userscript that loads custom css on any webpage
// ==UserScript==
// @name Custom CSS Loader
// @namespace ,
// @include https://*/*
// @include http://*/*
// @author ogmicco
// @version 1.0
// @description userscript that loads custom css on any webpage
// @license MIT
// @resource CUSTOM_CSS LINK_TO_CSS_HERE
// @grant GM_addStyle
// @grant GM_getResourceText
// @match *://*/*
// @run-at document-start
// ==/UserScript==
var cssTxt = GM_getResourceText ("CUSTOM_CSS");
console.log(cssTxt);
GM_addStyle (cssTxt);