Let the video fill the browser to enhance the watching experience.
If the video in theater mode, click the full screen button will turn video in 21:9 ratio when your monitor also is 21:9 (Just support few webpage video, ex:Youtube)
将网页中的影片填满整个浏览器, 使观赏体验提升。
当影片处于剧院模式, 若再点击全萤幕的按钮且萤幕为21:9比例, 则会将影片转换为21:9. (目前只支援极少数网页影片, 例如:Youtube)
