html, body {
    background-color: black;
    margin: 0;
    padding: 0;
    width: 100%;
    height: 100%;
    background-image: url('../image/bg.png');
}

.videoContainer {
    position: absolute;
    width: 100%;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
}
.bgVideo {
    width: 100%;
    display: none;
}
.bgVideo.active {
    display: block;
}

.smallVideo, .tinyVideo, .timerVideo {
    position: absolute;
}
.smallVideo video, .tinyVideo video, .timerVideo video {
    width: 100%;
    height: 100%;
}
.timerVideo {
    display: none;
}


.ballContainer {
    position: fixed;
    width: 500px;
    height: 70px;
    bottom: 10px;
    left: 50%;
    line-height: 50px;
    transform: translateX(-50%);
    border-radius: 10px;
    text-align: center;
    margin-left: -60px;
}
.ballContainer img {
    width: 50px;
}
#ball-1, #ball-2, #ball-3, #ball-4, #ball-5, #ball-6, #ball-sum {
    display: inline-block;
    vertical-align: top;
    margin: 10px 5px;
}
#ball-sum {
    width: 75px;
    height: 50px;
    line-height: 50px;
    vertical-align: middle;
    background-image: url('../image/sum_not_started.png');
    background-size: auto 75px;
    background-position-y: -12px;
    font-weight: bolder;
    transition-duration: 200ms;
}
#ball-sum.active {
    background-image: url('../image/sum_started.png');
    transition-duration: 200ms;
}
#ball-sum.done {
    background-image: url('../image/sum_result.png');
    transition-duration: 200ms;
}
#ball-sum img {
    margin-top: 12px;
    width: auto;
    height: 25px;
}

.roundId {
    background-image: url('../image/round_bg.png');
    width: 88px;
    height: 52px;
    position: fixed;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    margin-left: 240px;
    text-align: center;
}
.roundId img {
    margin-top: 18px;
    width: auto;
    height: 15px;
}

.mute-btn {
    position: fixed;
    top: 7px;
    right: 7px;
    width: 50px;
    height: 50px;
    padding: 10px;
    cursor: pointer;
}
.mute-btn img {
    width: 100%;
    height: 100%;
}