#content {
    position: relative;

}

#content img {
    position: absolute;
    top: 0;
    left: 0;
    z-index: 8;
    opacity: 0.0;
}

#content img.active {
    z-index: 10;
    opacity: 1.0;
}

#content img.last-active {
    z-index: 9;
}