网页任意变动div的大小，我这里只设置了大 中 小 三种大小，可以根据需要自己设置任何 大小的div，实现无级变动
<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport"
content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
</head>
<body>
<div style="text-align: center;">
<button onclick="playPause()">播放/暂停</button>
<button onclick="makeBig()">大</button>
<button onclick="makeNormal()">中</button>
<button onclick="makeSmall()">小</button>
<br/>
<video id="video1" controls preload="none" width="420%" height="100%" data-setup="{}" autoplay="autoplay">
<source src="images/test.mp4">
</video>
</div>
<script>
var myvideo=document.getElementById("video1")
function playPause() {
if (myvideo.paused == true) {
myvideo.play();
} else {
myvideo.pause();
}
}
function makeBig() {
myvideo.width=560;
}
function makeSmall() {
myvideo.width=320;
}
function makeNomal() {
myvideo.width=420;
}
</script>
</body>
</html>