.pack_title_img .play {
    width: 320px;
    height: 200px;
    position: absolute;
    background: url(/free-course/dev/product/www_v3/imgs/packClass/i-play.png) center 60px no-repeat;
}

.pack_title_img .play:hover {
    background: url(/free-course/dev/product/www_v3/imgs/packClass/i-play-hover.png);
}

.pack_know.free {
    width: 69px;
    height: 15px;
    background:  url(/free-course/dev/product/www_v3/imgs/packClass/i-free.png);
}