/* ═══════════════════════════════════════════════════
   CET-4/6 Learning App — Flashcards Styles
   ═══════════════════════════════════════════════════ */

.flashcard-container {
  perspective: 1200px;
  display: flex;
  justify-content: center;
  padding: 10px 0;
}

.flashcard {
  width: 100%;
  max-width: 480px;
  min-height: 280px;
  position: relative;
  cursor: pointer;
  transform-style: preserve-3d;
  transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.flashcard.flipped {
  transform: rotateY(180deg);
}

.flashcard-front,
.flashcard-back {
  position: absolute;
  inset: 0;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  border-radius: var(--radius-lg);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 32px 24px;
  box-shadow: var(--shadow-lg);
  border: 2px solid var(--border);
  min-height: 280px;
}

.flashcard-front {
  background: linear-gradient(135deg, var(--bg-card) 0%, var(--bg-card-hover) 100%);
  z-index: 2;
}

.flashcard-back {
  background: linear-gradient(135deg, #EEF2FF 0%, #E8F0FE 100%);
  transform: rotateY(180deg);
}
[data-theme="dark"] .flashcard-back {
  background: linear-gradient(135deg, #1E293B 0%, #1E3A5F 100%);
}

.flashcard-word {
  font-size: 2.2rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 8px;
  text-align: center;
  word-break: break-word;
}

.flashcard-phonetic {
  font-size: 1rem;
  color: var(--text-secondary);
  margin-bottom: 4px;
  font-style: italic;
}

.flashcard-translation {
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 12px;
  text-align: center;
}

.flashcard-example {
  font-size: 0.9rem;
  color: var(--text-secondary);
  text-align: center;
  margin-top: 12px;
  line-height: 1.5;
  padding: 0 8px;
}
.flashcard-example .en { font-style: italic; color: var(--text-primary); }
.flashcard-example .cn { color: var(--text-muted); font-size: 0.85rem; }

.flashcard-synonyms {
  margin-top: 10px;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  justify-content: center;
}
.flashcard-synonyms .badge {
  background: rgba(74, 144, 217, 0.1);
  color: var(--accent);
  border: none;
  font-size: 0.78rem;
}

.speak-btn {
  margin-top: 8px;
  font-size: 1.4rem;
  transition: transform var(--ease);
}
.speak-btn:hover { transform: scale(1.2); }

/* ─── Flashcard Controls ─── */
.flashcard-actions {
  display: flex;
  justify-content: center;
  gap: 20px;
  margin-top: 24px;
}

/* ─── Filter Dropdown ─── */
#vocabFilter {
  background: var(--bg-card);
  border: 1.5px solid var(--border);
  color: var(--text-primary);
  border-radius: var(--radius-sm);
  padding: 8px 12px;
  font-size: 0.85rem;
  font-family: var(--font-sans);
  cursor: pointer;
}

/* ─── Responsive ─── */
@media (max-width: 768px) {
  .flashcard {
    max-width: 100%;
    min-height: 240px;
  }
  .flashcard-front,
  .flashcard-back {
    min-height: 240px;
    padding: 24px 16px;
  }
  .flashcard-word { font-size: 1.6rem; }
  .flashcard-translation { font-size: 1.3rem; }
  .flashcard-actions { gap: 14px; }
  .flashcard-actions .btn { padding: 12px 20px; font-size: 0.85rem; }
}