.flip-card {
    width: 100vw;      /* Todo el ancho del iPhone */
    height: 100vh;     /* Todo el alto del iPhone */
    perspective: 2000px;
    margin: 0;         /* Sin bordes */
    overflow: hidden;  /* Evita recortes extraños */
}

.flip-card-inner {
    width: 100%;
    height: 100%;
    position: relative;
    transform-style: preserve-3d;
    transition: transform 1s ease;
}

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

.flip-face {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    background-size: cover;       /* Ajusta la imagen sin deformarla */
    background-position: center;  /* Centra la imagen */
}

.front {
    background-image: url('https://7cff2c54-f434-4020-b0ed-8290129d4304.filesusr.com/ugd/569216_b9b4d12c54ed45dbb46139f6857d698f.pdf');
}

.back {
    background-image: url('https://7cff2c54-f434-4020-b0ed-8290129d4304.filesusr.com/ugd/569216_07dc2c9d477b4cac8513a364a45c1d92.pdf');
    transform: rotateY(180deg);
}