#forwardLayer, #backLayer{
    position: absolute; 
    top: 0; 
    left: 0; 
    width: 100%; 
    height: 100%;
    -webkit-box-align:center;
    -webkit-box-pack:center;
    display:-webkit-box; 
    z-index: 9999;
}
#forwardLayer i, #backLayer i{
    transition: all 1s ease;
}
#forwardLayer i{
    position: absolute; right: 100px;
}
#backLayer i{
    position: absolute; left: 100px;
}
#forwardLayer i.active{
    right: 20px;
}
#backLayer i.active{
    left: 20px;
}