JSFiddle - React, Tailwind, and code Playground

HTML

<script>
function change_size(options) {
    
    var elem = document.getElementsByTagName('embed')[0];
    var new_width = 300;
    var new_height = 300;
    var wh = get_window_size();
    new_width = wh[0];
    new_height = wh[1];
    elem.style.width = new_width+'px';
    elem.style.height = new_height+'px';
    
}
    
function get_window_size(options) {
    
    if (document.body && document.body.offsetWidth) {
     winW = document.body.offsetWidth;
     winH = document.body.offsetHeight;
}
if (document.compatMode=='CSS1Compat' &&
    document.documentElement &&
    document.documentElement.offsetWidth ) {
     winW = document.documentElement.offsetWidth;
     winH = document.documentElement.offsetHeight;
}
if (window.innerWidth && window.innerHeight) {
    
     winW = window.innerWidth;
     winH = window.innerHeight;
}
    return [winW, winH];
}
</script>

<embed src="http://flash-test.net/relog.swf" style="width: 100px; height: 100px; background-color: #eee;">
<a href="#" id="" onclick="change_size(); return false;">Поменять размер</a>

CSS

body {
    overflow: hidden;
    margin: 0;
    padding: 0;
}