gallery1.css

/*global*/
*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
.title {
    text-align: center;
    font-size: 4vmin;
    color: #313157
}
html,body {
    background: #e8d5ea;
    padding: 10px;
}
img {
    max-width: 100%;
    height: auto;
    vertical-align: middle;
    display: inline-block;
}
.grid-wrapper > div{
    display: flex;
    justify-content: center;
    align-items: center;
}
.grid-wrapper > div > img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 5px;
}
.grid-wrapper {
    display: grid;
    grid-gap: 10px;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    grid-auto-rows: 200px;
    grid-auto-flow: dense;
}
.grid-wrapper .wide {
    grid-column: span 2;
}
.grid-wrapper .tall {
    grid-row: span 2;
}
.grid-wrapper .big {
    grid-column: span 2;
    grid-row: span 2;
}
/*animations*/ 
img {
    transition: transform .3s ease;
}
img:hover {
    transform:scale(1.1);
}