caption_filter_n_transfermation.css

body{
    padding: 1rem;
}
.gallery{
    display: grid;
    list-style-type: none;
    padding: 0;
    margin: 0;
    grid-gap: 1rem;
    grid-template-columns: repeat(auto-fit,minmax(300px,1fr));
    grid-auto-rows: 300px;
    grid-auto-flow: dense;
}
/*this is added*/
.gallery li figure{
    margin: 0;
    width: 100%;
    height: 100%;
    position: relative;
}
/* ---------------- */
.wide{
    grid-column: span 2;
}
.tall{
    grid-row: span 2;
}
img{
    width: 100%;
    height: 100%;
    display: block;
    object-fit: cover;
}


/* Add Here */
.gallery li figure{
    overflow: hidden;
}

.gallery img{
    filter: invert(25%);
    transform: scale(1.2);
    transition: all .3s ease-in-out;
}

.gallery figure figcaption{
    position: absolute;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    display: grid;
    align-content: end;
    color: #fff;
    text-shadow: 1px 1px 3px rgba(0,0,0,.5);
    padding-left: 2rem;
    opacity: 0;
    transition: opacity .3s ease-in-out;
}
.gallery figure:hover img{
    filter: invert(0);
    transform: scale(1);

}
.gallery figure:hover figcaption{
    opacity: 1;
}