.bookshelf {
    margin:0;
    padding: 0;
    background: #EEE;
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    align-items: center;
}
.bookshelf div {
    margin:12px;
    padding:0 20px 0 20px;
    transition: all .25s ease-in-out;
}
.bookshelf div:hover {transform: scale(1.05);}
.bookshelf img { height: 250px }
.bookshelf .book0 {width:0;padding:0}