css中怎么添加视频教程

.video-container {
   width: 640px;
   height: 360px;
} 

.video-controls {
   background-color: #333;
   color: #fff;
   padding: 10px;
} 

<video>
   <source src="video.mp4" type="video/mp4">
   <track kind="subtitles" src="subtitles.vtt" srclang="en" label="English">
</video> 

.video-player {
   border: 1px solid #ccc;
   background-color: #f1f1f1;
   width: 700px;
   height: 400px;
}