.big-video {
    position: relative;
    overflow: hidden;
}
.btn-play {
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    cursor: pointer;
    z-index: 2;
}
.btn-play img {
    width: 60px;
}
/*视频模式下整个容器可点击，鼠标指针变成手型*/
.big-video.allUploadBox.video-mode{
    cursor: pointer;
}