TamperMonkeyDenSpoilerScript.js

// ==UserScript==
// @name         Den Spoilers
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  Spoiler functionality
// @author       You
// @match        http://www.tgdmb.com/phpBB3/*
// @match        http://tgdmb.com/phpBB3/*
// @icon         https://www.google.com/s2/favicons?sz=64&domain=tgdmb.com
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    for(let content of document.getElementsByClassName("content")) {
        content.innerHTML = content.innerHTML.replaceAll(/\[spoiler\](.*?)\[\/spoiler\]/gs,
                                                         "\<style\>"+
                                                         "	summary \{"+
                                                         "		user\-select\: none;"+
                                                         "		outline\: 0 \!important;"+
                                                         "	\}"+
                                                         ""+
                                                         "	summary \.bbctitle \{"+
                                                         "		font\-weight\: bold;"+
                                                         "		padding\-left\: 5px;"+
                                                         "		cursor\: pointer;"+
                                                         "	\}"+
                                                         ""+
                                                         "	summary\:\:\-webkit\-details\-marker \{"+
                                                         "		display\: none"+
                                                         "	\}"+
                                                         ""+
                                                         "	summary\:\:before \{"+
                                                         "		float\: left;"+
                                                         "		padding\-left\: 1px;"+
                                                         "		font\-family\: \"FontAwesome\";"+
                                                         "		content\: \"\\f055\";"+
                                                         "		cursor\: pointer;"+
                                                         "	\}"+
                                                         ""+
                                                         "	details\[open\] summary\:\:before \{"+
                                                         "		content\: \"\\f056\";"+
                                                         "	\}"+
                                                         ""+
                                                         "	details\.bbcspoiler\[open\] summary\:\:after \{"+
                                                         "		content\: attr\(title\-open\);"+
                                                         "		font\-weight\: bold;"+
                                                         "		cursor\: pointer;"+
                                                         "	\}"+
                                                         ""+
                                                         "	details\.bbcspoiler\:not\(\[open\]\) summary\:\:after \{"+
                                                         "		content\: attr\(title\-close\);"+
                                                         "		font\-weight\: bold;"+
                                                         "		cursor\: pointer;"+
                                                         "	\}"+
                                                         ""+
                                                         "	details \.bbccontent \{"+
                                                         "		margin\-top\: 3px;"+
                                                         "		margin\-bottom\: 15px;"+
                                                         "		margin\-left\: 15px;"+
                                                         "	\}"+
                                                         "\</style\>"+
                                                         "<details class='bbcspoiler'>"+
                                                         "<summary title-open='Collapse view' title-close='Display'><span class='bbctitle'></span></summary>"+
                                                         "<div class='bbccontent'>$1</div>"+
                                                         "</details>"
                                                        );
    }
})();