html,
body {
    margin: 0;
    padding: 0;
    width: 100%;
    height: 100%;
}

* {
    margin: 0;
    padding: 0;
}

.realtime-view-video-box {
    padding: 14px;
    width: 100%;
    height: 100%;
    box-sizing: border-box;
    color: #fff;
}

.realtime-view-video-box video {
    width: 100%;
    height: 100%;
}