#snow {
    width: 100%;
    height: 100%;
    position: absolute;
    top: 0px;
    left: 0px;
    z-index: 2;
}

#christmas {
    width: 100%;
    height: 100%;
    position: absolute;
    top: 0px;
    left: 0px;
    background-image: url('../images/christmas_background.jpg');
    background-repeat: no-repeat;
    background-size: cover;
    background-position: center top;
    background-attachment: fixed;
    z-index: 0;
    opacity: 0.15;
}