@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in {
    opacity: 0;
    animation: fadeInUp 1s forwards;
}

.fade-in-img {
    opacity: 0;
    animation: fadeInUp 1s forwards;
}

ul.tarjetas li:nth-child(1) {
    animation: fadeInUp 1s 0.3s forwards;
}
ul.tarjetas li:nth-child(2) {
    animation: fadeInUp 1s 0.6s forwards;
}
ul.tarjetas li:nth-child(3) {
    animation: fadeInUp 1s 0.9s forwards;
}