.flip-card {
    perspective: 1000px;
}

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

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

.flip-front,
.flip-back {
    backface-visibility: hidden;
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
}

.flip-back {
    transform: rotateY(180deg);
}