.sliderbg {
    background-color: rgba(0,0,0,0.5);
    position: fixed;
    left: 0;
    top: 0;
    width: 100vw;
    height: 100vh;
    z-index: 3;
}
.slider {
    position: fixed;
    width: 80vw;
    bottom: 1cm;
    left: 10vw;
    display: flex;
    flex-direction: row;
    align-items: center;
    z-index: 4;
}
.slider .left {
    width: 32px;
    height: 32px;
    background-image: url(../image/slider-left.png);
}
.slider .right {
    width: 32px;
    height: 32px;
    background-image: url(../image/slider-right.png);
}
.slider .middle {
    flex: 1;
    background-image: url(../image/slider-bar.png);
}
.slider .dot {
    background-color: skyblue;
    border: 1px solid gray;
    box-shadow: 0 0 1ex rgba(0,0,0,0.5);
    border-radius: 16px;
    width: 32px;
    height: 32px;
    text-align: center;
    line-height: 32px;
    position: relative;
    user-select: none;
    -moz-user-select: none;
    cursor: pointer;
}