body {
    text-align: center;
    height: 600px;
    width: 724px;
    margin: 0;
}

#gallery {
    border: 4px ridge #4464c4;
    height: 408px;
    /*width: 716px;*/
    width: 656px;
    margin-left: 30px;
    margin-top: 20px;
    background-image: url(assets/wall.jpg);
    background-size: cover;
    overflow-y: scroll;
    display: flex;
    justify-content: center;
    flex-direction: column;
}