Raw Source
nascent / Youtube - Remove Description Padding (Wider video, description and comments pane) 

// ==UserScript==
// @name           Youtube - Remove Description Padding (Wider video, description and comments pane)
// @namespace      youtube
// @author         nascent
// @description    Removes the padding for youtube descriptions allowing for less condensed wdesign and allowing for space for any extra buttons added by other scripts
// @icon           https://www.youtube.com/favicon.ico
// @icon64         https://www.youtube.com/favicon.ico
// @version        1
// @noframes
// @grant          GM_addStyle
// @include        https://www.youtube.com/*
// @updateURL https://openuserjs.org/meta/nascent/Youtube_-_Remove_Description_Padding_(Wider_video,_description_and_comments_pane).meta.js
// @downloadURL https://openuserjs.org/install/nascent/Youtube_-_Remove_Description_Padding_(Wider_video,_description_and_comments_pane).user.js
// @license GPL-3.0-or-later
// ==/UserScript==
(async function() {

    //--ytd-watch-flexy-max-player-width
    GM_addStyle(".ytd-app, ytd-watch-flexy[flexy] { --ytd-watch-flexy-max-player-width: unset !important; }");
})();