.slider-img {
    background-image: url(../imagenes/Daniela-portada.png);
    background-size: cover;
    width: 40%; /* tamaño ideal */
    height: 100%;
    background-position: 0px -2vw;
    /* border-radius: 10px; */
    animation: animate 15s infinite; /* falto la s */
    
}

@keyframes animate {
    33% {
        background-image: url(../imagenes/daniela-paciente.png);
        background-size: cover;
    }
    66% {
        background-image: url(../imagenes/daniela-tools.png);
        background-size: cover;

    }
    100% {
        background-image: url(../imagenes/Daniela-portada.png);
        background-size: cover;
    }
    
}