*{
    padding: 0px;
    margin: 0px;
    box-sizing: border-box;
}

._fotos{
    display: grid;
    /* grid-template-columns: minmax(200px, fit-content); */
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
}

._fotos img{
    width: 100%;
    height: 100%;
}

img::after{
    content: 'ok';
    position: absolute;
    left: 0px;
    top: 0px;
}