/* ===== CSS Variables ===== */
:root {
  --bg-gradient-start: #e0f7fa;
  --bg-gradient-end: #f3e5f5;
  --primary: #7c4dff;
  --primary-light: #b388ff;
  --secondary: #ff6d00;
  --success: #00c853;
  --danger: #ff1744;
  --text-dark: #212121;
  --text-light: #ffffff;
  --card-bg: rgba(255, 255, 255, 0.92);
  --shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
  --shadow-strong: 0 8px 32px rgba(0, 0, 0, 0.18);
  --radius: 16px;
  --radius-sm: 10px;
  --font-main: 'Noto Sans TC', sans-serif;
  --game-max-width: 800px;
  --game-height: 70vh;
}

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

body {
  font-family: var(--font-main);
  background: linear-gradient(135deg, var(--bg-gradient-start), var(--bg-gradient-end));
  min-height: 100vh;
  color: var(--text-dark);
  overflow: hidden;
}

#app {
  width: 100%;
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
}

/* ===== Screen Management ===== */
.screen {
  position: absolute;
  width: 100%;
  height: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
  transition: opacity 0.3s ease;
}

.screen.hidden, .hidden {
  display: none !important;
  opacity: 0;
}

.screen.active {
  opacity: 1;
}

/* ===== Menu Screen ===== */
.menu-container {
  background: var(--card-bg);
  border-radius: var(--radius);
  box-shadow: var(--shadow-strong);
  padding: 40px 48px;
  text-align: center;
  max-width: 520px;
  width: 90%;
  animation: fadeInUp 0.5s ease;
}

.game-title {
  font-size: 3rem;
  font-weight: 900;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 4px;
}

.game-subtitle {
  font-size: 1.1rem;
  color: #888;
  margin-bottom: 32px;
  letter-spacing: 2px;
}

.menu-section {
  margin-bottom: 24px;
}

.menu-label {
  display: block;
  font-size: 0.9rem;
  font-weight: 700;
  color: #666;
  margin-bottom: 10px;
  text-align: left;
}

/* Mode Buttons */
.mode-buttons {
  display: flex;
  gap: 12px;
}

.mode-btn {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  padding: 16px 12px;
  border: 3px solid #e0e0e0;
  border-radius: var(--radius-sm);
  background: #fff;
  cursor: pointer;
  transition: all 0.2s ease;
  font-family: var(--font-main);
  font-size: 1rem;
}

.mode-btn:hover {
  border-color: var(--primary-light);
  transform: translateY(-2px);
}

.mode-btn.selected {
  border-color: var(--primary);
  background: linear-gradient(135deg, #ede7f6, #e8eaf6);
  box-shadow: 0 2px 12px rgba(124, 77, 255, 0.2);
}

.mode-icon {
  font-size: 1.8rem;
}

.mode-text {
  font-weight: 700;
  font-size: 0.95rem;
}

/* Content Type Buttons */
.content-buttons {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.content-btn {
  flex: 1;
  min-width: 80px;
  padding: 10px 8px;
  border: 2px solid #e0e0e0;
  border-radius: var(--radius-sm);
  background: #fff;
  cursor: pointer;
  font-family: var(--font-main);
  font-size: 0.85rem;
  font-weight: 700;
  transition: all 0.2s ease;
}

.content-btn:hover {
  border-color: var(--primary-light);
}

.content-btn.selected {
  border-color: var(--primary);
  background: linear-gradient(135deg, #ede7f6, #e8eaf6);
  color: var(--primary);
}

/* Grade Buttons */
.grade-buttons {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
}

.grade-btn {
  padding: 10px;
  border: 2px solid #e0e0e0;
  border-radius: var(--radius-sm);
  background: #fff;
  cursor: pointer;
  font-family: var(--font-main);
  font-size: 0.9rem;
  font-weight: 700;
  transition: all 0.2s ease;
}

.grade-btn:hover {
  border-color: var(--primary-light);
  transform: translateY(-1px);
}

.grade-btn.selected {
  border-color: var(--primary);
  background: var(--primary);
  color: var(--text-light);
  box-shadow: 0 2px 12px rgba(124, 77, 255, 0.3);
}

/* Start Button */
.start-btn {
  display: block;
  width: 100%;
  padding: 16px;
  margin-top: 12px;
  border: none;
  border-radius: var(--radius-sm);
  background: linear-gradient(135deg, var(--primary), #651fff);
  color: var(--text-light);
  font-family: var(--font-main);
  font-size: 1.2rem;
  font-weight: 900;
  cursor: pointer;
  transition: all 0.2s ease;
  box-shadow: 0 4px 16px rgba(124, 77, 255, 0.4);
}

.start-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 24px rgba(124, 77, 255, 0.5);
}

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

/* ===== 難度按鈕 ===== */
.diff-buttons {
  display: flex;
  gap: 10px;
}

.diff-btn {
  flex: 1;
  padding: 10px 8px;
  border: 2px solid #e0e0e0;
  border-radius: var(--radius-sm);
  background: #fff;
  cursor: pointer;
  font-family: var(--font-main);
  font-size: 0.95rem;
  font-weight: 700;
  transition: all 0.2s ease;
}

.diff-btn:hover {
  border-color: var(--primary-light);
  transform: translateY(-1px);
}

.diff-btn.selected {
  border-color: var(--primary);
  background: linear-gradient(135deg, #ede7f6, #e8eaf6);
  color: var(--primary);
  box-shadow: 0 2px 12px rgba(124, 77, 255, 0.2);
}

/* ===== 簡單模式：掉落元素 ===== */
.simple-word {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  padding: 10px 14px !important;
  min-width: 60px;
}

.simple-char {
  font-size: 2.2rem;
  font-weight: 900;
  line-height: 1;
  letter-spacing: 0;
}

.simple-key-hint {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 800;
  color: rgba(255, 255, 255, 0.75);
  background: rgba(0, 0, 0, 0.25);
  border-radius: 4px;
  padding: 1px 6px;
  letter-spacing: 1px;
  text-transform: uppercase;
}

/* ===== 簡單模式：輸入區提示 ===== */
.simple-hint {
  width: 100%;
  padding: 20px;
  background: var(--card-bg);
  border: 4px dashed var(--primary-light);
  border-radius: var(--radius-sm);
  text-align: center;
  font-size: 1.5rem;
  font-weight: 900;
  color: var(--primary);
  letter-spacing: 4px;
  animation: pulse-hint 2s infinite ease-in-out;
}

@keyframes pulse-hint {
  0% { transform: scale(1); opacity: 0.9; }
  50% { transform: scale(1.02); opacity: 1; }
  100% { transform: scale(1); opacity: 0.9; }
}

/* CSV 載入狀態 */
.csv-status {
  margin-top: 10px;
  font-size: 0.8rem;
  font-weight: 600;
  color: #aaa;
  min-height: 1.2em;
  transition: color 0.3s ease;
}

.csv-status.loaded {
  color: var(--success);
}

.csv-status.fallback {
  color: #bbb;
}

/* ===== Game Screen ===== */
#screen-game {
  flex-direction: column;
  padding: 0;
}

/* HUD */
#game-hud {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 24px;
  padding: 12px 20px;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(10px);
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
  z-index: 10;
  width: 100%;
}

.hud-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
}

.hud-label {
  font-size: 0.7rem;
  font-weight: 700;
  color: #999;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.hud-value {
  font-size: 1.5rem;
  font-weight: 900;
  color: var(--primary);
}

#hud-combo {
  color: var(--secondary);
}

.hud-lives {
  font-size: 1.4rem;
  letter-spacing: 4px;
}

.hud-timer {
  color: var(--success);
  transition: color 0.3s;
}

.hud-timer.urgent {
  color: var(--danger);
  animation: pulse 0.6s infinite alternate;
}

.pause-btn {
  margin-left: auto;
  padding: 6px 12px;
  border: 2px solid #e0e0e0;
  border-radius: 8px;
  background: #fff;
  font-size: 1.2rem;
  cursor: pointer;
  transition: all 0.2s ease;
}

.pause-btn:hover {
  border-color: var(--primary);
  background: #f5f5f5;
}

/* Game Container */
#game-container {
  position: relative;
  flex: 1;
  width: 100%;
  max-width: var(--game-max-width);
  margin: 0 auto;
  overflow: hidden;
}

/* Input Area */
#input-area {
  width: 100%;
  max-width: var(--game-max-width);
  margin: 0 auto;
  padding: 12px 20px 20px;
}

#game-input {
  width: 100%;
  padding: 14px 20px;
  border: 3px solid var(--primary-light);
  border-radius: var(--radius-sm);
  background: #fff;
  font-family: var(--font-main);
  font-size: 1.3rem;
  font-weight: 700;
  text-align: center;
  outline: none;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

#game-input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 4px rgba(124, 77, 255, 0.15);
}

/* ===== Falling Words ===== */
.falling-word {
  position: absolute;
  padding: 8px 18px;
  border-radius: 24px;
  font-size: 1.3rem;
  font-weight: 700;
  color: #fff;
  white-space: nowrap;
  cursor: default;
  user-select: none;
  opacity: 1;
  z-index: 5;
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.2);
}

.falling-word.targeted {
  box-shadow: 0 0 0 3px #fff, 0 0 16px rgba(124, 77, 255, 0.6);
  transform: scale(1.08);
  z-index: 6;
}

.falling-word .matched {
  color: #b9f6ca;
}

.falling-word .unmatched {
  opacity: 0.85;
}

/* Word color palette */
.word-color-0 { background: linear-gradient(135deg, #7c4dff, #651fff); box-shadow: 0 4px 12px rgba(124, 77, 255, 0.5); }
.word-color-1 { background: linear-gradient(135deg, #ff6d00, #ff9100); box-shadow: 0 4px 12px rgba(255, 109, 0, 0.5); }
.word-color-2 { background: linear-gradient(135deg, #00bfa5, #1de9b6); box-shadow: 0 4px 12px rgba(0, 191, 165, 0.5); }
.word-color-3 { background: linear-gradient(135deg, #f50057, #ff4081); box-shadow: 0 4px 12px rgba(245, 0, 87, 0.5); }
.word-color-4 { background: linear-gradient(135deg, #2979ff, #448aff); box-shadow: 0 4px 12px rgba(41, 121, 255, 0.5); }
.word-color-5 { background: linear-gradient(135deg, #ff6f00, #ffc400); box-shadow: 0 4px 12px rgba(255, 111, 0, 0.5); }

/* Zhuyin hint (ruby annotation) */
.falling-word rt {
  font-size: 0.55em;
  color: rgba(255, 255, 255, 0.85);
}

/* ===== Floating Score ===== */
.floating-score-popup {
  position: absolute;
  font-size: 1.5rem;
  font-weight: 900;
  color: #ffeb3b;
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.4);
  pointer-events: none;
  z-index: 25;
  animation: floatUpFade 1s cubic-bezier(0.175, 0.885, 0.32, 1.275) forwards;
}

/* ===== Meaning Popup ===== */
.meaning-popup {
  position: absolute;
  padding: 6px 14px;
  border-radius: 8px;
  background: rgba(0, 0, 0, 0.75);
  color: #fff;
  font-size: 0.9rem;
  font-weight: 700;
  white-space: nowrap;
  pointer-events: none;
  z-index: 20;
  animation: floatUpFade 1.5s ease forwards;
}

/* ===== Combo Popup ===== */
.combo-popup {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-size: 2.5rem;
  font-weight: 900;
  color: var(--secondary);
  text-shadow: 0 2px 8px rgba(255, 109, 0, 0.4);
  pointer-events: none;
  z-index: 30;
  animation: comboBounce 0.8s ease forwards;
}

/* ===== Overlay (Pause) ===== */
.overlay {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 100;
  backdrop-filter: blur(4px);
}

.overlay.hidden {
  display: none;
}

.overlay-content {
  background: var(--card-bg);
  border-radius: var(--radius);
  padding: 40px;
  text-align: center;
  box-shadow: var(--shadow-strong);
}

.overlay-content h2 {
  font-size: 2rem;
  margin-bottom: 24px;
  color: var(--primary);
}

.menu-action-btn {
  display: block;
  width: 200px;
  margin: 10px auto;
  padding: 12px;
  border: none;
  border-radius: var(--radius-sm);
  background: var(--primary);
  color: var(--text-light);
  font-family: var(--font-main);
  font-size: 1rem;
  font-weight: 700;
  cursor: pointer;
  transition: all 0.2s ease;
}

.menu-action-btn:hover {
  opacity: 0.9;
  transform: translateY(-1px);
}

.menu-action-btn.secondary {
  background: #e0e0e0;
  color: var(--text-dark);
}

/* ===== Summary Screen ===== */
.summary-container {
  background: var(--card-bg);
  border-radius: var(--radius);
  box-shadow: var(--shadow-strong);
  padding: 36px 40px;
  text-align: center;
  max-width: 600px;
  width: 90%;
  max-height: 85vh;
  overflow-y: auto;
  animation: fadeInUp 0.5s ease;
}

.summary-title {
  font-size: 2rem;
  font-weight: 900;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 20px;
}

.summary-stats {
  display: flex;
  justify-content: center;
  gap: 24px;
  margin-bottom: 24px;
  flex-wrap: wrap;
}

.stat-card {
  background: #f5f5f5;
  border-radius: var(--radius-sm);
  padding: 16px 24px;
  min-width: 120px;
}

.stat-value {
  font-size: 2rem;
  font-weight: 900;
  color: var(--primary);
}

.stat-label {
  font-size: 0.8rem;
  color: #888;
  font-weight: 700;
}

.stat-card.new-record {
  background: linear-gradient(135deg, #fff9c4, #fff59d);
  box-shadow: 0 0 16px rgba(255, 213, 79, 0.6);
  border: 1px solid #ffd54f;
  transform: scale(1.05);
}

.record-badge {
  background: #ff6d00;
  color: #fff;
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.7rem;
  margin-left: 4px;
  animation: pulse 1s infinite alternate;
}

@keyframes pulse {
  from { transform: scale(1); }
  to { transform: scale(1.1); }
}

/* Summary Word List */
.summary-words {
  margin-bottom: 20px;
}

.summary-words h3 {
  font-size: 1rem;
  color: #666;
  margin-bottom: 12px;
  text-align: left;
}

.word-review-list {
  list-style: none;
  text-align: left;
}

.word-review-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 12px;
  border-radius: 8px;
  margin-bottom: 4px;
  font-size: 0.9rem;
}

.word-review-item.success {
  background: #e8f5e9;
}

.word-review-item.missed {
  background: #ffebee;
}

.word-review-item .word-status {
  font-size: 1rem;
}

.word-review-item .word-text {
  font-weight: 700;
  min-width: 80px;
}

.word-review-item .word-meaning {
  color: #666;
  flex: 1;
}

/* ===== Animations ===== */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes wordSpawn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

@keyframes wordDestroy {
  0% {
    transform: scale(1);
    opacity: 1;
  }
  50% {
    transform: scale(1.4);
    opacity: 0.6;
  }
  100% {
    transform: scale(0);
    opacity: 0;
  }
}

@keyframes floatUpFade {
  0% {
    opacity: 1;
    transform: translateY(0);
  }
  100% {
    opacity: 0;
    transform: translateY(-60px);
  }
}

@keyframes comboBounce {
  0% {
    opacity: 0;
    transform: translate(-50%, -50%) scale(0.3);
  }
  40% {
    opacity: 1;
    transform: translate(-50%, -50%) scale(1.2);
  }
  60% {
    transform: translate(-50%, -50%) scale(0.95);
  }
  75% {
    transform: translate(-50%, -50%) scale(1.05);
  }
  100% {
    opacity: 0;
    transform: translate(-50%, -50%) scale(1);
  }
}

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

@keyframes heartPulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.3); }
}

.shake {
  animation: screenShake 0.4s ease;
}

.heart-damage {
  animation: heartPulse 0.3s ease;
}

/* ===== Responsive ===== */
@media (max-width: 600px) {
  .menu-container {
    padding: 28px 24px;
  }

  .game-title {
    font-size: 2.2rem;
  }

  .grade-buttons {
    grid-template-columns: repeat(3, 1fr);
    gap: 6px;
  }

  .grade-btn {
    padding: 8px;
    font-size: 0.8rem;
  }

  #game-hud {
    gap: 16px;
    padding: 8px 12px;
  }

  .hud-value {
    font-size: 1.2rem;
  }

  .falling-word {
    font-size: 1.1rem;
    padding: 6px 14px;
  }

  #game-input {
    font-size: 1.1rem;
    padding: 12px 16px;
  }
}