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

:root {
  --bg-primary: #0a0e17;
  --bg-secondary: #111827;
  --bg-card: #1a2332;
  --text-primary: #e2e8f0;
  --text-secondary: #94a3b8;
  --accent: #00e5ff;
  --accent-glow: #00e5ff66;
  --success: #00e676;
  --success-glow: #00e67666;
  --error: #ff5252;
  --error-glow: #ff525266;
  --warning: #ffd740;
  --border: #2a3a4e;
  --radius: 12px;
  --radius-sm: 8px;
  --transition: 0.2s ease;
}

body {
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 20px;
  background-image:
    radial-gradient(ellipse at 50% 0%, rgba(0, 229, 255, 0.06) 0%, transparent 60%),
    radial-gradient(ellipse at 50% 100%, rgba(0, 229, 255, 0.03) 0%, transparent 60%);
}

.game-container {
  width: 100%;
  max-width: 640px;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

header {
  text-align: center;
}

header h1 {
  font-size: 2rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--accent), #00b8d4);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 16px;
  letter-spacing: 2px;
}

.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
}

.stat-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 10px 8px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
}

.stat-label {
  font-size: 0.7rem;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 1px;
}

.stat-value {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--accent);
  font-variant-numeric: tabular-nums;
}

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

.stat-item.timer-stat.urgent .stat-value {
  color: var(--error);
  animation: pulse 0.5s ease-in-out infinite;
}

.game-screen {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px 24px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 24px;
}

.morse-display {
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
}

.morse-visual {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  flex-wrap: wrap;
  min-height: 48px;
  padding: 16px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  width: 100%;
  transition: background var(--transition), border-color var(--transition);
}

.morse-visual .placeholder {
  color: var(--text-secondary);
  font-size: 1rem;
  opacity: 0.6;
}

.morse-char {
  display: flex;
  gap: 3px;
  padding: 4px 8px;
  border-radius: 4px;
}

.morse-dot, .morse-dash {
  width: 10px;
  height: 10px;
  border-radius: 2px;
  background: var(--accent);
  box-shadow: 0 0 8px var(--accent-glow);
  transition: background var(--transition), box-shadow var(--transition);
}

.morse-dash {
  width: 24px;
}

.morse-text {
  font-size: 1.1rem;
  font-family: 'Courier New', 'Consolas', monospace;
  color: var(--text-secondary);
  letter-spacing: 3px;
  min-height: 24px;
  text-align: center;
  word-break: break-all;
}

.play-audio-btn {
  display: flex;
  align-items: center;
  gap: 6px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--accent);
  padding: 8px 16px;
  border-radius: 20px;
  cursor: pointer;
  font-size: 0.85rem;
  transition: all var(--transition);
}

.play-audio-btn:hover {
  background: var(--accent);
  color: var(--bg-primary);
  box-shadow: 0 0 20px var(--accent-glow);
}

.play-audio-btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.morse-visual.playing .morse-dot,
.morse-visual.playing .morse-dash {
  background: var(--warning);
  box-shadow: 0 0 16px var(--warning);
}

.morse-visual.correct {
  border-color: var(--success);
  box-shadow: 0 0 24px var(--success-glow);
}

.morse-visual.wrong {
  border-color: var(--error);
  box-shadow: 0 0 24px var(--error-glow);
  animation: shake 0.4s ease;
}

.input-area {
  width: 100%;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

#answerInput {
  width: 100%;
  padding: 14px 16px;
  font-size: 1.1rem;
  background: var(--bg-card);
  border: 2px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  outline: none;
  text-align: center;
  letter-spacing: 2px;
  transition: border-color var(--transition), box-shadow var(--transition);
}

#answerInput:focus {
  border-color: var(--accent);
  box-shadow: 0 0 16px var(--accent-glow);
}

#answerInput::placeholder {
  color: var(--text-secondary);
  opacity: 0.5;
  letter-spacing: 1px;
}

.button-row {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.btn-primary {
  flex: 1;
  min-width: 100px;
  padding: 12px 20px;
  font-size: 1rem;
  font-weight: 600;
  background: linear-gradient(135deg, var(--accent), #0097a7);
  color: var(--bg-primary);
  border: none;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition);
}

.btn-primary:hover {
  box-shadow: 0 0 20px var(--accent-glow);
  transform: translateY(-1px);
}

.btn-primary:active {
  transform: translateY(0);
}

.btn-primary:disabled {
  opacity: 0.4;
  cursor: not-allowed;
  transform: none;
  box-shadow: none;
}

.btn-secondary {
  padding: 10px 16px;
  font-size: 0.85rem;
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-secondary);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition);
}

.btn-secondary:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.btn-large {
  width: 100%;
  padding: 16px;
  font-size: 1.2rem;
}

.feedback {
  min-height: 28px;
  font-size: 1rem;
  font-weight: 600;
  text-align: center;
  transition: all var(--transition);
}

.feedback.correct {
  color: var(--success);
  text-shadow: 0 0 10px var(--success-glow);
}

.feedback.wrong {
  color: var(--error);
  text-shadow: 0 0 10px var(--error-glow);
}

.feedback.timeout {
  color: var(--warning);
}

.feedback.hint {
  color: var(--warning);
  font-size: 0.9rem;
}

.game-over {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 40px 24px;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 20px;
}

.game-over h2 {
  font-size: 2rem;
  color: var(--accent);
}

.final-score {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
}

.final-label {
  font-size: 0.85rem;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 2px;
}

.final-value {
  font-size: 3rem;
  font-weight: 800;
  color: var(--accent);
  text-shadow: 0 0 20px var(--accent-glow);
}

.final-stats {
  color: var(--text-secondary);
  line-height: 1.8;
}

.final-stats span {
  color: var(--accent);
  font-weight: 600;
}

.reference-section {
  width: 100%;
}

.reference-toggle {
  width: 100%;
  padding: 12px 16px;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-size: 0.9rem;
  cursor: pointer;
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 8px;
  transition: all var(--transition);
}

.reference-toggle:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.toggle-arrow {
  transition: transform var(--transition);
  font-size: 0.7rem;
}

.reference-toggle.open .toggle-arrow {
  transform: rotate(180deg);
}

.reference {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-top: none;
  border-radius: 0 0 var(--radius-sm) var(--radius-sm);
  padding: 16px;
  transition: all 0.3s ease;
  overflow: hidden;
}

.reference.hidden {
  display: none;
}

.ref-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.ref-col h3 {
  font-size: 0.8rem;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 2px;
  margin-bottom: 10px;
}

.ref-items {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4px;
}

.ref-item {
  display: flex;
  justify-content: space-between;
  padding: 4px 8px;
  font-size: 0.8rem;
  border-radius: 4px;
  transition: background var(--transition);
}

.ref-item:hover {
  background: var(--bg-card);
}

.ref-item .ref-char {
  color: var(--accent);
  font-weight: 700;
  width: 24px;
}

.ref-item .ref-morse {
  color: var(--text-secondary);
  font-family: 'Courier New', monospace;
  letter-spacing: 1px;
}

.hidden {
  display: none !important;
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  20% { transform: translateX(-6px); }
  40% { transform: translateX(6px); }
  60% { transform: translateX(-4px); }
  80% { transform: translateX(4px); }
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes scorePopup {
  0% { transform: scale(0.5); opacity: 0; }
  50% { transform: scale(1.2); }
  100% { transform: scale(1); opacity: 1; }
}

.feedback.pop {
  animation: scorePopup 0.4s ease;
}

@media (max-width: 480px) {
  .game-container { gap: 16px; }
  header h1 { font-size: 1.5rem; }
  .stats { grid-template-columns: repeat(2, 1fr); }
  .game-screen { padding: 20px 16px; gap: 16px; }
  .morse-visual { padding: 12px; }
  .button-row { flex-direction: column; }
  .btn-secondary { width: 100%; }
  .ref-grid { grid-template-columns: 1fr; }
  .ref-items { grid-template-columns: 1fr 1fr 1fr; }
}