/* ========================================
   CSS Custom Properties
   ======================================== */
:root {
  --color-bg: #1a1a2e;
  --color-surface: #16213e;
  --color-primary: #e94560;
  --color-secondary: #0f3460;
  --color-accent: #f5c518;
  --color-success: #00c853;
  --color-danger: #ff1744;
  --color-text: #ffffff;
  --color-text-muted: #a0a0b0;
  --font-main: 'Segoe UI', system-ui, -apple-system, sans-serif;
  --radius: 12px;
  --transition-fast: 150ms ease;
  --transition-normal: 300ms ease;
}

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

body {
  font-family: var(--font-main);
  background: var(--color-bg);
  color: var(--color-text);
  min-height: 100dvh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

#app {
  width: 100%;
  max-width: 480px;
  padding: 20px;
  position: relative;
}

/* ========================================
   Screen Management
   ======================================== */
.screen {
  display: none;
  flex-direction: column;
  align-items: center;
  gap: 24px;
}

.screen.active {
  display: flex;
  animation: fadeIn 0.3s ease;
}

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

/* ========================================
   Menu Screen
   ======================================== */
.title {
  font-size: 2.4rem;
  text-align: center;
  line-height: 1.2;
  letter-spacing: -0.02em;
}

.title-highlight {
  color: var(--color-accent);
  font-size: 3rem;
  text-shadow: 0 0 30px rgba(245, 197, 24, 0.3);
}

.table-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
  width: 100%;
}

.table-btn {
  background: var(--color-surface);
  border: 2px solid var(--color-secondary);
  color: var(--color-text);
  font-size: 1.2rem;
  font-weight: 700;
  padding: 14px 0;
  border-radius: var(--radius);
  cursor: pointer;
  transition: all var(--transition-fast);
  font-family: var(--font-main);
}

.table-btn:hover {
  border-color: var(--color-primary);
  background: var(--color-secondary);
  transform: scale(1.05);
}

.table-btn:active {
  transform: scale(0.97);
}

.mix-btn {
  grid-column: 1 / -1;
  background: linear-gradient(135deg, var(--color-primary), #c2185b);
  border-color: var(--color-primary);
  font-size: 1.4rem;
  padding: 16px 0;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.mix-btn:hover {
  background: linear-gradient(135deg, #ff6b81, var(--color-primary));
  border-color: #ff6b81;
}

/* ========================================
   Welcome Screen
   ======================================== */
.welcome-form {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  width: 100%;
}

.name-label {
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--color-text-muted);
}

.name-input {
  background: var(--color-surface);
  border: 3px solid var(--color-secondary);
  color: var(--color-text);
  font-size: 1.6rem;
  font-weight: 700;
  text-align: center;
  width: 100%;
  max-width: 300px;
  padding: 14px;
  border-radius: var(--radius);
  outline: none;
  font-family: var(--font-main);
  transition: border-color var(--transition-fast);
}

.name-input:focus {
  border-color: var(--color-accent);
}

.lets-go-btn {
  width: 100%;
  max-width: 300px;
  padding: 16px;
  font-size: 1.3rem;
  font-weight: 700;
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  font-family: var(--font-main);
  background: linear-gradient(135deg, var(--color-primary), #c2185b);
  color: var(--color-text);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  transition: all var(--transition-fast);
}

.lets-go-btn:hover {
  transform: scale(1.02);
  box-shadow: 0 4px 20px rgba(233, 69, 96, 0.4);
}

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

.player-greeting {
  font-size: 1.1rem;
  color: var(--color-text-muted);
}

.leaderboard-btn {
  width: 100%;
  padding: 14px;
  font-size: 1.1rem;
  font-weight: 700;
  border: 2px solid var(--color-accent);
  border-radius: var(--radius);
  cursor: pointer;
  font-family: var(--font-main);
  background: transparent;
  color: var(--color-accent);
  transition: all var(--transition-fast);
}

.leaderboard-btn:hover {
  background: rgba(245, 197, 24, 0.1);
  transform: scale(1.02);
}

.change-player-btn {
  background: none;
  border: none;
  color: var(--color-text-muted);
  font-size: 0.9rem;
  cursor: pointer;
  font-family: var(--font-main);
  padding: 4px 8px;
  transition: color var(--transition-fast);
}

.change-player-btn:hover {
  color: var(--color-text);
}

/* ========================================
   Countdown Screen
   ======================================== */
.countdown-number {
  font-size: 8rem;
  font-weight: 900;
  color: var(--color-accent);
  text-shadow: 0 0 40px rgba(245, 197, 24, 0.5);
  animation: countdownPulse 0.6s ease;
}

@keyframes countdownPulse {
  0% { transform: scale(1.6); opacity: 0; }
  50% { opacity: 1; }
  100% { transform: scale(1); opacity: 1; }
}

/* ========================================
   Game Screen
   ======================================== */
.game-header {
  width: 100%;
  display: flex;
  align-items: center;
  gap: 16px;
}

.timer-container {
  flex: 1;
  display: flex;
  align-items: center;
  gap: 10px;
}

.timer-bar-bg {
  flex: 1;
  height: 14px;
  background: var(--color-surface);
  border-radius: 7px;
  overflow: hidden;
}

.timer-bar {
  height: 100%;
  width: 100%;
  background: linear-gradient(90deg, var(--color-success), #69f0ae);
  border-radius: 7px;
  transition: width 1s linear;
}

.timer-bar.warning {
  background: linear-gradient(90deg, var(--color-accent), #ffeb3b);
}

.timer-bar.danger {
  background: linear-gradient(90deg, var(--color-danger), #ff5252);
  animation: timerPulse 0.5s ease infinite;
}

@keyframes timerPulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.6; }
}

.timer-text {
  font-size: 1.4rem;
  font-weight: 700;
  min-width: 2.2ch;
  text-align: right;
  font-variant-numeric: tabular-nums;
}

.score-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  background: var(--color-surface);
  padding: 6px 16px;
  border-radius: var(--radius);
}

.score-label {
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-text-muted);
}

.score-value {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--color-accent);
  font-variant-numeric: tabular-nums;
  transition: transform var(--transition-fast);
}

.score-value.bump {
  animation: scoreBump 0.3s ease;
}

@keyframes scoreBump {
  0% { transform: scale(1); }
  50% { transform: scale(1.4); }
  100% { transform: scale(1); }
}

.question-area {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 20px;
  padding: 30px 0;
}

.question {
  font-size: 3.2rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  text-align: center;
}

.input-row {
  display: flex;
  gap: 12px;
  align-items: center;
}

.answer-input {
  background: var(--color-surface);
  border: 3px solid var(--color-secondary);
  color: var(--color-text);
  font-size: 2.4rem;
  font-weight: 700;
  text-align: center;
  width: 160px;
  padding: 12px;
  border-radius: var(--radius);
  outline: none;
  font-family: var(--font-main);
  font-variant-numeric: tabular-nums;
  transition: border-color var(--transition-fast);
  -moz-appearance: textfield;
}

.answer-input::-webkit-outer-spin-button,
.answer-input::-webkit-inner-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

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

.answer-input.correct {
  border-color: var(--color-success);
  animation: correctFlash 0.4s ease;
}

.answer-input.wrong {
  border-color: var(--color-danger);
  animation: shake 0.4s ease;
}

@keyframes correctFlash {
  0% { background: var(--color-surface); }
  30% { background: rgba(0, 200, 83, 0.3); }
  100% { background: var(--color-surface); }
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  20% { transform: translateX(-8px); }
  40% { transform: translateX(8px); }
  60% { transform: translateX(-5px); }
  80% { transform: translateX(5px); }
}

.feedback {
  font-size: 1.4rem;
  font-weight: 700;
  min-height: 2em;
  display: flex;
  align-items: center;
}

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

.feedback.wrong {
  color: var(--color-danger);
}

.streak-container {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--color-accent);
  min-height: 1.6em;
}

/* ========================================
   Results Screen
   ======================================== */
.results-title {
  font-size: 2.2rem;
  text-align: center;
}

.results-stats {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
  width: 100%;
}

.stat {
  background: var(--color-surface);
  border-radius: var(--radius);
  padding: 16px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
}

.stat-value {
  font-size: 2.4rem;
  font-weight: 800;
  color: var(--color-accent);
}

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

.new-high-score {
  display: none;
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--color-accent);
  text-shadow: 0 0 20px rgba(245, 197, 24, 0.5);
  animation: highScorePulse 1s ease infinite;
}

.new-high-score.visible {
  display: block;
}

@keyframes highScorePulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.08); }
}

.wrong-answers-review {
  width: 100%;
}

.wrong-answers-review h3 {
  font-size: 1rem;
  color: var(--color-text-muted);
  margin-bottom: 8px;
}

.wrong-answer-item {
  background: var(--color-surface);
  border-left: 3px solid var(--color-danger);
  padding: 8px 12px;
  border-radius: 0 var(--radius) var(--radius) 0;
  margin-bottom: 6px;
  font-size: 0.95rem;
}

.wrong-answer-item .correct-answer {
  color: var(--color-success);
  font-weight: 700;
}

.play-again-btn,
.menu-btn {
  width: 100%;
  padding: 16px;
  font-size: 1.2rem;
  font-weight: 700;
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  font-family: var(--font-main);
  transition: all var(--transition-fast);
}

.play-again-btn {
  background: linear-gradient(135deg, var(--color-primary), #c2185b);
  color: var(--color-text);
}

.play-again-btn:hover {
  transform: scale(1.02);
  box-shadow: 0 4px 20px rgba(233, 69, 96, 0.4);
}

.menu-btn {
  background: var(--color-surface);
  color: var(--color-text-muted);
  border: 2px solid var(--color-secondary);
}

.menu-btn:hover {
  border-color: var(--color-text-muted);
  color: var(--color-text);
}

/* ========================================
   Leaderboard Screen
   ======================================== */
.leaderboard-title {
  font-size: 2.2rem;
  text-align: center;
  color: var(--color-accent);
}

.leaderboard-table {
  width: 100%;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.lb-header,
.lb-row {
  display: grid;
  grid-template-columns: 36px 1fr 60px 60px;
  gap: 8px;
  align-items: center;
  padding: 10px 12px;
  border-radius: var(--radius);
  font-size: 0.95rem;
}

.lb-header {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-text-muted);
  padding-bottom: 4px;
}

.lb-row {
  background: var(--color-surface);
}

.lb-row.gold {
  border: 2px solid var(--color-accent);
  background: rgba(245, 197, 24, 0.08);
}

.lb-row.silver {
  border: 2px solid #b0bec5;
  background: rgba(176, 190, 197, 0.05);
}

.lb-row.bronze {
  border: 2px solid #cd7f32;
  background: rgba(205, 127, 50, 0.05);
}

.lb-rank {
  font-weight: 800;
  text-align: center;
  font-size: 1.1rem;
}

.lb-name {
  font-weight: 600;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.lb-score {
  font-weight: 800;
  color: var(--color-accent);
  text-align: right;
}

.lb-table {
  font-weight: 600;
  color: var(--color-text-muted);
  text-align: right;
}

.lb-empty {
  text-align: center;
  color: var(--color-text-muted);
  padding: 30px 0;
  font-size: 1.1rem;
}

/* ========================================
   Confetti Canvas
   ======================================== */
#confetti-canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 1000;
}

/* ========================================
   Responsive
   ======================================== */
@media (max-width: 400px) {
  .title { font-size: 1.8rem; }
  .title-highlight { font-size: 2.2rem; }
  .question { font-size: 2.4rem; }
  .answer-input { font-size: 1.8rem; width: 130px; }
  .table-grid { gap: 6px; }
  .table-btn { padding: 10px 0; font-size: 1rem; }
}