body {
  font-family: 'Segoe UI', sans-serif;
}

#flashcard {
  min-height: 150px;
  border-radius: 15px;
  cursor: pointer;
}

.card-side {
  transition: opacity 0.3s ease;
}

.d-none {
  display: none !important;
}
.flip-card {
  background-color: transparent;
  width: 100%;
  max-width: 300px;
  height: 180px;
  perspective: 1000px;
  cursor: pointer;
}

.flip-card-inner {
  position: relative;
  width: 100%;
  height: 100%;
  text-align: center;
  transition: transform 0.6s;
  transform-style: preserve-3d;
}

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

.flip-card-front,
.flip-card-back {
  position: absolute;
  width: 100%;
  height: 100%;
  backface-visibility: hidden;
  display: flex;
  justify-content: center;
  align-items: center;
  border-radius: 15px;
  background: #444;
  color: white;
  padding: 20px;
  box-shadow: 0 0 10px rgba(0,0,0,0.4);
}

.flip-card-back {
  transform: rotateY(180deg);
  background: #222;
}