/* flip the pane when hovered */
.flip-container:hover .flipper, .flip-container.hover .flipper {
    transform: rotateY(180deg);
}

/* flip speed goes here */
.flipper {
    transition: .8s;
    transform-style: preserve-3d;
    position: relative;
}
.flipper div{
    border-radius: 50%;
}
.flipper div img{
    width:100%;
    height: 100%;
    display: block;
}
/* hide back of pane during swap */
.front{
    position: relative;
}
.back {
    backface-visibility: hidden;
    position: absolute;
    top: 0;
    left: 0;
}

/* front pane, placed above back */
.front {
    z-index: 2;
    /* for firefox 31 */
    transform: rotateY(0deg);
}

/* back, initially hidden pane */
.back {
    transform: rotateY(180deg);
}

.flip-container:hover .flipper, .flip-container.hover .flipper, .flip-container.flip .flipper {
    transform: rotateY(180deg);
}

.vertical.flip-container {
    position: relative;
}

.vertical .back {
    transform: rotateX(180deg);
}

.vertical.flip-container .flipper {
    transform-origin: 100% 213.5px; /* half of height */
}

.vertical.flip-container:hover .flipper {
    transform: rotateX(-180deg);
}