.youtubeBox { position: relative; margin: 0 auto; height: 422px; width: 750px; overflow: hidden;}.youtubeBox a { position: absolute; top: 0; left: 0; height: 422px; width: 750px; z-index: 2;}.modActionBar { position: absolute; left: 0; bottom: 0; width: 100px; height: 45px; z-index: 3;}.turnOffSound, .turnOnSound { background-image: url(//sla.ckcdn.com/2015/image/common/video_ad_btn.png); background-repeat: no-repeat;}.turnOffSound,.turnOnSound { cursor: pointer; display: block; margin: 10px auto 0; width: 20px; height: 18px; text-indent: -999em;}.turnOffSound { background-position: left -41px;}.turnOnSound { background-position: left -74px;} 關閉聲音
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