/* ============================================
   Six Little Ducks - 合唱页面样式系统
   更丰富的动画 + SVG鸭子角色 + 舞台灯光效果
   ============================================ */

/* --- Google Fonts --- */
@import url('https://fonts.googleapis.com/css2?family=Poppins:wght@400;600;700;800;900&display=swap');

/* --- CSS 变量 --- */
:root {
  --bg-primary: #0a0a1a;
  --bg-secondary: #12122a;
  --bg-card: rgba(255, 255, 255, 0.06);
  --bg-card-hover: rgba(255, 255, 255, 0.12);

  --text-primary: #ffffff;
  --text-secondary: rgba(255, 255, 255, 0.7);
  --text-muted: rgba(255, 255, 255, 0.35);

  --duck1: #FF6B6B;
  --duck2: #4ECDC4;
  --duck3: #45B7D1;
  --duck4: #96CEB4;
  --duck5: #FFEAA7;
  --duck6: #DDA0DD;
  --all-ducks: linear-gradient(90deg, #FF6B6B, #4ECDC4, #45B7D1, #96CEB4, #FFEAA7, #DDA0DD);

  --transition-fast: 0.2s ease;
  --transition-normal: 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

/* --- 基础重置 --- */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

html, body {
  width: 100%; height: 100%; overflow: hidden;
  font-family: 'Poppins', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  -webkit-font-smoothing: antialiased;
}

/* ============================================
   加载动画
   ============================================ */
.loading-overlay {
  position: fixed; inset: 0;
  background: var(--bg-primary);
  display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  z-index: 9999;
  transition: opacity 0.6s ease;
}
.loading-overlay.hidden { opacity: 0; pointer-events: none; }

.loading-ducks { display: flex; gap: 12px; margin-bottom: 20px; }
.loading-duck {
  font-size: 2.5rem;
  animation: loadBounce 1.2s ease-in-out infinite;
  animation-delay: var(--delay);
  filter: drop-shadow(0 0 8px var(--duck-color));
}
.loading-progress-container {
  width: 280px; max-width: 80vw;
  margin-bottom: 16px;
}
.loading-progress-bar {
  width: 100%; height: 6px;
  background: rgba(255,255,255,0.08);
  border-radius: 3px; overflow: hidden;
}
.loading-progress-fill {
  height: 100%; width: 0%;
  background: var(--all-ducks); background-size: 300% 100%;
  animation: progressGlow 3s linear infinite;
  border-radius: 3px;
  transition: width 0.3s ease;
}
.loading-progress-text {
  font-size: 0.8rem; color: var(--text-secondary);
  text-align: center; margin-top: 8px;
  font-variant-numeric: tabular-nums;
}
.loading-text {
  font-size: 0.9rem; color: var(--text-muted);
  animation: pulse 1.5s ease-in-out infinite;
}
@keyframes loadBounce {
  0%, 100% { transform: translateY(0) scale(1); }
  50% { transform: translateY(-25px) scale(1.1); }
}
@keyframes pulse { 0%, 100% { opacity: 0.4; } 50% { opacity: 1; } }

/* ============================================
   模式选择界面
   ============================================ */
#mode-selector {
  display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  height: 100vh; padding: 2rem;
  background: radial-gradient(ellipse at 50% 30%, #1a1a3e 0%, #0a0a1a 70%);
  position: relative; overflow: hidden;
}

/* 背景气泡装饰 */
.bg-bubbles { position: absolute; inset: 0; pointer-events: none; overflow: hidden; z-index: 0; }
.bubble {
  position: absolute; border-radius: 50%;
  opacity: 0.15; animation: floatBubble var(--duration) ease-in-out infinite;
  animation-delay: var(--delay);
}
@keyframes floatBubble {
  0%, 100% { transform: translateY(0) scale(1); }
  50% { transform: translateY(var(--float-y, -30px)) scale(1.1); }
}

/* 标题区 */
.title-area { text-align: center; margin-bottom: 2.5rem; z-index: 1; position: relative; }

.title-ducks-container {
  display: flex; gap: 8px; justify-content: center;
  margin-bottom: 16px; perspective: 800px;
}
.title-duck-wrapper {
  animation: duckParade 3s ease-in-out infinite;
  transition: transform 0.3s;
  cursor: default;
}
.title-duck-wrapper:hover { transform: scale(1.2) rotate(10deg); }
.title-duck-wrapper:nth-child(1) { animation-delay: 0s; }
.title-duck-wrapper:nth-child(2) { animation-delay: 0.2s; }
.title-duck-wrapper:nth-child(3) { animation-delay: 0.4s; }
.title-duck-wrapper:nth-child(4) { animation-delay: 0.6s; }
.title-duck-wrapper:nth-child(5) { animation-delay: 0.8s; }
.title-duck-wrapper:nth-child(6) { animation-delay: 1.0s; }

@keyframes duckParade {
  0%, 100% { transform: translateY(0) rotate(0deg); }
  25% { transform: translateY(-8px) rotate(-5deg); }
  75% { transform: translateY(-8px) rotate(5deg); }
}

.main-title {
  font-size: 3.8rem; font-weight: 900;
  background: var(--all-ducks); background-size: 200% auto;
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent;
  animation: gradientShift 4s ease-in-out infinite;
  letter-spacing: -0.02em;
}
@keyframes gradientShift {
  0% { background-position: 0% center; }
  50% { background-position: 100% center; }
  100% { background-position: 0% center; }
}

.subtitle {
  font-size: 1.1rem; color: var(--text-secondary);
  letter-spacing: 0.15em; margin-top: 6px;
}

/* 模式卡片 */
.mode-cards { display: flex; gap: 24px; margin-bottom: 2.5rem; z-index: 1; }

.mode-card {
  width: 300px; padding: 32px 28px;
  border-radius: 24px; background: var(--bg-card);
  border: 1px solid rgba(255,255,255,0.08);
  cursor: pointer; text-align: center;
  transition: all var(--transition-normal);
  position: relative; overflow: hidden;
}
.mode-card .card-glow {
  position: absolute; inset: 0; border-radius: 24px;
  opacity: 0; transition: opacity 0.4s;
}
.mode-card.performance .card-glow {
  background: radial-gradient(circle at 50% 0%, rgba(255,107,107,0.15), transparent 70%);
}
.mode-card.practice .card-glow {
  background: radial-gradient(circle at 50% 0%, rgba(78,205,196,0.15), transparent 70%);
}
.mode-card:hover .card-glow { opacity: 1; }
.mode-card:hover {
  transform: translateY(-10px) scale(1.02);
  border-color: rgba(255,255,255,0.2);
  box-shadow: 0 25px 80px rgba(0,0,0,0.5);
}

.card-icon { font-size: 3.5rem; margin-bottom: 12px; }
.mode-card h2 { font-size: 1.5rem; font-weight: 800; margin-bottom: 8px; }
.mode-card p { font-size: 0.9rem; color: var(--text-secondary); line-height: 1.6; }
.card-arrow {
  position: absolute; right: 20px; top: 50%; transform: translateY(-50%);
  font-size: 1.5rem; color: rgba(255,255,255,0.15);
  transition: all 0.3s;
}
.mode-card:hover .card-arrow { color: rgba(255,255,255,0.5); right: 14px; }

/* 角色选择区 */
.role-selector { text-align: center; z-index: 1; }
.role-selector h3 {
  font-size: 1rem; color: var(--text-secondary);
  margin-bottom: 16px; font-weight: 600;
}

.role-buttons { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }

.role-btn {
  width: 80px; height: 96px; border-radius: 16px;
  border: 2px solid transparent;
  background: var(--bg-card);
  cursor: pointer;
  display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  gap: 4px;
  transition: all var(--transition-normal);
  position: relative; overflow: hidden;
  padding: 8px 4px;
}
.role-btn .duck-avatar { transition: transform 0.3s; }
.role-btn .role-label {
  font-size: 0.65rem; font-weight: 600;
  color: var(--text-muted);
  transition: color 0.3s;
}
.role-btn:hover {
  transform: translateY(-5px);
  background: rgba(255,255,255,0.1);
}
.role-btn:hover .duck-avatar { transform: scale(1.15) rotate(5deg); }
.role-btn.active {
  border-color: var(--btn-color);
  box-shadow: 0 0 25px color-mix(in srgb, var(--btn-color) 40%, transparent);
  background: color-mix(in srgb, var(--btn-color) 10%, transparent);
}
.role-btn.active .role-label { color: var(--btn-color); }
.role-btn.active .duck-avatar { animation: selectedDuckBounce 0.8s ease-in-out infinite; }
@keyframes selectedDuckBounce {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-6px); }
}

/* ============================================
   表演模式（与练习模式同布局）
   ============================================ */
#performance-mode {
  display: none; width: 100vw; height: 100vh;
  background: var(--bg-primary);
}
#performance-mode.active { display: flex; flex-direction: column; }

/* 表演模式工具栏 - 复用练习模式样式 */
.perf-toolbar {
  display: flex; align-items: center;
  padding: 10px 18px;
  background: var(--bg-secondary);
  border-bottom: 1px solid rgba(255,255,255,0.06);
  gap: 12px; flex-shrink: 0;
}
.perf-toolbar .toolbar-title { font-size: 1rem; font-weight: 700; flex: 1; }

/* 表演模式主内容 - 复用练习模式flex布局 */
.perf-main-content { display: flex; flex: 1; overflow: hidden; }

/* 表演模式视频面板使用紫色边框区分 */
.perf-video-panel {
  border-right: 2px solid rgba(255,107,107,0.15);
}
@keyframes noteFloat {
  0% { transform: translateY(0) scale(1); opacity: 0.8; }
  100% { transform: translateY(-20px) scale(0.5); opacity: 0; }
}

/* 进度条 */
.progress-bar-container {
  width: 100%; height: 6px;
  background: rgba(255,255,255,0.08);
  border-radius: 3px; cursor: pointer;
  position: relative; margin-bottom: 12px;
  transition: height 0.2s;
}
.progress-bar-container:hover { height: 10px; }
.progress-bar-fill {
  height: 100%; border-radius: 3px;
  background: var(--all-ducks); background-size: 300% 100%;
  animation: progressGlow 4s linear infinite;
  transition: width 0.1s linear; width: 0%;
}
.progress-bar-thumb {
  position: absolute; top: 50%; right: 0;
  width: 14px; height: 14px;
  background: white; border-radius: 50%;
  transform: translate(50%, -50%) scale(0);
  transition: transform 0.2s;
  box-shadow: 0 0 10px rgba(255,255,255,0.4);
}
.progress-bar-container:hover .progress-bar-thumb { transform: translate(50%, -50%) scale(1); }
@keyframes progressGlow {
  0% { background-position: 0% 50%; }
  100% { background-position: 300% 50%; }
}

/* 控制按钮 */
.control-buttons {
  display: flex; justify-content: center;
  align-items: center; gap: 16px;
}
.ctrl-btn {
  background: rgba(255,255,255,0.08); border: none;
  color: white; width: 44px; height: 44px;
  border-radius: 50%; cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  transition: all var(--transition-fast);
}
.ctrl-btn:hover {
  background: rgba(255,255,255,0.18);
  transform: scale(1.1);
}
.ctrl-btn.play-btn {
  width: 60px; height: 60px;
  background: rgba(255,255,255,0.12);
  box-shadow: 0 0 20px rgba(255,255,255,0.05);
}
.ctrl-btn.play-btn:hover { box-shadow: 0 0 30px rgba(255,255,255,0.1); }

.time-display {
  font-size: 0.85rem; color: var(--text-muted);
  font-variant-numeric: tabular-nums;
  min-width: 100px; text-align: center;
}

/* ============================================
   练习模式
   ============================================ */
#practice-mode {
  display: none; width: 100vw; height: 100vh;
  background: var(--bg-primary);
}
#practice-mode.active { display: flex; flex-direction: column; }

/* 工具栏 */
.practice-toolbar {
  display: flex; align-items: center;
  padding: 10px 18px;
  background: var(--bg-secondary);
  border-bottom: 1px solid rgba(255,255,255,0.06);
  gap: 12px; flex-shrink: 0;
}
.toolbar-btn {
  background: rgba(255,255,255,0.06); border: none;
  color: var(--text-secondary); cursor: pointer;
  width: 36px; height: 36px; border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  transition: all var(--transition-fast);
}
.toolbar-btn:hover { background: rgba(255,255,255,0.12); color: white; }
.toolbar-title { font-size: 1rem; font-weight: 700; flex: 1; }

.toolbar-role-picker {
  display: flex; gap: 6px; align-items: center;
}
.toolbar-role-dot {
  width: 24px; height: 24px; border-radius: 50%;
  cursor: pointer; transition: all 0.2s;
  display: flex; align-items: center; justify-content: center;
  font-size: 12px; border: 2px solid transparent;
  opacity: 0.5;
}
.toolbar-role-dot:hover { opacity: 0.8; transform: scale(1.15); }
.toolbar-role-dot.active {
  opacity: 1; border-color: currentColor;
  box-shadow: 0 0 12px currentColor;
  transform: scale(1.15);
}

.toolbar-switch {
  width: auto; padding: 0 14px;
  font-size: 0.8rem; font-weight: 600;
  white-space: nowrap;
}

/* 练习主内容 */
.practice-content { display: flex; flex: 1; overflow: hidden; }

/* 视频区 */
.video-panel {
  width: 60%; display: flex; flex-direction: column;
  background: #000; position: relative;
}
.video-panel video {
  width: 100%; flex: 1;
  object-fit: contain; background: #000;
}
.video-controls {
  padding: 10px 16px;
  background: var(--bg-secondary);
  display: flex; flex-direction: column; gap: 8px;
}
.video-controls .progress-bar-container { margin-bottom: 0; }
.video-controls .control-row {
  display: flex; align-items: center; justify-content: center; gap: 12px;
}
.video-controls .ctrl-btn { width: 38px; height: 38px; }
.video-controls .ctrl-btn.play-btn { width: 48px; height: 48px; }

/* 练习模式鸭子条 */
.prac-duck-strip {
  display: flex; justify-content: center; gap: 12px;
  padding: 8px 16px;
  background: rgba(18,18,42,0.9);
  height: 52px; align-items: center;
}
.prac-duck-mini {
  opacity: 0.3; transition: all 0.35s;
  position: relative;
}
.prac-duck-mini.singing {
  opacity: 1;
  animation: miniDuckBounce 0.4s ease-in-out infinite alternate;
}
.prac-duck-mini.singing::before {
  content: '♪'; position: absolute; top: -8px; right: -4px;
  font-size: 10px; color: var(--mini-color);
  animation: noteFloat 0.8s ease infinite;
}
@keyframes miniDuckBounce {
  0% { transform: translateY(0); }
  100% { transform: translateY(-5px); }
}

/* 右侧面板（上下分区：编排+歌词） */
.right-panel-container {
  width: 40%; display: flex; flex-direction: column;
  background: var(--bg-secondary);
  border-left: 1px solid rgba(255,255,255,0.06);
  overflow: hidden;
}

/* 上部：编排区域（固定高度，不可滚动） */
.choreo-section {
  flex-shrink: 0;
  display: flex; flex-direction: column;
  max-height: 45%;
  overflow-y: auto;
}
.choreo-section::-webkit-scrollbar { width: 3px; }
.choreo-section::-webkit-scrollbar-thumb {
  background: rgba(255,255,255,0.1); border-radius: 2px;
}

/* 表演模式：歌词+队形同时显示布局 */
.perf-lyrics-section {
  flex: 1; display: flex; flex-direction: column;
  overflow: hidden; min-height: 0;
}
.perf-formation-section {
  flex-shrink: 0;
  display: flex; flex-direction: column;
  max-height: 45%;
  overflow-y: auto;
}
.perf-formation-section::-webkit-scrollbar { width: 3px; }
.perf-formation-section::-webkit-scrollbar-thumb {
  background: rgba(255,255,255,0.1); border-radius: 2px;
}
/* 表演模式队形面板加大 */
.perf-formation-stage-large {
  max-height: 200px;
  min-height: 120px;
}
/* 队形中使用SVG鸭子 */
.formation-duck-svg {
  position: absolute;
  width: 48px; height: 48px;
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  transition: all 0.8s cubic-bezier(0.4, 0, 0.2, 1);
  z-index: 2;
  cursor: default;
  filter: drop-shadow(0 2px 4px rgba(0,0,0,0.3));
}
.formation-duck-svg .duck-svg-wrap {
  width: 40px; height: 40px;
  display: flex; align-items: center; justify-content: center;
  transition: all 0.4s ease;
  position: relative;
}
.formation-duck-svg .duck-svg-wrap svg {
  width: 40px; height: 40px;
}
.formation-duck-svg .duck-label {
  position: absolute;
  bottom: -16px; left: 50%;
  transform: translateX(-50%);
  font-size: 0.55rem; color: var(--text-muted);
  white-space: nowrap; font-weight: 600;
  text-shadow: 0 1px 4px rgba(0,0,0,0.8);
}
.formation-duck-svg.singing .duck-svg-wrap {
  transform: scale(1.25);
  filter: drop-shadow(0 0 12px currentColor);
}
.formation-duck-svg.singing .duck-svg-wrap::before {
  content: '♪'; position: absolute; top: -10px; right: -8px;
  font-size: 12px; color: currentColor;
  animation: noteFloat 0.8s ease infinite;
}
.formation-duck-svg.my-duck .duck-svg-wrap {
  outline: 2px solid white;
  outline-offset: 3px;
  border-radius: 50%;
}

/* 分隔线 */
.panel-divider {
  height: 1px; flex-shrink: 0;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.12), transparent);
  margin: 0 16px;
}

/* 下部：歌词区域（flex:1 填充剩余空间） */
.lyrics-section {
  flex: 1; display: flex; flex-direction: column;
  overflow: hidden; min-height: 0;
}
.lyrics-panel-header {
  padding: 12px 16px;
  border-bottom: 1px solid rgba(255,255,255,0.06);
  font-weight: 700; font-size: 0.95rem;
  color: var(--text-secondary);
  display: flex; justify-content: space-between; align-items: center;
}
.lyrics-section-tag {
  font-size: 0.75rem; padding: 2px 10px;
  border-radius: 10px; background: rgba(255,255,255,0.06);
  color: var(--text-muted);
}

.lyrics-scroll-container {
  flex: 1; overflow-y: auto; padding: 20px 16px;
  scroll-behavior: smooth;
  /* 确保歌词可以滚动到底部，添加底部内边距 */
  padding-bottom: 50%;
}
.lyrics-scroll-container::-webkit-scrollbar { width: 4px; }
.lyrics-scroll-container::-webkit-scrollbar-thumb {
  background: rgba(255,255,255,0.15); border-radius: 2px;
}

/* 练习模式歌词行 */
.practice-lyric-line {
  display: flex; align-items: center;
  padding: 10px 12px; margin-bottom: 4px;
  border-radius: 12px;
  transition: all var(--transition-normal);
  cursor: pointer; position: relative;
  border: 1px solid transparent;
}
.practice-lyric-line:hover { background: rgba(255,255,255,0.04); }

.lyric-role-indicator {
  width: 28px; height: 28px; border-radius: 8px;
  margin-right: 10px; flex-shrink: 0;
  display: flex; align-items: center; justify-content: center;
  font-size: 14px; transition: all var(--transition-normal);
  background: rgba(255,255,255,0.04);
}
.lyric-text {
  font-size: 1rem; line-height: 1.6;
  color: var(--text-secondary);
  transition: all var(--transition-normal);
  flex: 1;
}
.singer-tags {
  display: flex; gap: 4px; margin-left: 8px; flex-shrink: 0;
}
.singer-tag {
  font-size: 0.6rem; padding: 2px 6px;
  border-radius: 6px;
  background: rgba(255,255,255,0.05);
  color: var(--text-muted); white-space: nowrap;
  font-weight: 600;
}

/* 歌词行状态 - 当前播放行高亮 */
.practice-lyric-line.active {
  background: rgba(255,255,255,0.10);
  border-color: rgba(255,215,0,0.35);
  transform: scale(1.02);
  box-shadow: 0 0 16px rgba(255,215,0,0.08), inset 0 0 0 1px rgba(255,215,0,0.12);
  position: relative;
}
.practice-lyric-line.active::before {
  content: '';
  position: absolute; left: 0; top: 0; bottom: 0;
  width: 3px; border-radius: 3px 0 0 3px;
  background: linear-gradient(180deg, #FFD700, #FFA502);
  box-shadow: 0 0 8px rgba(255,215,0,0.5);
}
.practice-lyric-line.active .lyric-text {
  color: #fff; font-weight: 700; font-size: 1.1rem;
  text-shadow: 0 0 10px rgba(255,255,255,0.15);
}
.practice-lyric-line.active .lyric-role-indicator {
  transform: scale(1.2);
  box-shadow: 0 0 14px var(--indicator-color, rgba(255,215,0,0.3));
}
.practice-lyric-line.active .singer-tag {
  opacity: 1; font-weight: 700;
}
.practice-lyric-line.past .lyric-text { color: var(--text-muted); }
.practice-lyric-line.past .lyric-role-indicator { opacity: 0.4; }

/* 我的角色 */
.practice-lyric-line.my-role {
  border-color: rgba(255,255,255,0.1);
  background: rgba(255,255,255,0.03);
}
.practice-lyric-line.my-role .lyric-text { font-weight: 600; }
.practice-lyric-line.my-role.active {
  border-color: var(--my-role-color, rgba(255,255,255,0.3));
  box-shadow: 0 0 20px color-mix(in srgb, var(--my-role-color, white) 15%, transparent);
}

/* ============================================
   动作编排区域
   ============================================ */
.choreo-panel-header {
  padding: 10px 16px;
  border-bottom: 1px solid rgba(255,255,255,0.06);
  font-weight: 700; font-size: 0.85rem;
  color: var(--text-secondary);
  display: flex; justify-content: space-between; align-items: center;
  flex-shrink: 0;
}
.choreo-section-tag {
  font-size: 0.75rem; padding: 2px 10px;
  border-radius: 10px; background: rgba(255,255,255,0.06);
  color: var(--text-muted);
}

/* 当前动作卡片 */
.current-action-card {
  margin: 8px 16px;
  padding: 12px 16px;
  border-radius: 12px;
  background: linear-gradient(135deg, rgba(78,205,196,0.1) 0%, rgba(69,183,209,0.1) 100%);
  border: 1px solid rgba(78,205,196,0.2);
  position: relative;
  overflow: hidden;
  flex-shrink: 0;
  transition: all 0.4s ease;
}
.current-action-card::before {
  content: '';
  position: absolute; left: 0; top: 0; bottom: 0;
  width: 4px; border-radius: 4px 0 0 4px;
  background: linear-gradient(180deg, var(--duck2), var(--duck3));
}
.current-action-card.action-pulse {
  animation: actionPulse 0.6s ease;
}
@keyframes actionPulse {
  0% { transform: scale(1); }
  50% { transform: scale(1.02); border-color: rgba(78,205,196,0.5); }
  100% { transform: scale(1); }
}
.action-label {
  font-size: 0.7rem; font-weight: 700;
  color: var(--duck2); text-transform: uppercase;
  letter-spacing: 0.1em; margin-bottom: 6px;
}
.action-text {
  font-size: 1.1rem; font-weight: 600;
  color: var(--text-primary); line-height: 1.5;
}

/* ============================================
   队形可视化
   ============================================ */
.formation-area {
  margin: 0 16px 12px;
  flex-shrink: 0;
}
.formation-header {
  display: flex; justify-content: space-between; align-items: center;
  margin-bottom: 8px;
}
.formation-title {
  font-size: 0.8rem; font-weight: 700;
  color: var(--text-secondary);
}
.formation-desc {
  font-size: 0.7rem; color: var(--text-muted);
  padding: 2px 8px; border-radius: 8px;
  background: rgba(255,255,255,0.05);
}

.formation-stage {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  max-height: 160px;
  border-radius: 12px;
  background: linear-gradient(180deg, rgba(10,10,26,0.9) 0%, rgba(26,26,62,0.6) 100%);
  border: 1px solid rgba(255,255,255,0.08);
  overflow: hidden;
}
.formation-stage::before {
  content: '';
  position: absolute; bottom: 0; left: 0; right: 0;
  height: 3px;
  background: linear-gradient(90deg, transparent, rgba(255,215,0,0.4), transparent);
}

.stage-label {
  position: absolute;
  font-size: 0.55rem; color: rgba(255,255,255,0.2);
  font-weight: 600; letter-spacing: 0.15em;
  text-transform: uppercase;
}
.stage-label-front {
  bottom: 6px; left: 50%;
  transform: translateX(-50%);
}
.stage-label-back {
  top: 6px; left: 50%;
  transform: translateX(-50%);
}

/* 队形中的鸭子点 */
.formation-duck {
  position: absolute;
  width: 36px; height: 36px;
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  transition: all 0.8s cubic-bezier(0.4, 0, 0.2, 1);
  z-index: 2;
  cursor: default;
}
.formation-duck .duck-dot {
  width: 28px; height: 28px;
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: 0.55rem; font-weight: 700;
  color: rgba(0,0,0,0.7);
  box-shadow: 0 2px 10px rgba(0,0,0,0.3);
  transition: all 0.4s ease;
  position: relative;
}
.formation-duck .duck-dot::after {
  content: attr(data-label);
  position: absolute;
  bottom: -14px; left: 50%;
  transform: translateX(-50%);
  font-size: 0.5rem; color: var(--text-muted);
  white-space: nowrap;
}
.formation-duck.singing .duck-dot {
  transform: scale(1.3);
  box-shadow: 0 0 20px currentColor;
}
.formation-duck.singing .duck-dot::before {
  content: '♪'; position: absolute; top: -12px; right: -6px;
  font-size: 10px; color: currentColor;
  animation: noteFloat 0.8s ease infinite;
}
.formation-duck.my-duck .duck-dot {
  outline: 2px solid white;
  outline-offset: 2px;
}

/* 队形连线 (可选) */
.formation-line {
  position: absolute;
  background: rgba(255,255,255,0.08);
  height: 1px;
  transform-origin: left center;
  z-index: 1;
  transition: all 0.8s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ============================================
   AB段循环控件
   ============================================ */
.ab-loop-range {
  position: absolute; top: 0; height: 100%;
  background: rgba(78,205,196,0.2);
  border-left: 2px solid var(--duck2);
  border-right: 2px solid var(--duck2);
  border-radius: 2px;
  pointer-events: none;
  display: none;
  z-index: 1;
}
.ab-loop-range.visible { display: block; }

#prac-set-a-btn, #prac-set-b-btn {
  width: 32px; height: 32px;
  font-size: 11px;
}
#prac-set-a-btn.active-point { 
  background: rgba(78,205,196,0.3); 
  color: var(--duck2);
  box-shadow: 0 0 8px rgba(78,205,196,0.3);
}
#prac-set-b-btn.active-point { 
  background: rgba(78,205,196,0.3); 
  color: var(--duck2);
  box-shadow: 0 0 8px rgba(78,205,196,0.3);
}
#prac-clear-ab-btn {
  width: auto; padding: 0 8px; height: 32px;
}

/* ============================================
   全屏（含webkit前缀）
   ============================================ */
:fullscreen #performance-mode,
:-webkit-full-screen #performance-mode,
:-moz-full-screen #performance-mode,
:-ms-fullscreen #performance-mode {
  background: var(--bg-primary);
}

/* ============================================
   安全区域（iPhone刘海屏适配）
   ============================================ */
body {
  padding-top: env(safe-area-inset-top);
  padding-bottom: env(safe-area-inset-bottom);
  padding-left: env(safe-area-inset-left);
  padding-right: env(safe-area-inset-right);
}

/* ============================================
   触摸设备优化
   ============================================ */
@media (hover: none) and (pointer: coarse) {
  .ctrl-btn { width: 48px; height: 48px; min-width: 48px; }
  .ctrl-btn.play-btn { width: 56px; height: 56px; }
  .toolbar-role-dot { width: 32px; height: 32px; }
  .progress-bar-container { height: 10px; }
  .progress-bar-thumb { width: 18px; height: 18px; transform: translate(50%, -50%) scale(1) !important; }
  .mode-card:hover { transform: none; }
  .mode-card:active { transform: scale(0.98); }
}

/* ============================================
   响应式 - PC大屏 (≥1920px)
   ============================================ */
@media (min-width: 1920px) {
  .perf-duck-char svg { width: 70px; height: 70px; }
  .practice-lyric-line.active .lyric-text { font-size: 1.25rem; }
}

/* ============================================
   响应式 - iPad横屏 (1024-1199px)
   ============================================ */
@media (min-width: 768px) and (max-width: 1199px) {
  .video-panel { width: 55%; }
  .right-panel-container { width: 45%; }
  .main-title { font-size: 3rem; }
  .mode-card { width: 260px; padding: 24px 20px; }
  .role-btn { width: 68px; height: 82px; }
}

/* ============================================
   响应式 - iPad竖屏 & 小平板 (768-1023px)
   ============================================ */
@media (max-width: 1023px) and (min-width: 768px) {
  .main-title { font-size: 2.8rem; }
  .mode-cards { gap: 16px; }
  .mode-card { width: 240px; padding: 24px 18px; }
  .practice-content, .perf-main-content { flex-direction: column; }
  .video-panel { width: 100%; height: 45%; }
  .right-panel-container { width: 100%; height: 55%; border-left: none; border-top: 1px solid rgba(255,255,255,0.06); }
  .choreo-section { max-height: 35%; }
  .formation-stage { max-height: 130px; }
}

/* ============================================
   响应式 - 手机 (≤767px)
   ============================================ */
@media (max-width: 767px) {
  .main-title { font-size: 2rem; }
  .subtitle { font-size: 0.9rem; }
  .mode-cards { flex-direction: column; align-items: center; gap: 14px; }
  .mode-card { width: 100%; max-width: 340px; padding: 22px 18px; }
  .mode-card h2 { font-size: 1.2rem; }
  .card-icon { font-size: 2.8rem; }

  .role-selector h3 { font-size: 0.9rem; }
  .role-buttons { gap: 8px; }
  .role-btn { width: 56px; height: 68px; border-radius: 12px; }
  .role-btn .role-label { font-size: 0.55rem; }

  .practice-content, .perf-main-content { flex-direction: column; }
  .video-panel { width: 100%; height: 40%; min-height: 180px; }
  .right-panel-container { width: 100%; flex: 1; border-left: none; border-top: 1px solid rgba(255,255,255,0.06); }
  .choreo-section { max-height: 30%; }
  .formation-stage { max-height: 100px; }

  .toolbar-title { font-size: 0.85rem; }
  .toolbar-switch { font-size: 0.7rem; padding: 0 10px; }

  .practice-lyric-line { padding: 8px 10px; }
  .lyric-role-indicator { width: 24px; height: 24px; margin-right: 8px; }
  .lyric-text { font-size: 0.9rem; }
  .practice-lyric-line.active .lyric-text { font-size: 1rem; }
  .singer-tags { display: none; } /* 手机屏幕太小，隐藏角色标签 */

  .video-controls .ctrl-btn { width: 36px; height: 36px; }
  .video-controls .ctrl-btn.play-btn { width: 44px; height: 44px; }
  .time-display { font-size: 0.75rem; min-width: 80px; }

  .prac-duck-strip { gap: 6px; padding: 6px 8px; height: 44px; }

  .toolbar-role-picker { gap: 4px; }
  .toolbar-role-dot { width: 22px; height: 22px; font-size: 8px; }

  /* 隐藏编排面板在手机上 - 太小了 */
  .choreo-section, #perf-choreo-panel-view, .perf-formation-section { display: none !important; }
  .panel-divider { display: none; }
  .lyrics-section, #perf-lyrics-panel-view, .perf-lyrics-section { flex: 1; }
  .toolbar-view-tabs { display: none; }
}

/* ============================================
   响应式 - 小手机 (≤375px, iPhone SE等)
   ============================================ */
@media (max-width: 375px) {
  .main-title { font-size: 1.7rem; }
  .title-ducks-container { gap: 4px; }
  .mode-card { padding: 16px 14px; }
  .role-btn { width: 48px; height: 60px; }
  .video-panel { min-height: 160px; }
}

/* ============================================
   横屏模式优化
   ============================================ */
@media (orientation: landscape) and (max-height: 500px) {
  /* 手机横屏 */
  .practice-content, .perf-main-content { flex-direction: row; }
  .video-panel { width: 55%; height: 100%; }
  .right-panel-container { width: 45%; height: 100%; border-top: none; border-left: 1px solid rgba(255,255,255,0.06); }
  .prac-duck-strip { height: 40px; padding: 4px 8px; }
  .video-controls { padding: 6px 12px; }
  .lyrics-panel-header { padding: 8px 12px; }
  .choreo-section, #perf-choreo-panel-view, .perf-formation-section { display: none !important; }
  .panel-divider { display: none; }
}

/* ============================================
   隐藏
   ============================================ */
audio { display: none; }

/* ============================================
   过渡动画
   ============================================ */
.fade-in { animation: fadeIn 0.5s ease forwards; }
@keyframes fadeIn { from { opacity: 0; transform: translateY(20px); } to { opacity: 1; transform: translateY(0); } }
.fade-out { animation: fadeOut 0.3s ease forwards; }
@keyframes fadeOut { from { opacity: 1; } to { opacity: 0; } }