<!DOCTYPE html>
<html>
<head>
<title></title>
<style type="text/css">
.block {
position: absolute;
opacity: 0;
z-index: 999999999;
}
</style>
</head>
<body>
<div class="block"></div>
<video controls="controls" style="width: 100%;" class="video" src="1.mkv"></video>
<script type="text/javascript">
"use strict";
let video = document.querySelector(".video");
const getStyle = window.getComputedStyle;
document.querySelector(".block").style = `
width: ${getStyle(video).getPropertyValue("width")};
height: ${getStyle(video).getPropertyValue("height")};
`;
</script>
</body>
</html>