.flashcard {
  width: 100%;
  max-width: 760px;
  height: 340px;
  margin: 0 auto;
  cursor: pointer;
  position: relative;
}

.card-inner {
  position: relative;
  width: 100%;
  height: 100%;
  border-radius: 0;
  overflow: hidden;
  border: 3px solid var(--border);
  box-shadow: var(--shadow);
  background: #fff;
}

.card-front,
.card-back {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 16px;
  padding: 28px;
  color: var(--text);
  transition: transform 0.35s ease, opacity 0.35s ease;
  will-change: opacity, transform;
}

.card-front {
  transform: translateY(0);
  opacity: 1;
  z-index: 2;
  background: var(--primary);
}

.card-back {
  transform: translateY(18px);
  opacity: 0;
  z-index: 1;
  background: #fff;
}

.flashcard.flipped .card-front {
  transform: translateY(-20px) !important;
  opacity: 0 !important;
  pointer-events: none;
}

.flashcard.flipped .card-back {
  transform: translateY(0) !important;
  opacity: 1 !important;
  pointer-events: auto;
}

.card-front h2,
.card-back h2 {
  margin: 0;
  font-size: clamp(2rem, 2.8vw, 3rem);
  letter-spacing: 0.02em;
}

.hint {
  color: #333;
  font-size: 0.92rem;
  font-weight: 700;
}

.meaning {
  font-size: 1.75rem;
  font-weight: 800;
  color: #111;
}

.usage,
.sentence {
  font-size: 1rem;
  line-height: 1.6;
  color: var(--muted);
}

.sentence {
  border-left: 4px solid #111;
  padding-left: 14px;
}