/* ─── CSS Variables ──────────────────────────────────────── */
:root {
  --coral:     #FF6B6B;
  --coral-dk:  #E85555;
  --teal:      #2DD4BF;
  --teal-dk:   #0D9488;
  --violet:    #A78BFA;
  --violet-dk: #7C3AED;
  --gold:      #FBBF24;
  --gold-dk:   #D97706;
  --cream:     #FFFBF0;
  --cream2:    #FFF3D0;
  --text:      #2D2D2D;
  --text-soft: #7C7C7C;
  --white:     #FFFFFF;
  --shadow-sm: 0 4px 12px rgba(0,0,0,0.10);
  --shadow-md: 0 8px 28px rgba(0,0,0,0.14);
  --shadow-lg: 0 16px 48px rgba(0,0,0,0.18);
  --radius-sm: 14px;
  --radius-md: 22px;
  --radius-lg: 30px;
}

/* ─── Reset ──────────────────────────────────────────────── */
* { margin: 0; padding: 0; box-sizing: border-box; }

/* ─── Body & Background ──────────────────────────────────── */
body {
  font-family: 'Fredoka', 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  background-color: var(--cream);
  background-image:
    radial-gradient(circle at 10% 15%, rgba(255,107,107,0.18) 0%, transparent 35%),
    radial-gradient(circle at 88% 10%, rgba(45,212,191,0.18) 0%, transparent 35%),
    radial-gradient(circle at 80% 85%, rgba(167,139,250,0.15) 0%, transparent 35%),
    radial-gradient(circle at 15% 80%, rgba(251,191,36,0.18) 0%, transparent 35%);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  overflow-x: hidden;
}

/* ─── Header ─────────────────────────────────────────────── */
.header {
  width: 100%;
  background: var(--white);
  padding: 18px 28px;
  padding-top: calc(18px + env(safe-area-inset-top));
  display: flex;
  justify-content: space-between;
  align-items: center;
  box-shadow: 0 4px 20px rgba(0,0,0,0.08);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header h1 {
  color: var(--text);
  font-size: 1.7rem;
  font-weight: 600;
  letter-spacing: 0.02em;
}

.stars-display {
  background: linear-gradient(135deg, var(--gold), var(--gold-dk));
  border-radius: 50px;
  padding: 8px 20px;
  color: var(--white);
  font-size: 1.15rem;
  font-weight: 600;
  box-shadow: 0 4px 12px rgba(251,191,36,0.45);
}

/* ─── Container ──────────────────────────────────────────── */
.container {
  width: 100%;
  max-width: 820px;
  padding: 28px 20px 40px;
  flex: 1;
}

/* ─── Screen ─────────────────────────────────────────────── */
.screen       { display: none; }
.screen.active { display: block; }

/* ─── Home Greeting ──────────────────────────────────────── */
.home-greeting {
  text-align: center;
  margin-bottom: 28px;
  color: var(--text);
  font-size: 1.15rem;
  opacity: 0.75;
  font-weight: 400;
}

/* ─── Menu Grid ──────────────────────────────────────────── */
.menu-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
  margin-top: 8px;
}

.menu-btn {
  border: none;
  border-radius: var(--radius-lg);
  padding: 36px 20px 30px;
  cursor: pointer;
  text-align: center;
  transition: transform 0.18s cubic-bezier(.34,1.56,.64,1), box-shadow 0.18s;
  position: relative;
  overflow: hidden;
  color: var(--white);
}

.menu-btn::after {
  content: '';
  position: absolute;
  inset: 0;
  background: rgba(255,255,255,0.12);
  opacity: 0;
  transition: opacity 0.2s;
}

.menu-btn:active {
  transform: scale(0.95) translateY(2px);
  box-shadow: var(--shadow-sm) !important;
}

.menu-btn:hover::after { opacity: 1; }

.menu-btn .icon  { font-size: 3.6rem; display: block; margin-bottom: 14px; filter: drop-shadow(0 3px 6px rgba(0,0,0,0.2)); }
.menu-btn .label { font-size: 1.35rem; font-weight: 600; display: block; letter-spacing: 0.03em; }
.menu-btn .desc  { font-size: 0.88rem; opacity: 0.85; margin-top: 7px; display: block; }

.menu-btn.pinyin {
  background: linear-gradient(145deg, #FF6B6B, #FF8E53);
  box-shadow: 0 10px 30px rgba(255,107,107,0.45);
}
.menu-btn.hanzi {
  background: linear-gradient(145deg, #2DD4BF, #0D9488);
  box-shadow: 0 10px 30px rgba(45,212,191,0.40);
}
.menu-btn.game {
  background: linear-gradient(145deg, #A78BFA, #7C3AED);
  box-shadow: 0 10px 30px rgba(167,139,250,0.40);
}
.menu-btn.review {
  background: linear-gradient(145deg, #FBBF24, #F59E0B);
  box-shadow: 0 10px 30px rgba(251,191,36,0.40);
}

/* ─── Back Button ────────────────────────────────────────── */
.back-btn {
  background: var(--white);
  border: 2px solid #E5E5E5;
  color: var(--text);
  border-radius: var(--radius-sm);
  padding: 10px 20px;
  min-height: 44px;
  font-size: 0.95rem;
  font-family: inherit;
  cursor: pointer;
  margin-bottom: 20px;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  box-shadow: var(--shadow-sm);
  transition: background 0.15s, transform 0.15s;
}
.back-btn:active { transform: scale(0.96); }

/* ─── Section Title ──────────────────────────────────────── */
.section-title {
  color: var(--text);
  font-size: 1.75rem;
  font-weight: 600;
  margin: 4px 0 22px;
  text-align: center;
}

/* ─── Tab Bar ────────────────────────────────────────────── */
.tab-bar {
  display: flex;
  gap: 8px;
  margin-bottom: 22px;
  background: var(--white);
  border-radius: var(--radius-md);
  padding: 6px;
  box-shadow: var(--shadow-sm);
}

.tab-btn {
  flex: 1;
  border: none;
  background: transparent;
  color: var(--text-soft);
  border-radius: var(--radius-sm);
  padding: 11px;
  font-size: 1rem;
  font-family: inherit;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s;
}

.tab-btn.active {
  background: linear-gradient(135deg, var(--violet), var(--violet-dk));
  color: var(--white);
  font-weight: 600;
  box-shadow: 0 4px 12px rgba(124,58,237,0.35);
}

/* ─── Cards Grid ─────────────────────────────────────────── */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
}

.card {
  background: var(--white);
  border-radius: var(--radius-md);
  padding: 18px 10px;
  text-align: center;
  cursor: pointer;
  box-shadow: var(--shadow-sm);
  transition: transform 0.18s cubic-bezier(.34,1.56,.64,1), box-shadow 0.18s;
  min-height: 92px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 6px;
  border-bottom: 4px solid var(--cream2);
}

.card:hover  { transform: translateY(-3px); box-shadow: var(--shadow-md); }
.card:active { transform: scale(0.93); }

.card .letter  { font-size: 1.85rem; font-weight: 700; color: var(--violet-dk); }
.card .example { font-size: 0.95rem; color: var(--text-soft); }

/* ─── Quiz Box ───────────────────────────────────────────── */
.quiz-box {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 32px 28px;
  box-shadow: var(--shadow-md);
  margin-top: 10px;
}

.quiz-question {
  font-size: 3rem;
  text-align: center;
  color: var(--violet-dk);
  margin-bottom: 8px;
  font-weight: 700;
  letter-spacing: 5px;
}

.quiz-hint {
  text-align: center;
  color: var(--text-soft);
  margin-bottom: 26px;
  font-size: 1rem;
}

.options-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.option-btn {
  background: var(--cream);
  border: 3px solid #E8E0FF;
  border-radius: var(--radius-md);
  padding: 22px;
  font-size: 1.65rem;
  font-family: inherit;
  cursor: pointer;
  transition: all 0.18s cubic-bezier(.34,1.56,.64,1);
  font-weight: 600;
  color: var(--text);
}

.option-btn:active  { transform: scale(0.95); }
.option-btn.correct { background: #DCFCE7; border-color: #22C55E; color: #15803D; }
.option-btn.wrong   { background: #FEE2E2; border-color: #EF4444; color: #B91C1C; }

/* ─── Result Popup ───────────────────────────────────────── */
.result-popup {
  text-align: center;
  padding: 20px 0 10px;
}

.result-emoji {
  font-size: 4.5rem;
  display: block;
  margin-bottom: 10px;
  animation: bounceIn 0.4s cubic-bezier(.34,1.56,.64,1);
}

@keyframes bounceIn {
  0%   { transform: scale(0.3); opacity: 0; }
  100% { transform: scale(1);   opacity: 1; }
}

.result-text {
  font-size: 1.4rem;
  font-weight: 600;
  color: var(--text);
}

/* ─── Buttons ────────────────────────────────────────────── */
.next-btn {
  background: linear-gradient(135deg, var(--violet), var(--violet-dk));
  color: var(--white);
  border: none;
  border-radius: var(--radius-md);
  padding: 14px 44px;
  font-size: 1.1rem;
  font-family: inherit;
  font-weight: 600;
  cursor: pointer;
  margin-top: 18px;
  box-shadow: 0 6px 18px rgba(124,58,237,0.40);
  transition: transform 0.15s, box-shadow 0.15s;
}
.next-btn:active { transform: scale(0.96); }

.btn-primary {
  background: linear-gradient(135deg, var(--violet), var(--violet-dk));
  color: var(--white);
  border: none;
  border-radius: var(--radius-md);
  padding: 16px 48px;
  font-size: 1.15rem;
  font-family: inherit;
  font-weight: 600;
  cursor: pointer;
  box-shadow: 0 6px 18px rgba(124,58,237,0.40);
  margin: 6px;
  transition: transform 0.15s;
}
.btn-primary:active { transform: scale(0.96); }

.btn-secondary {
  background: var(--white);
  color: var(--violet-dk);
  border: 2.5px solid var(--violet-dk);
  border-radius: var(--radius-md);
  padding: 14px 32px;
  font-size: 1.05rem;
  font-family: inherit;
  font-weight: 600;
  cursor: pointer;
  margin: 6px;
}

/* ─── Hanzi Card ─────────────────────────────────────────── */
.hanzi-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 34px 28px;
  box-shadow: var(--shadow-md);
  text-align: center;
  margin-top: 10px;
}

.hanzi-big {
  font-size: 6rem;
  line-height: 1.15;
  margin: 10px 0;
  color: var(--text);
}

.hanzi-emoji {
  font-size: 3.2rem;
  display: block;
  margin-bottom: 8px;
}

.hanzi-meaning {
  font-size: 1.2rem;
  color: var(--text-soft);
  margin-bottom: 26px;
}

/* ─── Game Screen ────────────────────────────────────────── */
.game-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 14px;
  color: var(--text);
}

.level-info {
  font-size: 1.1rem;
  font-weight: 600;
  background: var(--white);
  border-radius: var(--radius-sm);
  padding: 6px 14px;
  box-shadow: var(--shadow-sm);
}

.score-info {
  font-size: 1.1rem;
  font-weight: 600;
  background: linear-gradient(135deg, var(--gold), var(--gold-dk));
  color: var(--white);
  border-radius: var(--radius-sm);
  padding: 6px 14px;
  box-shadow: 0 4px 10px rgba(251,191,36,0.35);
}

.progress-bar {
  background: var(--white);
  border-radius: 50px;
  height: 14px;
  margin-bottom: 22px;
  overflow: hidden;
  box-shadow: inset 0 2px 4px rgba(0,0,0,0.08);
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--teal), var(--violet));
  border-radius: 50px;
  transition: width 0.4s cubic-bezier(.34,1.56,.64,1);
}

/* ─── Level Complete ─────────────────────────────────────── */
.level-complete {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 44px 30px;
  text-align: center;
  box-shadow: var(--shadow-lg);
}

.level-complete .big-emoji {
  font-size: 5rem;
  display: block;
  margin-bottom: 16px;
  animation: bounceIn 0.5s cubic-bezier(.34,1.56,.64,1);
}

.level-complete h2 {
  font-size: 2rem;
  font-weight: 700;
  color: var(--violet-dk);
  margin-bottom: 10px;
}

.level-complete p {
  color: var(--text-soft);
  font-size: 1.1rem;
  margin-bottom: 26px;
}

/* ─── Fireworks ──────────────────────────────────────────── */
.firework-container {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 9999;
}

.firework {
  position: absolute;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  animation: explode 1s ease-out forwards;
}

@keyframes explode {
  0%   { transform: scale(0); opacity: 1; }
  100% { transform: scale(20); opacity: 0; }
}

/* ─── Toast ──────────────────────────────────────────────── */
.toast {
  position: fixed;
  bottom: 40px;
  left: 50%;
  transform: translateX(-50%) translateY(80px);
  background: rgba(30,30,30,0.88);
  color: var(--white);
  padding: 13px 28px;
  border-radius: 50px;
  font-size: 1.05rem;
  font-family: inherit;
  z-index: 9998;
  transition: transform 0.3s cubic-bezier(.34,1.56,.64,1);
  white-space: normal;
  max-width: 88vw;
  word-break: break-word;
  text-align: center;
}
.toast.show { transform: translateX(-50%) translateY(0); }

/* ─── Subject Sections (Home Dashboard) ─────────────────── */
.subject-section {
  background: var(--white);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
  margin-bottom: 20px;
}

.subject-header {
  padding: 18px 22px;
  display: flex;
  align-items: center;
  gap: 14px;
  color: var(--white);
  position: relative;
}

.subj-icon { font-size: 2rem; line-height: 1; }
.subj-name { font-size: 1.4rem; font-weight: 700; line-height: 1.2; }
.subj-sub  { font-size: 0.78rem; opacity: 0.8; margin-top: 2px; letter-spacing: 0.05em; }

.subject-header.chinese-hdr { background: linear-gradient(135deg, #6366F1, #4F46E5); }
.subject-header.math-hdr    { background: linear-gradient(135deg, #F97316, #EA580C); }
.subject-header.english-hdr { background: linear-gradient(135deg, #10B981, #059669); }

.subject-header .new-badge {
  position: absolute;
  right: 18px;
  top: 50%;
  transform: translateY(-50%);
  background: rgba(255,255,255,0.25);
  border: 2px solid rgba(255,255,255,0.5);
  color: white;
  font-size: 0.82rem;
  font-weight: 700;
  border-radius: 50px;
  padding: 3px 11px;
}

.subject-modules {
  padding: 16px;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(90px, 1fr));
  gap: 12px;
}

.module-btn {
  background: var(--cream);
  border: none;
  border-radius: 18px;
  padding: 18px 8px 14px;
  cursor: pointer;
  text-align: center;
  font-family: inherit;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 7px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.07);
  transition: transform 0.18s cubic-bezier(.34,1.56,.64,1), background 0.15s;
}

.module-btn:active { transform: scale(0.90); }
.module-btn .m-icon  { font-size: 2.1rem; line-height: 1; }
.module-btn .m-label { font-size: 0.88rem; font-weight: 600; color: var(--text); }

.ch-mod:hover { background: #EEF2FF; }
.mt-mod:hover { background: #FFF7ED; }
.en-mod:hover { background: #ECFDF5; }

/* ─── Stats Footer ───────────────────────────────────────── */
.stats-footer {
  text-align: center;
  padding: 14px;
  color: var(--text-soft);
  font-size: 0.92rem;
  cursor: pointer;
  background: var(--white);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  transition: background 0.15s;
}
.stats-footer:active { background: var(--cream2); }
.stats-footer + .stats-footer { margin-top: 10px; }
.backup-footer { background: #f0f9ff; color: #0369a1; }
.backup-footer:active { background: #e0f2fe; }

/* ─── Math Featured / New Badge (keep for tab override) ──── */
.new-badge {
  background: rgba(255,255,255,0.28);
  border: 2px solid rgba(255,255,255,0.55);
  color: white;
  font-size: 0.85rem;
  font-weight: 700;
  border-radius: 50px;
  padding: 4px 12px;
  letter-spacing: 0.05em;
  flex-shrink: 0;
}

.menu-btn.math {
  background: linear-gradient(145deg, #F97316, #EA580C);
  box-shadow: 0 10px 30px rgba(249,115,22,0.42);
}

/* ─── Math tab active ────────────────────────────────────── */
#math-screen .tab-btn.active {
  background: linear-gradient(135deg, #F97316, #EA580C);
  box-shadow: 0 4px 12px rgba(234,88,12,0.35);
}

/* ─── English tab active ─────────────────────────────────── */
#english-screen .tab-btn.active {
  background: linear-gradient(135deg, #10B981, #059669);
  box-shadow: 0 4px 12px rgba(5,150,105,0.35);
}

/* ─── Math Content Displays ──────────────────────────────── */
.math-number-display {
  font-size: 5rem;
  font-weight: 700;
  text-align: center;
  color: var(--coral);
  letter-spacing: 4px;
  margin-bottom: 8px;
  line-height: 1.1;
}

.math-calc-display {
  font-size: 2.6rem;
  font-weight: 700;
  text-align: center;
  color: var(--text);
  margin-bottom: 10px;
  letter-spacing: 2px;
}

.math-shape-display {
  font-size: 7rem;
  text-align: center;
  margin-bottom: 10px;
  line-height: 1.1;
  color: var(--teal-dk);
}

.math-pattern-seq {
  display: flex;
  justify-content: center;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 12px;
  padding: 16px 0;
}

.pattern-item {
  font-size: 2rem;
  min-width: 44px;
  text-align: center;
  background: var(--cream);
  border-radius: 12px;
  padding: 8px;
}

.pattern-blank {
  background: #E8E0FF;
  color: var(--violet-dk);
  font-weight: 700;
  animation: pulse 1.2s infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50%       { opacity: 0.5; }
}

/* ─── English Content ────────────────────────────────────── */
.eng-alpha-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 28px 24px;
  box-shadow: var(--shadow-md);
  text-align: center;
}

.alpha-letters {
  display: flex;
  justify-content: center;
  align-items: baseline;
  gap: 16px;
  margin-bottom: 20px;
}

.alpha-big   { font-size: 6rem; font-weight: 700; color: #10B981; line-height: 1; }
.alpha-small { font-size: 4rem; font-weight: 700; color: #6EE7B7; line-height: 1; }

.alpha-word-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 14px;
  background: var(--cream);
  border-radius: var(--radius-md);
  padding: 16px 20px;
  margin-bottom: 18px;
  cursor: pointer;
  transition: background 0.15s;
}
.alpha-word-row:active { background: #D1FAE5; }

.alpha-emoji { font-size: 2.5rem; }
.alpha-word  { font-size: 1.8rem; font-weight: 600; color: var(--text); }
.alpha-sound { font-size: 1.4rem; }

.alpha-progress {
  color: var(--text-soft);
  font-size: 0.9rem;
  margin-bottom: 18px;
}

.alpha-nav {
  display: flex;
  justify-content: center;
  gap: 14px;
}

.eng-quiz-display {
  font-size: 4.5rem;
  text-align: center;
  margin-bottom: 8px;
  line-height: 1.2;
}

.eng-opt { font-size: 1.2rem !important; letter-spacing: 0.02em; }

/* ─── Words Menu ─────────────────────────────────────────── */
.words-menu {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 28px 20px;
  box-shadow: var(--shadow-md);
  text-align: center;
}

.words-menu-title {
  font-size: 1.2rem;
  color: var(--text-soft);
  margin-bottom: 22px;
}

.words-cat-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.words-cat-btn {
  background: var(--cream);
  border: none;
  border-radius: var(--radius-md);
  padding: 24px 16px;
  font-size: 1.25rem;
  font-family: inherit;
  font-weight: 600;
  color: var(--text);
  cursor: pointer;
  box-shadow: var(--shadow-sm);
  transition: transform 0.18s cubic-bezier(.34,1.56,.64,1), background 0.15s;
}
.words-cat-btn:active { transform: scale(0.94); }
.words-cat-btn:hover  { background: #ECFDF5; }

/* ─── Greeting Card ──────────────────────────────────────── */
.greeting-card {
  background: linear-gradient(135deg, #ECFDF5, #D1FAE5);
  border-radius: var(--radius-lg);
  padding: 36px 24px 28px;
  text-align: center;
  box-shadow: var(--shadow-md);
  cursor: pointer;
  transition: transform 0.15s;
  margin-bottom: 16px;
}
.greeting-card:active { transform: scale(0.98); }

.greeting-emoji { font-size: 4rem; margin-bottom: 14px; }
.greeting-en    { font-size: 2rem; font-weight: 700; color: #059669; margin-bottom: 10px; letter-spacing: 0.02em; }
.greeting-cn    { font-size: 1.3rem; color: var(--text-soft); margin-bottom: 14px; }
.greeting-tap   { font-size: 0.88rem; color: #6EE7B7; }

.greeting-progress {
  text-align: center;
  color: var(--text-soft);
  font-size: 0.9rem;
  margin-bottom: 18px;
}

/* ─── Responsive ─────────────────────────────────────────── */
.menu-featured {
  margin-bottom: 16px;
}

.menu-featured .menu-btn {
  width: 100%;
  flex-direction: row;
  justify-content: space-between;
  align-items: center;
  padding: 26px 28px;
  border-radius: var(--radius-lg);
  position: relative;
}

.menu-btn-inner {
  display: flex;
  align-items: center;
  gap: 18px;
}

.menu-featured .menu-btn .icon {
  font-size: 3rem;
  margin-bottom: 0;
}

.menu-featured .menu-btn .label {
  font-size: 1.45rem;
  display: block;
}

.menu-featured .menu-btn .desc {
  font-size: 0.9rem;
  margin-top: 4px;
  display: block;
}

.new-badge {
  background: rgba(255,255,255,0.28);
  border: 2px solid rgba(255,255,255,0.55);
  color: white;
  font-size: 0.85rem;
  font-weight: 700;
  border-radius: 50px;
  padding: 4px 12px;
  letter-spacing: 0.05em;
  flex-shrink: 0;
}

.menu-btn.math {
  background: linear-gradient(145deg, #F97316, #EA580C);
  box-shadow: 0 10px 30px rgba(249,115,22,0.42);
}

/* ─── Math Content Displays ──────────────────────────────── */
.math-number-display {
  font-size: 5rem;
  font-weight: 700;
  text-align: center;
  color: var(--coral);
  letter-spacing: 4px;
  margin-bottom: 8px;
  line-height: 1.1;
}

.math-calc-display {
  font-size: 2.6rem;
  font-weight: 700;
  text-align: center;
  color: var(--text);
  margin-bottom: 10px;
  letter-spacing: 2px;
}

.math-shape-display {
  font-size: 7rem;
  text-align: center;
  margin-bottom: 10px;
  line-height: 1.1;
  color: var(--teal-dk);
}

.math-pattern-seq {
  display: flex;
  justify-content: center;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 12px;
  padding: 16px 0;
}

.pattern-item {
  font-size: 2rem;
  min-width: 44px;
  text-align: center;
  background: var(--cream);
  border-radius: 12px;
  padding: 8px;
}

.pattern-blank {
  background: #E8E0FF;
  color: var(--violet-dk);
  font-weight: 700;
  font-size: 2rem;
  animation: pulse 1.2s infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50%       { opacity: 0.5; }
}

/* ─── Math tab active color override ────────────────────── */
#math-screen .tab-btn.active {
  background: linear-gradient(135deg, #F97316, #EA580C);
  box-shadow: 0 4px 12px rgba(234,88,12,0.35);
}

/* ─── Responsive ─────────────────────────────────────────── */
@media (max-width: 600px) {
  .cards-grid     { grid-template-columns: repeat(3, 1fr); }
  .menu-grid      { gap: 14px; }
  .menu-btn       { padding: 28px 14px 24px; border-radius: var(--radius-md); }
  .menu-btn .icon { font-size: 2.9rem; }
  .quiz-question  { font-size: 2.4rem; }
  .container      { padding: 20px 16px 36px; }
}

@media (max-width: 400px) {
  .option-btn { font-size: 1.3rem; padding: 16px; }
  .cards-grid { grid-template-columns: repeat(3, 1fr); gap: 9px; }
}

/* ══ POWER UP 2 ════════════════════════════════════════ */
:root {
  --pu2-accent:        #EC4899;
  --pu2-accent-dk:     #BE185D;
  --pu2-accent-soft:   #FCE7F3;
  --pu2-card-front:    linear-gradient(145deg, #60A5FA, #3B82F6);
  --pu2-card-back:     linear-gradient(145deg, #FBBF24, #F59E0B);
  --pu2-mode-browse:   linear-gradient(145deg, #60A5FA, #3B82F6);
  --pu2-mode-flash:    linear-gradient(145deg, #FB923C, #EA580C);
  --pu2-mode-quiz:     linear-gradient(145deg, #34D399, #059669);
  --pu2-mode-spell:    linear-gradient(145deg, #A78BFA, #7C3AED);
}

/* ─── Unit Grid ──────────────────────────────────────── */
.pu2-unit-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: 14px;
  margin-top: 8px;
}

.pu2-unit-card {
  background: var(--white);
  border: none;
  border-radius: var(--radius-md);
  padding: 20px 14px 16px;
  cursor: pointer;
  text-align: center;
  font-family: inherit;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  box-shadow: var(--shadow-sm);
  border-bottom: 4px solid var(--pu2-accent-soft);
  transition: transform 0.18s cubic-bezier(.34,1.56,.64,1), box-shadow 0.18s;
}

.pu2-unit-card:hover  { transform: translateY(-3px) scale(1.02); box-shadow: var(--shadow-md); }
.pu2-unit-card:active { transform: scale(0.95); }

.pu2-unit-emoji {
  font-size: 2.5rem;
  line-height: 1;
  margin-bottom: 4px;
}

.pu2-unit-num {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--pu2-accent-dk);
  letter-spacing: 0.02em;
}

.pu2-unit-topic {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text);
}

.pu2-unit-topic-cn {
  font-size: 0.82rem;
  color: var(--text-soft);
}

.pu2-unit-count {
  display: inline-block;
  margin-top: 6px;
  background: var(--pu2-accent-soft);
  color: var(--pu2-accent-dk);
  font-size: 0.75rem;
  font-weight: 600;
  border-radius: 50px;
  padding: 3px 10px;
}

/* ─── Unit Header ────────────────────────────────────── */
.pu2-unit-header {
  display: flex;
  align-items: center;
  gap: 14px;
  background: var(--white);
  border-radius: var(--radius-md);
  padding: 16px 20px;
  margin-bottom: 18px;
  box-shadow: var(--shadow-sm);
}

.pu2-unit-header .pu2-unit-emoji { font-size: 2.4rem; margin: 0; }
.pu2-unit-header .pu2-unit-title {
  flex: 1;
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text);
  line-height: 1.3;
}
.pu2-unit-header .pu2-unit-title small {
  display: block;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-soft);
  margin-top: 2px;
}
.pu2-unit-header .pu2-unit-count { margin: 0; }

/* ─── Back Button (in-tab) ───────────────────────────── */
.pu2-back-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--white);
  border: 2px solid #E5E5E5;
  color: var(--text);
  border-radius: var(--radius-sm);
  padding: 10px 16px;
  min-height: 44px;
  font-size: 0.9rem;
  font-family: inherit;
  font-weight: 500;
  cursor: pointer;
  margin-bottom: 14px;
  box-shadow: var(--shadow-sm);
  transition: background 0.15s, transform 0.15s;
}
.pu2-back-btn:hover  { background: var(--cream); }
.pu2-back-btn:active { transform: scale(0.96); }

/* ─── Modes Grid ─────────────────────────────────────── */
.pu2-modes-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
  margin-top: 6px;
}

.pu2-mode-btn {
  border: none;
  border-radius: var(--radius-lg);
  padding: 22px 14px 18px;
  cursor: pointer;
  font-family: inherit;
  color: var(--white);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 130px;
  text-align: center;
  transition: transform 0.18s cubic-bezier(.34,1.56,.64,1), box-shadow 0.18s;
}

.pu2-mode-btn:hover  { transform: translateY(-3px); }
.pu2-mode-btn:active { transform: scale(0.95); }

.pu2-mode-btn.browse   { background: var(--pu2-mode-browse);  box-shadow: 0 8px 22px rgba(59,130,246,0.40); }
.pu2-mode-btn.flash    { background: var(--pu2-mode-flash);   box-shadow: 0 8px 22px rgba(234,88,12,0.38); }
.pu2-mode-btn.quiz     { background: var(--pu2-mode-quiz);    box-shadow: 0 8px 22px rgba(5,150,105,0.38); }
.pu2-mode-btn.spell    { background: var(--pu2-mode-spell);   box-shadow: 0 8px 22px rgba(124,58,237,0.40); }

.pu2-mode-icon {
  font-size: 2.5rem;
  line-height: 1;
  filter: drop-shadow(0 3px 6px rgba(0,0,0,0.18));
}

.pu2-mode-label {
  font-size: 1.1rem;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.pu2-mode-label small {
  display: block;
  font-size: 0.78rem;
  font-weight: 500;
  opacity: 0.88;
  margin-top: 3px;
}

/* ─── Word List (Browse) ─────────────────────────────── */
.pu2-word-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.pu2-word-row {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 14px;
  background: var(--white);
  border-radius: var(--radius-md);
  padding: 14px 16px;
  box-shadow: var(--shadow-sm);
  border-left: 4px solid var(--pu2-accent-soft);
  cursor: pointer;
  transition: background 0.15s, transform 0.15s;
}
.pu2-word-row:hover  { background: var(--cream); }
.pu2-word-row:active { transform: scale(0.98); }

.pu2-word-emoji {
  font-size: 2rem;
  line-height: 1;
}

.pu2-word-main {
  display: flex;
  flex-direction: column;
  gap: 3px;
  min-width: 0;
}

.pu2-word-en {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text);
  display: inline-flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.pu2-word-pos {
  display: inline-block;
  background: #E8E0FF;
  color: var(--violet-dk);
  font-size: 0.7rem;
  font-weight: 600;
  border-radius: 50px;
  padding: 2px 8px;
  letter-spacing: 0.03em;
}

.pu2-word-cn {
  font-size: 0.95rem;
  color: var(--text-soft);
}

.pu2-word-example {
  font-size: 0.85rem;
  font-style: italic;
  color: #6B7280;
  margin-top: 2px;
}

.pu2-word-example-cn {
  font-size: 0.78rem;
  color: #9CA3AF;
}

.pu2-word-speak {
  background: var(--pu2-accent-soft);
  border: none;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  font-size: 1.1rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform 0.15s, background 0.15s;
}
.pu2-word-speak:hover  { background: var(--pu2-accent); color: var(--white); transform: scale(1.1); }
.pu2-word-speak:active { transform: scale(0.92); }

/* ─── Flashcard ──────────────────────────────────────── */
.pu2-flashcard {
  width: 280px;
  height: 360px;
  max-width: 100%;
  margin: 10px auto 18px;
  perspective: 1000px;
}

.pu2-card-inner {
  position: relative;
  width: 100%;
  height: 100%;
  transition: transform 0.6s cubic-bezier(.34,1.56,.64,1);
  transform-style: preserve-3d;
  transform: rotateY(0deg);
}

.pu2-flashcard.flipped .pu2-card-inner {
  transform: rotateY(180deg);
}

.pu2-card-face {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  -webkit-backface-visibility: hidden;
          backface-visibility: hidden;
  border-radius: var(--radius-lg);
  padding: 26px 22px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  gap: 12px;
  box-shadow: var(--shadow-md);
  cursor: pointer;
  color: var(--white);
}

.pu2-card-face.front {
  background: var(--pu2-card-front);
}

.pu2-card-face.back {
  background: var(--pu2-card-back);
  transform: rotateY(180deg);
}

.pu2-card-emoji {
  font-size: 3.5rem;
  line-height: 1;
  filter: drop-shadow(0 3px 8px rgba(0,0,0,0.18));
}

.pu2-card-word {
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  word-break: break-word;
}

.pu2-card-cn {
  font-size: 1.5rem;
  font-weight: 600;
}

.pu2-card-example {
  font-size: 1rem;
  font-style: italic;
  padding: 0 6px;
  opacity: 0.95;
}

.pu2-card-example-cn {
  font-size: 0.9rem;
  opacity: 0.85;
}

.pu2-card-speak {
  position: absolute;
  top: 12px;
  right: 12px;
  background: rgba(255,255,255,0.25);
  border: none;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  font-size: 1rem;
  color: var(--white);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform 0.15s, background 0.15s;
}
.pu2-card-speak:hover  { background: rgba(255,255,255,0.4); transform: scale(1.12); }
.pu2-card-speak:active { transform: scale(0.92); }

.pu2-flash-nav {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 18px;
  margin-top: 10px;
}

.pu2-flash-progress {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-soft);
  min-width: 70px;
  text-align: center;
}

/* ─── Quiz ───────────────────────────────────────────── */
.pu2-quiz-box {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 30px 26px;
  box-shadow: var(--shadow-md);
  margin-top: 8px;
}

.pu2-quiz-display {
  text-align: center;
  margin-bottom: 22px;
}

.pu2-quiz-emoji {
  font-size: 4rem;
  line-height: 1;
  margin-bottom: 8px;
}

.pu2-quiz-cn {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text);
}

.pu2-quiz-hint {
  font-size: 0.92rem;
  color: var(--text-soft);
  margin-top: 6px;
}

.pu2-options-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.pu2-opt-btn {
  background: var(--cream);
  border: 3px solid var(--pu2-accent-soft);
  border-radius: var(--radius-md);
  padding: 24px 18px;
  font-size: 1.3rem;
  font-family: inherit;
  font-weight: 600;
  color: var(--text);
  cursor: pointer;
  transition: all 0.18s cubic-bezier(.34,1.56,.64,1);
}

.pu2-opt-btn:hover  { background: var(--pu2-accent-soft); }
.pu2-opt-btn:active { transform: scale(0.95); }

.pu2-opt-btn.correct {
  background: #DCFCE7;
  border-color: #22C55E;
  color: #15803D;
  animation: pu2-pop 0.4s cubic-bezier(.34,1.56,.64,1);
}

.pu2-opt-btn.wrong {
  background: #FEE2E2;
  border-color: #EF4444;
  color: #B91C1C;
  animation: pu2-shake 0.3s ease-out;
}

/* ─── Spelling ───────────────────────────────────────── */
.pu2-spell-box {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 32px 26px;
  box-shadow: var(--shadow-md);
  margin-top: 8px;
  text-align: center;
}

.pu2-spell-prompt {
  margin-bottom: 22px;
}

.pu2-spell-emoji {
  font-size: 3rem;
  line-height: 1;
  margin-bottom: 8px;
}

.pu2-spell-cn {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--text);
}

.pu2-spell-hint {
  font-size: 0.88rem;
  color: var(--text-soft);
  margin-top: 6px;
}

.pu2-spell-input {
  width: 100%;
  max-width: 360px;
  font-family: inherit;
  font-size: 1.5rem;
  font-weight: 600;
  text-align: center;
  letter-spacing: 0.05em;
  padding: 14px 18px;
  border: 3px solid #E5E5E5;
  border-radius: var(--radius-md);
  background: var(--cream);
  color: var(--text);
  outline: none;
  transition: border-color 0.18s, background 0.18s, color 0.18s;
}

.pu2-spell-input:focus {
  border-color: var(--pu2-accent);
  background: var(--white);
}

.pu2-spell-input.correct {
  border-color: #22C55E;
  background: #DCFCE7;
  color: #15803D;
  animation: pu2-pop 0.4s cubic-bezier(.34,1.56,.64,1);
}

.pu2-spell-input.wrong {
  border-color: #EF4444;
  background: #FEE2E2;
  color: #B91C1C;
  animation: pu2-shake 0.3s ease-out;
}

.pu2-spell-feedback {
  margin-top: 14px;
  min-height: 1.4em;
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-soft);
}

.pu2-spell-feedback.correct { color: #15803D; }
.pu2-spell-feedback.wrong   { color: #B91C1C; }

.pu2-spell-actions {
  display: flex;
  justify-content: center;
  gap: 10px;
  margin-top: 18px;
  flex-wrap: wrap;
}

/* ─── Completion ─────────────────────────────────────── */
.pu2-complete {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 44px 30px;
  text-align: center;
  box-shadow: var(--shadow-lg);
}

.pu2-complete .big-emoji {
  font-size: 5rem;
  display: block;
  margin-bottom: 16px;
  animation: bounceIn 0.5s cubic-bezier(.34,1.56,.64,1);
}

.pu2-complete h2 {
  font-size: 2rem;
  font-weight: 700;
  color: var(--pu2-accent-dk);
  margin-bottom: 10px;
}

.pu2-complete .pu2-score {
  color: var(--text-soft);
  font-size: 1.15rem;
  margin-bottom: 24px;
}

.pu2-complete .pu2-score strong {
  color: var(--pu2-accent-dk);
  font-size: 1.3rem;
}

/* ─── Animations ─────────────────────────────────────── */
@keyframes pu2-shake {
  0%   { transform: translateX(0); }
  25%  { transform: translateX(-6px); }
  50%  { transform: translateX(6px); }
  75%  { transform: translateX(-4px); }
  100% { transform: translateX(0); }
}

@keyframes pu2-pop {
  0%   { transform: scale(1); }
  50%  { transform: scale(1.08); }
  100% { transform: scale(1); }
}

/* ─── PU2 Responsive ─────────────────────────────────── */
@media (max-width: 600px) {
  .pu2-unit-grid     { grid-template-columns: repeat(2, 1fr); gap: 12px; }
  .pu2-unit-card     { padding: 16px 10px 12px; }
  .pu2-unit-emoji    { font-size: 2.1rem; }
  .pu2-mode-btn      { min-height: 110px; padding: 18px 10px 14px; }
  .pu2-mode-icon     { font-size: 2.1rem; }
  .pu2-mode-label    { font-size: 1rem; }
  .pu2-flashcard     { width: 100%; height: 340px; }
  .pu2-card-word     { font-size: 1.7rem; }
  .pu2-card-cn       { font-size: 1.3rem; }
  .pu2-card-emoji    { font-size: 3rem; }
  .pu2-quiz-emoji    { font-size: 3.4rem; }
  .pu2-quiz-cn       { font-size: 1.3rem; }
  .pu2-opt-btn       { font-size: 1.1rem; padding: 18px 12px; }
  .pu2-quiz-box,
  .pu2-spell-box     { padding: 24px 18px; }
  .pu2-spell-input   { font-size: 1.3rem; }
  .pu2-word-row      { padding: 12px 14px; gap: 10px; }
  .pu2-word-en       { font-size: 1.1rem; }
}

@media (max-width: 400px) {
  .pu2-unit-grid     { grid-template-columns: repeat(2, 1fr); gap: 10px; }
  .pu2-mode-btn      { min-height: 100px; }
}

/* ── PU2 v2 layout ────────── */

/* Section type accent palette (kid-friendly pastels) */
:root {
  --pu2-vocab-bg:    linear-gradient(145deg, #DBEAFE, #BFDBFE);
  --pu2-vocab-ink:   #1D4ED8;
  --pu2-vocab-ring:  #60A5FA;

  --pu2-grammar-bg:  linear-gradient(145deg, #EDE9FE, #DDD6FE);
  --pu2-grammar-ink: #6D28D9;
  --pu2-grammar-ring:#A78BFA;

  --pu2-farm-bg:     linear-gradient(145deg, #DCFCE7, #BBF7D0);
  --pu2-farm-ink:    #047857;
  --pu2-farm-ring:   #34D399;

  --pu2-cross-bg:    linear-gradient(145deg, #FFEDD5, #FED7AA);
  --pu2-cross-ink:   #C2410C;
  --pu2-cross-ring:  #FB923C;

  --pu2-lit-bg:      linear-gradient(145deg, #FCE7F3, #FBCFE8);
  --pu2-lit-ink:     #BE185D;
  --pu2-lit-ring:    #F472B6;
}

/* ─── Section Tabs (entry cards inside a unit) ───────── */
.pu2-section-tabs {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
  margin-top: 10px;
}

.pu2-section-card {
  position: relative;
  border: none;
  border-radius: var(--radius-md);
  padding: 22px 14px 18px;
  cursor: pointer;
  font-family: inherit;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  min-height: 140px;
  text-align: center;
  background: var(--white);
  box-shadow: var(--shadow-sm);
  border-bottom: 4px solid rgba(0,0,0,0.06);
  transition: transform 0.18s cubic-bezier(.34,1.56,.64,1), box-shadow 0.18s;
}

.pu2-section-card:hover  { transform: translateY(-3px) scale(1.02); box-shadow: var(--shadow-md); }
.pu2-section-card:active { transform: scale(0.96); }

.pu2-section-card.is-vocab   { background: var(--pu2-vocab-bg);   border-bottom-color: var(--pu2-vocab-ring); }
.pu2-section-card.is-grammar { background: var(--pu2-grammar-bg); border-bottom-color: var(--pu2-grammar-ring); }
.pu2-section-card.is-farm    { background: var(--pu2-farm-bg);    border-bottom-color: var(--pu2-farm-ring); }
.pu2-section-card.is-cross   { background: var(--pu2-cross-bg);   border-bottom-color: var(--pu2-cross-ring); }
.pu2-section-card.is-lit     { background: var(--pu2-lit-bg);     border-bottom-color: var(--pu2-lit-ring); }

.pu2-section-icon {
  font-size: 2.8rem;
  line-height: 1;
  filter: drop-shadow(0 3px 6px rgba(0,0,0,0.12));
  margin-bottom: 2px;
}

.pu2-section-label {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text);
  letter-spacing: 0.02em;
}

.pu2-section-card.is-vocab   .pu2-section-label { color: var(--pu2-vocab-ink); }
.pu2-section-card.is-grammar .pu2-section-label { color: var(--pu2-grammar-ink); }
.pu2-section-card.is-farm    .pu2-section-label { color: var(--pu2-farm-ink); }
.pu2-section-card.is-cross   .pu2-section-label { color: var(--pu2-cross-ink); }
.pu2-section-card.is-lit     .pu2-section-label { color: var(--pu2-lit-ink); }

.pu2-section-sub {
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--text-soft);
  margin-top: -2px;
}

.pu2-section-count {
  display: inline-block;
  margin-top: 6px;
  background: rgba(255,255,255,0.78);
  color: var(--text);
  font-size: 0.75rem;
  font-weight: 700;
  border-radius: 50px;
  padding: 3px 10px;
  box-shadow: 0 2px 6px rgba(0,0,0,0.06);
}

.pu2-section-card.is-vocab   .pu2-section-count { color: var(--pu2-vocab-ink); }
.pu2-section-card.is-grammar .pu2-section-count { color: var(--pu2-grammar-ink); }
.pu2-section-card.is-farm    .pu2-section-count { color: var(--pu2-farm-ink); }
.pu2-section-card.is-cross   .pu2-section-count { color: var(--pu2-cross-ink); }
.pu2-section-card.is-lit     .pu2-section-count { color: var(--pu2-lit-ink); }

/* ─── Section Header (cross / lit grouped lists) ─────── */
.pu2-section-header {
  background: var(--white);
  border-radius: var(--radius-md);
  padding: 14px 18px;
  margin: 18px 0 10px;
  box-shadow: var(--shadow-sm);
  border-left: 5px solid var(--pu2-accent);
}

.pu2-section-header .title {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text);
  display: block;
}

.pu2-section-header .titleCn {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-soft);
  display: block;
  margin-top: 2px;
}

/* ─── Vocab Read-Along Card ──────────────────────────── */
.pu2-vocab-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 28px 22px 24px;
  box-shadow: var(--shadow-md);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
  margin: 10px 0 18px;
  border-top: 6px solid var(--pu2-vocab-ring);
  text-align: center;
}

.pu2-vocab-cat {
  display: inline-block;
  background: var(--pu2-vocab-bg);
  color: var(--pu2-vocab-ink);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  padding: 4px 12px;
  border-radius: 50px;
  box-shadow: 0 2px 6px rgba(0,0,0,0.06);
}

.pu2-vocab-emoji {
  font-size: 4.2rem;
  line-height: 1;
  filter: drop-shadow(0 4px 10px rgba(0,0,0,0.14));
  margin: 4px 0 0;
}

.pu2-vocab-word {
  font-size: 3rem;
  font-weight: 800;
  color: var(--text);
  line-height: 1.1;
  letter-spacing: 0.01em;
  word-break: break-word;
}

.pu2-vocab-cn {
  font-size: 1.4rem;
  font-weight: 500;
  color: var(--text-soft);
  margin-top: -2px;
}

/* Read-along progress meter */
.pu2-readalong-meter {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  margin: 8px 0 2px;
  min-height: 22px;
}

.pu2-readalong-dot {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: #E5E7EB;
  box-shadow: inset 0 1px 2px rgba(0,0,0,0.08);
  transition: background 0.25s, transform 0.25s, box-shadow 0.25s;
}

.pu2-readalong-dot.active {
  background: var(--pu2-vocab-ring);
  transform: scale(1.35);
  box-shadow: 0 0 0 6px rgba(96,165,250,0.25);
  animation: pu2-dot-pulse 1.1s ease-in-out infinite;
}

.pu2-readalong-dot.done {
  background: #34D399;
  box-shadow: 0 0 12px rgba(52,211,153,0.65);
  animation: pu2-dot-glow 0.7s ease-out 1;
}

@keyframes pu2-dot-pulse {
  0%, 100% { transform: scale(1.25); box-shadow: 0 0 0 4px  rgba(96,165,250,0.30); }
  50%      { transform: scale(1.50); box-shadow: 0 0 0 10px rgba(96,165,250,0.10); }
}

@keyframes pu2-dot-glow {
  0%   { box-shadow: 0 0 0 0   rgba(52,211,153,0.85); transform: scale(1.5); }
  60%  { box-shadow: 0 0 0 14px rgba(52,211,153,0.00); transform: scale(1.15); }
  100% { box-shadow: 0 0 12px rgba(52,211,153,0.65);  transform: scale(1); }
}

.pu2-readalong-status {
  font-size: 1rem;
  font-weight: 600;
  color: var(--pu2-vocab-ink);
  letter-spacing: 0.02em;
  min-height: 1.4em;
}

.pu2-vocab-replay {
  border: none;
  background: var(--pu2-vocab-bg);
  color: var(--pu2-vocab-ink);
  border-radius: 50px;
  padding: 10px 22px;
  font-family: inherit;
  font-size: 0.95rem;
  font-weight: 700;
  cursor: pointer;
  box-shadow: 0 4px 12px rgba(59,130,246,0.18);
  transition: transform 0.15s, box-shadow 0.15s;
}

.pu2-vocab-replay:hover  { transform: translateY(-2px); box-shadow: 0 6px 16px rgba(59,130,246,0.28); }
.pu2-vocab-replay:active { transform: scale(0.95); }

.pu2-vocab-nav {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  width: 100%;
  margin-top: 6px;
}

.pu2-vocab-nav button {
  flex: 1;
  border: none;
  border-radius: var(--radius-sm);
  padding: 14px 10px;
  font-family: inherit;
  font-size: 1rem;
  font-weight: 700;
  color: var(--white);
  background: linear-gradient(145deg, #60A5FA, #3B82F6);
  cursor: pointer;
  box-shadow: 0 6px 16px rgba(59,130,246,0.30);
  transition: transform 0.15s, box-shadow 0.15s, opacity 0.15s;
}

.pu2-vocab-nav button:hover  { transform: translateY(-2px); box-shadow: 0 8px 20px rgba(59,130,246,0.38); }
.pu2-vocab-nav button:active { transform: scale(0.95); }

.pu2-vocab-card.locked .pu2-vocab-nav button.next,
.pu2-vocab-nav button:disabled {
  background: #E5E7EB;
  color: #9CA3AF;
  cursor: not-allowed;
  box-shadow: none;
  transform: none;
  opacity: 0.85;
}

/* ─── Grammar List ───────────────────────────────────── */
.pu2-grammar-card {
  background: var(--white);
  border-radius: var(--radius-md);
  padding: 18px 18px 14px;
  margin: 12px 0;
  box-shadow: var(--shadow-sm);
  border-left: 5px solid var(--pu2-grammar-ring);
}

.pu2-grammar-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--pu2-grammar-ink);
  line-height: 1.3;
}

.pu2-grammar-title-cn {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-soft);
  margin-top: 2px;
  margin-bottom: 12px;
  display: block;
}

.pu2-grammar-examples {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.pu2-grammar-example {
  background: var(--pu2-grammar-bg);
  border-radius: var(--radius-sm);
  padding: 12px 14px;
  cursor: pointer;
  transition: transform 0.15s, box-shadow 0.15s, background 0.15s;
  display: flex;
  flex-direction: column;
  gap: 3px;
}

.pu2-grammar-example:hover  {
  transform: translateX(3px);
  box-shadow: 0 4px 12px rgba(124,58,237,0.18);
}
.pu2-grammar-example:active { transform: scale(0.98); }

.pu2-grammar-example .en {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text);
  line-height: 1.35;
}

.pu2-grammar-example .cn {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-soft);
}

/* ─── Generic List (Farm / Cross / Lit) ──────────────── */
.pu2-list {
  list-style: none;
  padding: 0;
  margin: 8px 0 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.pu2-list-item {
  background: var(--white);
  border-radius: var(--radius-sm);
  padding: 14px 16px;
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: 10px;
  box-shadow: var(--shadow-sm);
  cursor: pointer;
  transition: transform 0.15s, box-shadow 0.15s;
  border-left: 4px solid transparent;
}

.pu2-list-item:hover  { transform: translateX(3px); box-shadow: var(--shadow-md); }
.pu2-list-item:active { transform: scale(0.98); }

/* Per-section accent edges (parent .pu2-list may carry these) */
.pu2-list.is-farm  .pu2-list-item { border-left-color: var(--pu2-farm-ring); }
.pu2-list.is-cross .pu2-list-item { border-left-color: var(--pu2-cross-ring); }
.pu2-list.is-lit   .pu2-list-item { border-left-color: var(--pu2-lit-ring); }

.pu2-list-en {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text);
  line-height: 1.3;
  display: block;
}

.pu2-list-cn {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-soft);
  margin-top: 2px;
  display: block;
}

.pu2-list-speaker {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--pu2-accent-soft);
  color: var(--pu2-accent-dk);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  flex-shrink: 0;
  box-shadow: 0 2px 6px rgba(0,0,0,0.08);
  transition: transform 0.15s, background 0.15s;
}

.pu2-list-item:hover .pu2-list-speaker {
  transform: scale(1.1);
  background: var(--pu2-accent);
  color: var(--white);
}

/* ─── Tablet / iPad ──────────────────────────────────── */
@media (min-width: 700px) {
  .pu2-section-tabs    { grid-template-columns: repeat(3, 1fr); gap: 18px; }
  .pu2-vocab-word      { font-size: 3.6rem; }
  .pu2-vocab-cn        { font-size: 1.6rem; }
  .pu2-vocab-emoji     { font-size: 5rem; }
  .pu2-grammar-title   { font-size: 1.4rem; }
  .pu2-grammar-example .en { font-size: 1.15rem; }
  .pu2-list-en         { font-size: 1.2rem; }
}

/* ─── Small phones ───────────────────────────────────── */
@media (max-width: 400px) {
  .pu2-section-tabs    { gap: 10px; }
  .pu2-section-card    { min-height: 120px; padding: 18px 10px 14px; }
  .pu2-section-icon    { font-size: 2.3rem; }
  .pu2-section-label   { font-size: 1rem; }
  .pu2-vocab-card      { padding: 22px 16px 20px; }
  .pu2-vocab-word      { font-size: 2.4rem; }
  .pu2-vocab-cn        { font-size: 1.2rem; }
  .pu2-vocab-emoji     { font-size: 3.4rem; }
  .pu2-readalong-meter { gap: 10px; }
  .pu2-heart           { font-size: 1.6rem; }
  .pu2-vocab-nav button{ font-size: 0.95rem; padding: 12px 8px; }
}

/* ─── PU2 v3: Bubblegum Storybook polish ───────────────────────── */

/* Card – overlay a soft confetti-dot pattern + pastel sky→mint gradient */
.pu2-vocab-card {
  position: relative;
  background:
    radial-gradient(circle at 18% 22%, rgba(255,255,255,0.9) 0 1px, transparent 1.5px) 0 0/22px 22px,
    radial-gradient(circle at 78% 68%, rgba(255,255,255,0.7) 0 1px, transparent 1.5px) 11px 11px/22px 22px,
    linear-gradient(160deg, #E0F2FE 0%, #DBEAFE 45%, #DCFCE7 100%);
  border-top: 0;
  border: 3px solid #fff;
  box-shadow:
    0 18px 40px -12px rgba(59,130,246,0.22),
    0 4px 0 rgba(255,255,255,0.6) inset;
  overflow: hidden;
  padding: 26px 22px 22px;
}

.pu2-vocab-card::before {
  /* sticker shine */
  content: '';
  position: absolute;
  top: -40px; left: -40px;
  width: 140px; height: 140px;
  background: radial-gradient(circle, rgba(255,255,255,0.55), transparent 70%);
  pointer-events: none;
}

/* Category sticker – tilted */
.pu2-vocab-cat {
  position: absolute;
  top: 14px;
  right: 14px;
  transform: rotate(6deg);
  background: linear-gradient(140deg, #FEF3C7, #FDE68A);
  color: #92400E;
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 5px 12px;
  border-radius: 50px;
  box-shadow: 0 3px 10px rgba(0,0,0,0.10), 0 1px 0 rgba(255,255,255,0.7) inset;
  border: 2px solid #fff;
  z-index: 2;
}

/* Emoji bobs gently */
.pu2-vocab-emoji {
  font-size: 4.6rem;
  margin-top: 6px;
  animation: pu2-bob 3.4s ease-in-out infinite;
  filter: drop-shadow(0 6px 14px rgba(0,0,0,0.16));
}
@keyframes pu2-bob {
  0%, 100% { transform: translateY(0) rotate(-2deg); }
  50%      { transform: translateY(-6px) rotate(2deg); }
}

.pu2-vocab-word {
  cursor: pointer;
  user-select: none;
  text-shadow: 0 2px 0 rgba(255,255,255,0.7);
  transition: transform 0.18s;
}
.pu2-vocab-word:active { transform: scale(0.97); }

@keyframes pu2-word-pop {
  0%   { transform: scale(1);    }
  35%  { transform: scale(1.08); }
  100% { transform: scale(1);    }
}
.pu2-vocab-word.pop {
  animation: pu2-word-pop 0.42s cubic-bezier(.34,1.56,.64,1);
}

/* IPA hint (subtle, monospace-like). Empty placeholder reserves the space. */
.pu2-vocab-ipa {
  font-family: ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  font-size: 0.95rem;
  font-weight: 500;
  color: rgba(29,78,216,0.55);
  letter-spacing: 0.04em;
  margin-top: -6px;
  min-height: 1.1em;
}
.pu2-vocab-ipa-empty { visibility: hidden; }

/* Progress chip above the card */
.pu2-vocab-progress {
  text-align: center;
  margin: 8px auto 10px;
  font-size: 0.95rem;
  color: var(--text-soft);
  font-weight: 600;
}
.pu2-vocab-progress-num {
  display: inline-block;
  margin-left: 6px;
  background: #fff;
  color: #1D4ED8;
  padding: 2px 10px;
  border-radius: 50px;
  box-shadow: 0 2px 8px rgba(59,130,246,0.18);
  font-weight: 800;
}
.pu2-vocab-progress-sep { color: #9CA3AF; margin: 0 2px; font-weight: 600; }

/* ── Heart-based read-along meter ── */
.pu2-readalong-meter {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 14px;
  margin: 6px 0 2px;
  min-height: 36px;
}

.pu2-heart {
  display: inline-block;
  font-size: 1.9rem;
  line-height: 1;
  /* Outline heart by default: paint with stroke via text-shadow trick */
  color: transparent;
  -webkit-text-stroke: 2px #94A3B8;
  text-shadow: none;
  transition: color 0.25s, -webkit-text-stroke-color 0.25s, transform 0.25s, filter 0.25s;
}

.pu2-heart.active {
  -webkit-text-stroke-color: #F472B6;
  color: rgba(244,114,182,0.18);
  animation: pu2-heart-pulse 1.05s ease-in-out infinite;
}

@keyframes pu2-heart-pulse {
  0%, 100% { transform: scale(1.05); filter: drop-shadow(0 0 0 rgba(244,114,182,0)); }
  50%      { transform: scale(1.25); filter: drop-shadow(0 0 8px rgba(244,114,182,0.55)); }
}

.pu2-heart.done {
  color: #F472B6;
  -webkit-text-stroke-color: #DB2777;
  animation: pu2-heart-stamp 0.5s cubic-bezier(.34,1.56,.64,1) 1;
  filter: drop-shadow(0 4px 8px rgba(244,114,182,0.45));
}

@keyframes pu2-heart-stamp {
  0%   { transform: scale(0.4) rotate(-18deg); }
  60%  { transform: scale(1.35) rotate(6deg);  }
  100% { transform: scale(1)    rotate(0deg);  }
}

.pu2-heart.error {
  color: #FCA5A5;
  -webkit-text-stroke-color: #DC2626;
  animation: pu2-heart-shake 0.45s ease-in-out 1;
  filter: drop-shadow(0 0 6px rgba(220,38,38,0.45));
}

@keyframes pu2-heart-shake {
  0%, 100% { transform: translateX(0); }
  20%      { transform: translateX(-4px) rotate(-6deg); }
  40%      { transform: translateX(4px)  rotate(6deg); }
  60%      { transform: translateX(-3px) rotate(-3deg); }
  80%      { transform: translateX(3px)  rotate(3deg); }
}

/* Status line – rounded pill */
.pu2-readalong-status {
  display: inline-block;
  background: rgba(255,255,255,0.85);
  padding: 6px 14px;
  border-radius: 50px;
  font-size: 0.95rem;
  font-weight: 700;
  color: #1D4ED8;
  box-shadow: 0 2px 8px rgba(0,0,0,0.06);
  min-height: 1.4em;
}

/* Replay button – sweet rubber-band press */
.pu2-vocab-replay {
  border: 3px solid #fff;
  background: linear-gradient(140deg, #FBCFE8, #F9A8D4);
  color: #9D174D;
  border-radius: 50px;
  padding: 10px 22px;
  font-family: inherit;
  font-size: 1rem;
  font-weight: 800;
  letter-spacing: 0.02em;
  cursor: pointer;
  box-shadow: 0 6px 16px rgba(244,114,182,0.32), 0 1px 0 rgba(255,255,255,0.9) inset;
  transition: transform 0.18s cubic-bezier(.34,1.56,.64,1), box-shadow 0.18s;
}
.pu2-vocab-replay:hover  { transform: translateY(-2px) scale(1.03); }
.pu2-vocab-replay:active { transform: scale(0.92); }

/* Nav buttons (outside the card now) */
.pu2-vocab-nav {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  width: 100%;
  margin-top: 14px;
}

.pu2-vocab-nav-prev,
.pu2-vocab-nav-next {
  flex: 1;
  border: none;
  border-radius: 18px;
  padding: 14px 10px;
  font-family: inherit;
  font-size: 1rem;
  font-weight: 800;
  cursor: pointer;
  transition: transform 0.15s, box-shadow 0.15s, opacity 0.15s;
}

.pu2-vocab-nav-prev {
  background: #fff;
  color: #475569;
  border: 2px solid #E2E8F0;
  box-shadow: 0 4px 10px rgba(0,0,0,0.05);
}
.pu2-vocab-nav-prev:not(:disabled):hover { transform: translateY(-2px); }

.pu2-vocab-nav-next {
  background: linear-gradient(140deg, #34D399, #10B981);
  color: #fff;
  box-shadow: 0 8px 20px rgba(16,185,129,0.35), 0 1px 0 rgba(255,255,255,0.4) inset;
}
.pu2-vocab-nav-next:not(:disabled):hover { transform: translateY(-2px) scale(1.02); }
.pu2-vocab-nav-next:not(:disabled):active { transform: scale(0.96); }

.pu2-vocab-nav-prev:disabled,
.pu2-vocab-nav-next:disabled {
  background: #F1F5F9;
  color: #94A3B8;
  border-color: transparent;
  cursor: not-allowed;
  box-shadow: none;
  opacity: 0.85;
}

/* Toast (no-audio warning) */
.pu2-toast {
  position: fixed;
  left: 50%;
  bottom: 24px;
  transform: translateX(-50%) translateY(20px);
  background: #1F2937;
  color: #fff;
  padding: 12px 20px;
  border-radius: 50px;
  font-size: 0.95rem;
  font-weight: 600;
  box-shadow: 0 12px 28px rgba(0,0,0,0.32);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s, transform 0.25s;
  z-index: 9999;
  max-width: 90vw;
  text-align: center;
}
.pu2-toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* Section tabs polish */
.pu2-section-tabs {
  margin-bottom: 18px;
}

/* ─── Papers Section (Home Dashboard) ────────────────────── */
.subject-header.papers-hdr {
  background: linear-gradient(135deg, #fff7d6 0%, #ffd370 100%);
}
.subject-header.papers-hdr .subj-name { color: #5b3a00; }
.subject-header.papers-hdr .subj-sub  { color: #b07f00; }

.module-btn.pp-mod {
  background: linear-gradient(135deg, #fff7d6 0%, #ffe9b8 100%);
  border: 2px solid #ffd370;
  box-shadow: 0 3px 0 #f4b53a, 0 2px 8px rgba(0,0,0,0.07);
  color: #5b3a00;
}
.module-btn.pp-mod .m-label { color: #5b3a00; }
.module-btn.pp-mod:hover    { background: linear-gradient(135deg, #fff2c0 0%, #ffe1a0 100%); }
.module-btn.pp-mod:active   { transform: scale(0.92) translateY(2px); }

/* ─── Life Section (生活: 人民币 / 时间 / 应用题) ─────── */
.subject-header.life-hdr {
  background: linear-gradient(135deg, #14B8A6 0%, #0E7490 100%);
}
.subject-header.life-hdr .subj-name { color: #FFFFFF; }
.subject-header.life-hdr .subj-sub  { color: rgba(255,255,255,0.85); }

.module-btn.lf-mod {
  background: linear-gradient(135deg, #CCFBF1 0%, #A5F3FC 100%);
  border: 2px solid #5EEAD4;
  box-shadow: 0 3px 0 #14B8A6, 0 2px 8px rgba(20,184,166,0.18);
  color: #134E4A;
}
.module-btn.lf-mod .m-label { color: #134E4A; }
.module-btn.lf-mod:hover    { background: linear-gradient(135deg, #B6F5EB 0%, #8EE7F0 100%); }
.module-btn.lf-mod:active   { transform: scale(0.92) translateY(2px); }

/* Life screen tab active color */
#life-screen .tab-btn.active {
  background: linear-gradient(135deg, #14B8A6, #0E7490);
  box-shadow: 0 4px 12px rgba(14,116,144,0.35);
}

/* Life display (currency / clock / wordprob) */
.life-display {
  font-size: 2.6rem;
  font-weight: 700;
  text-align: center;
  color: #0E7490;
  letter-spacing: 1px;
  line-height: 1.35;
  margin-bottom: 10px;
  background: linear-gradient(135deg, #ECFEFF 0%, #CCFBF1 100%);
  border-radius: var(--radius-md);
  padding: 22px 16px;
  border: 2px dashed #5EEAD4;
}

.life-clock-display {
  font-size: 1.8rem;
  line-height: 1.5;
}

.life-stem {
  font-size: 1.25rem;
  font-weight: 600;
  text-align: left;
  color: var(--text);
  line-height: 1.7;
  margin-bottom: 14px;
  background: #F0FDFA;
  border-left: 5px solid #14B8A6;
  border-radius: var(--radius-sm);
  padding: 18px 18px 18px 20px;
}

.life-progress {
  text-align: center;
  font-size: 0.92rem;
  color: var(--text-soft);
  margin-bottom: 12px;
  font-weight: 600;
}

.lf-mod:hover { background: #ECFEFF; }

@media (max-width: 600px) {
  .life-display      { font-size: 2rem; padding: 18px 12px; }
  .life-clock-display{ font-size: 1.45rem; }
  .life-stem         { font-size: 1.05rem; padding: 14px 14px 14px 16px; }
}

@media (max-width: 400px) {
  .life-display      { font-size: 1.7rem; }
  .life-clock-display{ font-size: 1.25rem; }
  .life-stem         { font-size: 1rem; }
}

@media (max-width: 360px) {
  .cards-grid { grid-template-columns: repeat(2, 1fr); gap: 8px; }
}

@media (max-width: 420px) {
  .tab-btn { font-size: 0.82rem; padding: 9px 6px; }
  .tab-bar  { gap: 5px; }
}