Greasy Fork

Hi, nice script, I didn't realize that the shitty glow was a Youtube "feature", I tought it was Firefox glitching. In Firefox is not even smoothed, so you just see dim, huge pixels flashing over the background.
By the way, the script can't work on Greasemonkey as it doesn't have the GM_addStyle function anymore
Here's a possible solution:

(function() {
'use strict';
if(typeof GM_addStyle !== 'function'){
var GM_addStyle = function addStyle(css) {// GM_addStyle redefined as explained here: https://9to5answer.com/gm_addstyle-equivalent-in-tampermonkey
const style = document.getElementById("GM_addStyleBy8626") || (function() {
const style = document.createElement('style');
style.type = 'text/css';
style.id = "GM_addStyleBy8626";
document.head.appendChild(style);
return style;
})();
const sheet = style.sheet;
sheet.insertRule(css, (sheet.rules || sheet.cssRules || []).length);
}
}
GM_addStyle
(`#cinematics.ytd-watch-flexy {
display: none;
}
`)

})();