要使视频播放器具有响应能力，请使用width属性并将其设置为100％
<!DOCTYPE html>
<html>
<head>
<meta name = "viewport" content="width=device-width, initial-scale=1.0">
<style>
video {
width: 100%;
height: auto;
}
</style>
</head>
<body>
<video width = "300" controls autoplay>
<source src = "/html5/foo.ogg" type = "video/ogg" />
<source src = "/html5/foo.mp4" type = "video/mp4" />
</video>
<p>To check the effect, you need to resize the browser.</p>
</body>
</html>