body{
    margin : 0px;
    overflow: hidden;
    overflow-x: hidden;
    overflow-y: hidden;
}
#_skipBtn{
    background: url('./img/btn_skip.png') no-repeat;
    background-size: 100% 100%;
    width: 256px;
    height: 86px;
    left: 920px;
    top: 540px;
    position: absolute;
    z-index: 3;
    display: none;
}
#_skipBtn:hover{
    background: url('./img/btn_skip_over.png') no-repeat;
    background-size: 100% 100%;
    width: 256px;
    height: 86px;
    left: 920px;
    top: 540px;
    position: absolute;
    z-index: 3;
}
#_nextBalloon{
    background: url('./img/balloon_next.png') no-repeat;
    background-size: 100% 100%;
    width: 115px;
    height: 86px;
    left: 892px;
    top: 590px;
    position: absolute;
    display: none;
    z-index: 7;
}
#_lastBalloon{
    background: url('./img/balloon_last.png') no-repeat;
    background-size: 100% 100%;
    width: 115px;
    height: 86px;
    left: 892px;
    top: 590px;
    position: absolute;
    display: none;
    z-index: 7;
}