.galeria{
    display: flex;
    width:100%;
    height: 300px;
}
.galeria img{
    width: 0px;
    flex-grow: 1;
    object-fit: cover;
    filter: brightness(80%);
    transition: .7s ease;
}
.galeria img:hover{
    width: 800px;
    opacity: 1;
    filter: brightness(100%)
}