;
  margin-bottom: 0.75rem;
}

.lesson-status {
  font-size: 0.875rem;
  color: var(--text-dim);
}

.lesson-status.completed {
  color: var(--success);
}

/* Learn Screen */
.learn-content {
  text-align: center;
  max-width: 500px;
}

.character-display {
  margin-bottom: 2rem;
}

.character-card {
  font-family: var(--font-mono);
  font-size: 5rem;
  font-weight: 700;
  color: var(--primary);
  background: var(--bg-card);
  min-width: 180px;
  max-width: 90vw;
  width: auto;
  padding: 1.5rem 2rem;
  min-height: 140px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-lg);
  margin: 0 auto 1rem;
  box-shadow: var(--shadow-card);
  transition: all var(--transition-fast);
  white-space: nowrap;
}

/* Smaller font for compound/long characters */
.character-card.compound {
  font-size: 2.5rem;
  letter-spacing: 0.1em;
}

.character-card.playing {
  box-shadow: var(--shadow-glow);
  transform: scale(1.05);
}

.character-name {
  color: var(--text-dim);
  font-size: 1rem;
}

.learn-controls {
  margin-bottom: 2rem;
}

.learn-progress {
  color: var(--text-dim);
  font-family: var(--font-mono);
  margin-bottom: 1.5rem;
}

.learn-nav {
  display: flex;
  gap: 1rem;
  justify-content: center;
  margin-bottom: 2rem;
}

/* Quiz Screen */
.quiz-content, .challenge-content {
  text-align: center;
  max-width: 800px;
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.25rem;
}

.quiz-stats, .challenge-stats {
  display: flex;
  justify-content: center;
  gap: 2rem;
  flex-shrink: 0;
}

.quiz-play-area, .challenge-play-area {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  flex-shrink: 0;
  position: relative;
  z-index: 20;
}

.quiz-input-area, .challenge-input-area {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
  flex-shrink: 0;
}

.quiz-input {
  font-family: var(--font-mono);
  font-size: 1.5rem;
  padding: 1rem 1.5rem;
  background: var(--bg-card);
  border: 2px solid var(--text-muted);
  border-radius: var(--radius-md);
  color: var(--text);
  width: 300px;
  text-align: center;
  transition: border-color var(--transition-fast);
}

.quiz-input:focus {
  outline: none;
  border-color: var(--primary);
}

.quiz-input.correct {
  border-color: var(--success);
  animation: pulse-success 0.3s ease;
}

.quiz-input.incorrect {
  border-color: var(--error);
  animation: shake 0.3s ease;
}

/* Feedback */
.feedback-display {
  min-height: 60px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.25rem;
  opacity: 0;
  transition: opacity var(--transition-fast);
}

.feedback-display.show {
  opacity: 1;
}

.feedback-icon {
  font-size: 2rem;
}

.feedback-display.correct .feedback-icon::before {
  content: '✓';
  color: var(--success);
}

.feedback-display.incorrect .feedback-icon::before {
  content: '✗';
  color: var(--error);
}

.feedback-text {
  font-size: 1.25rem;
  font-weight: 600;
}

.feedback-display.correct .feedback-text {
  color: var(--success);
}

.feedback-display.incorrect .feedback-text {
  color: var(--error);
}

.feedback-answer {
  font-family: var(--font-mono);
  color: var(--text-dim);
}

/* Sandbox Screen */
.sandbox-content {
  text-align: center;
  max-width: 800px;
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.5rem;
}

.sandbox-hint {
  color: var(--text-dim);
  font-size: 1rem;
}

.sandbox-display {
  margin-bottom: 1rem;
}

/* Results Screen */
.results-content {
  text-align: center;
}

.results-title {
  font-size: 2rem;
  margin-bottom: 2rem;
}

.results-stats {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
  margin-bottom: 2rem;
}

.result-stat {
  background: var(--bg-card);
  padding: 1.5rem;
  border-radius: var(--radius-md);
}

.result-value {
  display: block;
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--primary);
  font-family: var(--font-mono);
}

.result-label {
  font-size: 0.875rem;
  color: var(--text-dim);
}

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

/* Overlay */
.overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.9);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  cursor: pointer;
}

.overlay.hidden {
  display: none;
}

.overlay-content {
  text-align: center;
  color: var(--text-dim);
}

/* Particles */
#particles {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 100;
}

.particle {
  position: absolute;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  pointer-events: none;
}

/* Animations */
@keyframes shake {
  0%, 100% { transform: translateX(0); }
  20%, 60% { transform: translateX(-5px); }
  40%, 80% { transform: translateX(5px); }
}

@keyframes pulse-success {
  0% { transform: scale(1); }
  50% { transform: scale(1.02); }
  100% { transform: scale(1); }
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

@keyframes glow-pulse {
  0%, 100% { box-shadow: 0 0 20px rgba(0, 212, 255, 0.3); }
  50% { box-shadow: 0 0 40px rgba(0, 212, 255, 0.6); }
}

/* Screen shake effect */
.screen-shake {
  animation: screen-shake 0.3s ease;
}

@keyframes screen-shake {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-3px); }
  75% { transform: translateX(3px); }
}

/* Typed Characters Display */
.typed-chars {
  font-family: var(--font-mono);
  font-size: 1.5rem;
  min-height: 3rem;
  padding: 0.75rem 1.5rem;
  background: var(--bg-card);
  border: 2px solid var(--text-muted);
  border-radius: var(--radius-md);
  color: var(--primary);
  min-width: 280px;
  max-width: 500px;
  text-align: center;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.typed-chars:empty::before {
  content: 'Listen and type...';
  color: var(--text-muted);
  letter-spacing: normal;
}

.typed-chars.correct {
  border-color: var(--success);
  animation: pulse-success 0.3s ease;
}

.typed-chars.incorrect {
  border-color: var(--error);
  animation: shake 0.3s ease;
}

.typed-char {
  display: inline-block;
  padding: 0.25rem 0.5rem;
  background: var(--bg-card-hover);
  border-radius: 4px;
  font-size: 1.25rem;
}

.typed-char.compound {
  font-size: 0.85rem;
  letter-spacing: 0.05em;
}

.input-controls {
  display: flex;
  gap: 0.5rem;
  justify-content: center;
}

/* Virtual Keyboard */
.virtual-keyboard {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  padding: 0.75rem;
  background: var(--bg-card);
  border-radius: var(--radius-md);
  max-width: 650px;
  width: 100%;
  flex-shrink: 0;
  position: relative;
  z-index: 1;
}

.keyboard-row {
  display: flex;
  gap: 0.3rem;
  justify-content: center;
  flex-wrap: wrap;
}

.key {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-width: 42px;
  height: 46px;
  padding: 0.2rem 0.4rem;
  background: var(--bg-card-hover);
  border: 1px solid var(--text-muted);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
  user-select: none;
}

/* Wide keys for compound characters */
.key.compound-key {
  min-width: auto;
  padding: 0.2rem 0.6rem;
}

.key.compound-key .key-label {
  font-size: 0.7rem;
  letter-spacing: 0;
}

.key:hover {
  background: var(--primary);
  border-color: var(--primary);
}

.key:hover .key-label {
  color: var(--bg-dark);
}

.key:hover .key-hint {
  color: var(--bg-dark);
  opacity: 0.7;
}

.key:active,
.key.pressed {
  transform: scale(0.95);
  background: var(--primary);
}

.key-label {
  font-family: var(--font-mono);
  font-size: 0.95rem;
  color: var(--text);
  font-weight: 600;
  line-height: 1;
}

.key-hint {
  font-size: 0.6rem;
  color: var(--text-dim);
  margin-top: 1px;
  line-height: 1;
}

/* Highlight keys for current lesson */
.key.active-lesson {
  border-color: var(--primary);
  box-shadow: 0 0 10px rgba(0, 212, 255, 0.3);
}

.key.disabled {
  opacity: 0.3;
  cursor: not-allowed;
}

.key.disabled:hover {
  background: var(--bg-card-hover);
  border-color: var(--text-muted);
}

/* Responsive */
@media (max-width: 600px) {
  .logo {
    font-size: 2rem;
  }

  .character-card {
    width: 140px;
    height: 140px;
    font-size: 4rem;
  }

  .quiz-input {
    width: 100%;
    max-width: 280px;
  }

  .quiz-stats, .challenge-stats {
    flex-wrap: wrap;
  }

  .results-stats {
    grid-template-columns: 1fr;
  }
}