Код:

<style>
/*Быстроплюсы для Топика!*/
div .post-rating p a {
    text-align: center;
    outline: 1px solid transparent;
    font-weight: 700;
    background: url(https://upforme.ru/uploads/001a/f0/7d/2/466540.png  ) no-repeat center;
     background-size:36px auto;
     position:relative;
    z-index:100;
    width: 36px;
    height: 36px;
    text-align:center;
    font-size: 12px !important;
    display: inline-block;
    vertical-align: middle;
    line-height: 34px;
    letter-spacing: -.1px;
}
.noNull:before{content: "+";
    display: inline-block;
    margin-left: -1px;
    font-size: 9px;
    letter-spacing: 0!important;
}
.punbb .post-rating p {
   padding: 0 !important;
}
</style>

<script>
    'use strict';
 
// --- ОБЩИЕ ВСПОМОГАТЕЛЬНЫЕ ФУНКЦИИ ---
 
// Получает ID постов из указанного DOM-контекста
function getPostIds(scope = document) {
    // Работаем только на странице топика
    if (!$('#pun-viewtopic').length) return [];
    
    const postElements = $(scope).find('div.post');
    return postElements.map(function() {
        const id = $(this).attr('id');
        if (id && id.startsWith('p')) {
            return id.slice(1);
        }
    }).get();
}
 
// --- ЧАСТЬ 1: БЫСТРОПЛЮСЫ ---
 
// Отслеживание уже обработанных постов (для избежания дублирования)
const processedPostsForPlus = new Set();
 
// Обновляет отображение цифры рейтинга и управляет классом noNull
function setDigit(th) {
    var d = parseInt(th.innerHTML);
    if (d > 0) $(th).addClass('noNull');
    else $(th).removeClass('noNull');
    th.innerHTML = d;
}
 
// Сохранение оригинального alert для восстановления после голосования
var Busy = window.alert;
 
// Обработка клика по кнопке "плюса": отправка запроса, обновление рейтинга и мини-профиля
function setPlus(sel) {
    // Работаем только на странице топика
    if (!$('#pun-viewtopic').length) return;
    
    window.alert = null;
    var a = sel.prop('href');
    var pid = a.match(/\?id=(\d+)/)[1];
 
    var uid = sel.parents('.post').find('.pl-email a[href*="profile.php?"]').prop('href');
    if (uid) uid = uid.match(/\?id=(\d+)$/)[1];
    var v = a.match(/&v=(\d+)/)[1] == 0 ? -1 : 1;
    $('#post-' + pid + '-vote').hide();
 
    $.get(a + '&format=json', function(data) {
        if (data.error && data.error.message) {
            // Ошибка обрабатывается без уведомлений — только внутренняя логика
        } else if (data.delta) {
            if(data.response !== undefined) {
                $('#p' + pid + ' .post-rating a').text(data.response);
                setDigit($('#p' + pid + ' .post-rating a')[0]);
            } else {
                var oldRating = parseInt($('#p' + pid + ' .post-rating a').text()) || 0;
                var newRating = oldRating + data.delta;
                $('#p' + pid + ' .post-rating a').text(newRating);
                setDigit($('#p' + pid + ' .post-rating a')[0]);
            }
 
            // Обновление мини-профиля автора и текущего пользователя
            var $res = $('.pl-email a[href$="profile.php?id=' + uid + '"]').parents('.post').find('.pa-respect');
            var $pos = $('.pl-email a[href$="profile.php?id=' + UserID + '"]').parents('.post').find('.pa-positive');
 
            function replaceRating(sel, v, revert) {
                var html = $(sel).html(),
                    delta = v;
                if (revert) delta = delta > 0 ? -1 : 1;
                if (v > 0) {
                    html = html.replace(/\[\+(\d+)\//g, function(str, p1) {
                        return '[+' + (parseInt(p1) + delta) + '/';
                    });
                } else {
                    html = html.replace(/\/-(\d+)\]/g, function(str, p1) {
                        return '/-' + (parseInt(p1) - delta) + ']';
                    });
                }
                $(sel).html(html);
            }
            if ($res.html().indexOf('[') != -1) {
                $res.each(function() { replaceRating(this, v); });
                $pos.each(function() { replaceRating(this, v); });
                if (Math.abs(data.delta) == 2) {
                    v = v > 0 ? -1 : 1;
                    $res.each(function() { replaceRating(this, v, 1); });
                    $pos.each(function() { replaceRating(this, v, 1); });
                }
            } else {
                var d0 = $res.find('span:not(.fld-name)').html(),
                    p0 = $pos.find('span:not(.fld-name)').html();
                var d1 = parseInt(d0) + v;
                if (p0) {
                    var p1 = parseInt(p0) + v;
                }
                if (d1 && d1 > 0) {
                    d1 = '+' + d1;
                }
                if (p1 && p1 > 0) {
                    p1 = '+' + p1;
                }
                $res.find('span:not(.fld-name)').html(d1);
                if (p0) $pos.find('span:not(.fld-name)').html(p1);
            }
 
            // Генерация события для обновления списка "Спасибо" при лайке
            if(v === 1) {
                document.dispatchEvent(new CustomEvent('vote:happened', {
                    detail: { pid: pid, type: 'thank' }
                }));
            }
        }
        setTimeout(function() {window.alert = Busy;},1300);
    })
    .fail(function(xhr, status, error) {
        setTimeout(function() {window.alert = Busy;},1300);
    });
}
 
// Обёртка для вызова setPlus из onclick
window.BR = function(th) {
    // Работаем только на странице топика
    if (!$('#pun-viewtopic').length) return;
    
    var lnk = $(th).parents('.post-box').find('.post-vote>p>a');
    setPlus(lnk);
};
 
// Скрывает все вновь добавленные элементы .post-vote
function hideAllNewPostVotes(scope = document) {
    // Работаем только на странице топика
    if (!$('#pun-viewtopic').length) return;
    
    $(scope).find('.post-vote[id^="post-"]').each(function() {
        var postId = this.id.replace('post-', '');
        var postRatingLink = $(`.post#p${postId} .post-rating p a`);
        if(postRatingLink.length) {
             $(this).hide();
        }
    });
}
 
// Назначает обработчики для кнопок "плюса" в указанной области
function applyPlusHandlers(scope = document) {
    // Работаем только на странице топика
    if (!$('#pun-viewtopic').length) return;
    
    $(scope).find('.post .post-rating p a').each(function() {
        if (!this.hasAttribute('data-plus-handler')) {
             this.setAttribute("onclick", "BR(this)");
             setDigit(this);
 
             var postVoteLinkSelector = $(this).parents('.post').attr('id');
             if(postVoteLinkSelector) {
                 var pid = postVoteLinkSelector.slice(1);
                 var postVoteLink = $('#post-' + pid + '-vote');
                 if(postVoteLink.length) {
                      postVoteLink.hide();
                 }
             }
             this.setAttribute('data-plus-handler', 'true');
        }
    });
    hideAllNewPostVotes(scope);
}
 
// --- ЧАСТЬ 2: СПИСОК ПОБЛАГОДАРИВШИХ (API-ЛОГИКА) ---
 
// Отслеживание постов, для которых уже запрашивались "спасибо"
const processedPostsForThanks = new Set();
 
// Отслеживание ID постов, для которых выполняется запрос (для дедупликации)
const pendingUpdates = new Set();
 
// Вставка списка благодаривших в пост
function insertThanksList(postId, thankersListHtml) {
    // Работаем только на странице топика
    if (!$('#pun-viewtopic').length) return;
    
    if (!thankersListHtml) {
        return;
    }
 
    var postBox = $('.post#p' + postId + ' .post-box');
    if (postBox.length && postBox.find('.postVoters').length === 0) {
        var html = '<div class="postVoters"><strong><i><font color ="#13355e">Сказали спасибо</font></i>:</strong> ' + thankersListHtml + '</div>';
        postBox.append(html);
        processedPostsForThanks.add(postId);
    } else {
        if(postBox.length === 0) {
            var postElement = $('.post#p' + postId);
            if(postElement.length && postElement.find('.postVoters').length === 0) {
                var html = '<div class="postVoters"><strong><i><font color ="#13355e">Сказали спасибо</font></i>:</strong> ' + thankersListHtml + '</div>';
                postElement.append(html);
                processedPostsForThanks.add(postId);
            }
        } else {
            postBox.find('.postVoters').html('<strong><i><font color ="#13355e">Сказали спасибо</font></i>:</strong> ' + thankersListHtml);
        }
    }
}
 
// Обработка ответа API: группировка и вставка благодаривших
function processVotes(data) {
    // Работаем только на странице топика
    if (!$('#pun-viewtopic').length) return;
    
    if (!data || !data.response) {
        const postIdsFromRequest = currentFetchRequestIds || [];
        postIdsFromRequest.forEach(id => processedPostsForThanks.add(id));
        currentFetchRequestIds = null;
        return;
    }
 
    const votesByPost = {};
    data.response.forEach(item => {
        const postId = item.post_id;
        if (item.votes && Array.isArray(item.votes)) {
            item.votes.forEach(vote => {
                if (vote.value === '1') {
                    if (!votesByPost[postId]) {
                        votesByPost[postId] = [];
                    }
                    votesByPost[postId].push(vote);
                }
            });
        }
    });
 
    Object.keys(votesByPost).forEach(postId => {
        const votesForThisPost = votesByPost[postId];
        let thankersHtml = '';
        votesForThisPost.forEach((vote, index) => {
            thankersHtml += '<a href="/profile.php?id=' + vote.user_id + '">' + vote.username + '</a>';
            if (index < votesForThisPost.length - 1) {
                thankersHtml += ', ';
            }
        });
        insertThanksList(postId, thankersHtml);
    });
 
    Object.keys(votesByPost).forEach(id => processedPostsForThanks.add(id));
    data.response.forEach(item => {
        if (!processedPostsForThanks.has(item.post_id)) {
            processedPostsForThanks.add(item.post_id);
        }
    });
}
 
// Выполнение API-запроса для получения списка благодаривших
let currentFetchRequestIds = null;
 
function fetchVotesForPosts(postIds) {
    // Работаем только на странице топика
    if (!$('#pun-viewtopic').length) return;
    
    if (!postIds || postIds.length === 0) {
        postIds.forEach(id => pendingUpdates.delete(id));
        return;
    }
 
    const apiParams = {
        method: 'post.getVotesByPosts',
        post_id: postIds.join(','),
        fields: 'post_id,user_id,username,value,datetime',
        sort_dir: 'desc'
    };
 
    currentFetchRequestIds = [...postIds];
 
    return $.get('/api.php', apiParams, function(data) {
        processVotes(data);
    }, 'json')
    .fail(function(xhr, status, error) {
        postIds.forEach(id => processedPostsForThanks.add(id));
        currentFetchRequestIds = null;
    });
}
 
// Планирование обновления списка "спасибо" для новых постов
function scheduleUpdate(scope = document) {
    // Работаем только на странице топика
    if (!$('#pun-viewtopic').length) return;
    
    requestAnimationFrame(() => {
        const newPostIds = getPostIds(scope).filter(id => !processedPostsForThanks.has(id));
        if (newPostIds.length > 0) {
            const idsToRequest = newPostIds.filter(id => !pendingUpdates.has(id));
            if (idsToRequest.length > 0) {
                idsToRequest.forEach(id => pendingUpdates.add(id));
                fetchVotesForPosts(idsToRequest).always(() => {
                    idsToRequest.forEach(id => pendingUpdates.delete(id));
                });
            }
        }
    });
}
 
// Объединённая функция резервного обновления (раз в секунду)
function combinedBackupUpdate() {
    // Работаем только на странице топика
    if (!$('#pun-viewtopic').length) return;
    
    applyPlusHandlers(document);
    scheduleUpdate(document);
}
 
// --- ИНИЦИАЛИЗАЦИЯ И ПОДПИСКИ НА СОБЫТИЯ ---
 
// Инициализация при загрузке DOM
$(function() {
    // Работаем только на странице топика
    if (!$('#pun-viewtopic').length) return;
    
    $('.post .post-rating p a').each(function() {
        this.setAttribute("onclick", "BR(this)");
        setDigit(this);
        var postVoteLinkSelector = $(this).parents('.post').attr('id');
        if(postVoteLinkSelector) {
            var pid = postVoteLinkSelector.slice(1);
            var postVoteLink = $('#post-' + pid + '-vote');
            if(postVoteLink.length && $(this).hasClass('noNull')) {
                postVoteLink.hide();
            }
        }
        this.setAttribute('data-plus-handler', 'true');
    });
 
    scheduleUpdate(document);
});
 
// Подписка на событие добавления нового поста (например, через AJAX)
document.addEventListener('pun_post', function(e) {
    // Работаем только на странице топика
    if (!$('#pun-viewtopic').length) return;
    
    var scope = e.detail?.post || document.body;
    applyPlusHandlers(scope);
    scheduleUpdate(scope);
});
 
// Подписка на собственное событие после успешного лайка
document.addEventListener('vote:happened', function(e) {
    // Работаем только на странице топика
    if (!$('#pun-viewtopic').length) return;
    
    if (e.detail && e.detail.pid && e.detail.type === 'thank') {
        var pid = e.detail.pid;
        var specificPostScope = $('#p' + pid);
        if(specificPostScope.length) {
            if (!pendingUpdates.has(pid)) {
                pendingUpdates.add(pid);
                fetchVotesForPosts([pid]).always(() => {
                    pendingUpdates.delete(pid);
                });
            }
        }
    }
});
 
// Подписка на глобальное AJAX-событие для отслеживания лайков от любых пользователей
$(document).on('ajaxSuccess', function(e, xhr, data) {
    // Работаем только на странице топика
    if (!$('#pun-viewtopic').length) return;
    
    if (data && data.url && /relation\.php.*[&?]v=(\d+)/.test(data.url)) {
        const match = data.url.match(/id=(\d+)/);
        const pid = match ? match[1] : null;
        const voteType = data.url.match(/v=(\d+)/)?.[1];
 
        if (pid && voteType === '1') {
            if (!pendingUpdates.has(pid)) {
                pendingUpdates.add(pid);
                fetchVotesForPosts([pid]).always(() => {
                    pendingUpdates.delete(pid);
                });
            }
        }
    }
});
 
// Наблюдатель за изменениями DOM для динамических постов
const observer = new MutationObserver(function(mutationsList) {
    // Работаем только на странице топика
    if (!$('#pun-viewtopic').length) return;
    
    let shouldUpdate = false;
    let relevantScope = document.body;
 
    for (let mutation of mutationsList) {
        if (mutation.type === 'childList') {
            for (let node of mutation.addedNodes) {
                if (node.nodeType === 1) {
                    if (node.classList && node.classList.contains('post')) {
                        relevantScope = node;
                        shouldUpdate = true;
                        break;
                    } else if (node.querySelector && node.querySelector('div.post')) {
                        relevantScope = node;
                        shouldUpdate = true;
                        break;
                    } else {
                        const nestedPosts = node.querySelectorAll && node.querySelectorAll('div.post');
                        if (nestedPosts && nestedPosts.length > 0) {
                            relevantScope = node;
                            shouldUpdate = true;
                            break;
                        }
                    }
                }
            }
            if (shouldUpdate) break;
        }
    }
 
    if (shouldUpdate) {
        requestAnimationFrame(() => {
            applyPlusHandlers(relevantScope);
            hideAllNewPostVotes(relevantScope);
            scheduleUpdate(relevantScope);
        });
    }
});
 
observer.observe(document.body, { childList: true, subtree: true });
 
// Резервный таймер для обновления раз в секунду
const backupInterval = setInterval(combinedBackupUpdate, 1000);
</script>

Добавлена проверка if (!$('#pun-viewtopic').length) return; в следующие места:

    ✅ getPostIds() - не получает ID постов вне топика
    ✅ setPlus() - не обрабатывает клики вне топика 
    ✅ BR() - обёртка для кликов
    ✅ hideAllNewPostVotes() - не скрывает элементы вне топика
    ✅ applyPlusHandlers() - не назначает обработчики вне топика
    ✅ insertThanksList() - не вставляет списки вне топика
    ✅ processVotes() - не обрабатывает ответы вне топика
    ✅ fetchVotesForPosts() - не делает запросы вне топика
    ✅ scheduleUpdate() - не планирует обновления вне топика
    ✅ combinedBackupUpdate() - не обновляет вне топика
    ✅ $(function() {...}) - не инициализирует вне топика
    ✅ document.addEventListener('pun_post', ...) - не реагирует на события вне топика
    ✅ document.addEventListener('vote:happened', ...) - не обрабатывает лайки вне топика
    ✅ $(document).on('ajaxSuccess', ...) - не слушает AJAX вне топика
    ✅ MutationObserver callback - не наблюдает за изменениями вне топика

Код:

 <!-- Тёмная тема для Classic DarkCyan v.1-->
<style>
/* ===== Переключатель темы ===== */
#html-header {
    position: relative;
}
.StyleSwitch {
    height: 20px;
    width: 20px;
    position: absolute;
    z-index: 1000;
    right: 5px;
    top: 50px;
    border-radius: 50%;
    cursor: pointer;
    box-shadow: 0 0 10px rgba(0,0,0,.7);
    transition: .1s ease;
}
.StyleSwitch:hover { opacity: .8; }
.StyleSwitch.St {
    background: #2DA7A7 url(https://forumstatic.ru/files/0016/a6/f8/22564.png) center center no-repeat!important;
    background-size: 16px!important;
}
.StyleSwitch.My {
    background: #1a6b6b url(https://forumstatic.ru/files/0016/a6/f8/90261.png) center center no-repeat!important;
    background-size: 16px!important;
}

/* ===== Тёмная тема Classic DarkCyan ===== */
body.dark-theme {
    background: #1a2a2a;
    color: #c8e0e0;
}
body.dark-theme #pun {
    background: #1e2e2e;
    box-shadow: 0 0 15px rgba(0, 200, 200, .1);
}
body.dark-theme #pun-title,
body.dark-theme #pun-title .container {
    background-color: #1a5a5a;
    background-image: linear-gradient(to bottom, rgba(0,0,0,.3) 0%, rgba(0,0,0,0) 70%);
}
body.dark-theme #pun-title h1 span {
    color: #e0f5f5;
    text-shadow: 0 2px 4px rgba(0,0,0,.5);
}
body.dark-theme #pun-navlinks {
    background: rgba(0,0,0,.6);
    box-shadow: inset rgba(0,0,0,.8) 0 1px 5px, rgba(0,200,200,.05) 0 -1px 0;
}
body.dark-theme #pun-navlinks .container {
    color: #b0d8d8;
}
body.dark-theme #pun-navlinks li a {
    color: #c8e8e8;
    text-shadow: 0 1px 3px rgba(0,0,0,.5);
}
body.dark-theme #pun-navlinks li a:hover {
    background: rgba(45, 167, 167, .2);
    color: #80e0e0;
    text-shadow: 0 0 8px rgba(100, 220, 220, .5);
}
body.dark-theme #pun-navlinks .isactive a {
    background: rgba(45, 167, 167, .35);
    box-shadow: inset rgba(0,200,200,.15) 0 1px 4px;
}
body.dark-theme #pun-ulinks .container {
    background: #1a3a3a;
    background-image: linear-gradient(to bottom, rgba(255,255,255,.05) 0%, rgba(255,255,255,0) 100%);
    border-bottom-color: #2a5a5a;
}
body.dark-theme #pun-ulinks li a {
    color: #70c8c0;
}
body.dark-theme #pun-ulinks li a:hover {
    background: rgba(45, 167, 167, .15);
    box-shadow: inset rgba(0,0,0,.2) 0 1px 3px;
}
body.dark-theme .punbb .main .container,
body.dark-theme .punbb .post .container {
    background: #223333;
    border-color: #2a5050;
    color: #c0d8d8;
}
body.dark-theme .punbb .section .container,
body.dark-theme .punbb .modmenu .container,
body.dark-theme .punbb .post-body,
body.dark-theme .punbb .post-links,
body.dark-theme .punbb td.tc2,
body.dark-theme .punbb td.tc3,
body.dark-theme .punbb .formal fieldset .post-box,
body.dark-theme #viewprofile li strong,
body.dark-theme #viewprofile li div,
body.dark-theme #setmods dd,
body.dark-theme .punbb .info-box,
body.dark-theme .punbb #pun-main .info-box .legend {
    background: #1e3030;
    color: #b8d0d0;
}
body.dark-theme #pun-stats h2,
body.dark-theme .punbb .main h1,
body.dark-theme .punbb .main h2,
body.dark-theme #pun-debug h2,
body.dark-theme .punbb-admin #pun-admain h2 {
    background-color: #1a5a5a;
    border-color: #2a7a7a;
    color: #d0f0f0;
    background-image: linear-gradient(to bottom, rgba(255,255,255,.08) 0%, rgba(255,255,255,0) 100%);
    text-shadow: 0 1px 2px rgba(0,0,0,.6);
    box-shadow: inset rgba(100,220,220,.1) 0 1px 0;
}
body.dark-theme #pun-stats h2 span,
body.dark-theme .punbb .main h1 span,
body.dark-theme .punbb .main h2 span {
    color: #d0f0f0;
}
body.dark-theme .punbb a,
body.dark-theme .punbb a:link,
body.dark-theme .punbb a:visited {
    color: #50b8b0;
}
body.dark-theme .punbb a:hover,
body.dark-theme .punbb a:focus,
body.dark-theme .punbb a:active {
    color: #70e0d8;
    text-decoration: underline;
}
body.dark-theme .punbb li.isactive a,
body.dark-theme .punbb li.isactive a:link,
body.dark-theme .punbb li.isactive a:visited {
    color: #a0d0d0;
}
body.dark-theme .punbb td,
body.dark-theme .punbb fieldset,
body.dark-theme #viewprofile ul,
body.dark-theme #profilenav ul,
body.dark-theme .punbb .post .post-body,
body.dark-theme .punbb .post h3 span,
body.dark-theme .post-links ul,
body.dark-theme .post-links,
body.dark-theme .usertable table,
body.dark-theme .punbb .container,
body.dark-theme .punbb .post-body,
body.dark-theme .post h3,
body.dark-theme #pun-title {
    border-color: #2a5050;
}
body.dark-theme .punbb th {
    background-color: #1a3a3a;
    background-image: linear-gradient(to bottom, rgba(255,255,255,.06) 0%, rgba(255,255,255,0) 100%);
    border-bottom-color: #2a5a5a !important;
    color: #a0c8c8;
}
body.dark-theme .punbb .post h3 {
    background: #1a3030;
    border-color: #2a5050;
}
body.dark-theme .punbb .post h3 span {
    background-color: transparent !important;
    color: #b0d0d0;
    border-left-color: #2a5050;
}
body.dark-theme .punbb .quote-box,
body.dark-theme .punbb .code-box {
    border-color: #2a5a5a;
    background-color: #1a2a2a;
    color: #c0d8d8;
    box-shadow: 0 1px 6px rgba(0,0,0,.3);
}
body.dark-theme .punbb .quote-box cite,
body.dark-theme .punbb .code-box .legend,
body.dark-theme .punbb .spoiler-box > div {
    background: #1e3a3a;
    background-image: linear-gradient(to bottom, rgba(255,255,255,.05) 0%, rgba(255,255,255,0) 100%);
    border-bottom-color: #2a5a5a;
    color: #70b8b0;
}
body.dark-theme .punbb .post-content .blockcode,
body.dark-theme .punbb .post-content blockquote {
    background-color: #182828;
}
body.dark-theme .punbb .code-box {
    background-color: #162626;
    color: #d0e8e8;
}
body.dark-theme form .button,
body.dark-theme input[type="submit"] {
    color: #a0d8d0;
    background: #1a3a3a;
    border-color: #2a5a5a;
    background-image: linear-gradient(to bottom, rgba(255,255,255,.08) 0%, rgba(255,255,255,0) 100%);
    text-shadow: 0 1px 2px rgba(0,0,0,.4);
    box-shadow: 0 1px 3px rgba(0,0,0,.3);
}
body.dark-theme form .button:hover,
body.dark-theme input[type="submit"]:hover {
    background: #1e4a4a;
    box-shadow: inset rgba(100,220,220,.1) 0 100px 0, 0 1px 3px rgba(0,0,0,.3);
}
body.dark-theme form .button:disabled,
body.dark-theme input[type="submit"]:disabled {
    background: #0e1e1e;
    color: #556;
    box-shadow: none;
}
body.dark-theme .punbb input[type=password],
body.dark-theme .punbb input[type=text],
body.dark-theme .punbb input[type=search],
body.dark-theme .punbb select,
body.dark-theme .punbb textarea {
    background: #162626;
    border-color: #2a4a4a !important;
    color: #b8d0d0;
}
body.dark-theme .punbb input[type=password]:hover,
body.dark-theme .punbb input[type=text]:hover,
body.dark-theme .punbb input[type=search]:hover,
body.dark-theme .punbb textarea:hover,
body.dark-theme .punbb select:hover,
body.dark-theme .punbb input[type=password]:focus,
body.dark-theme .punbb input[type=text]:focus,
body.dark-theme .punbb input[type=search]:focus,
body.dark-theme .punbb textarea:focus,
body.dark-theme .punbb select:focus {
    border-color: #3a7a7a !important;
}
body.dark-theme #viewprofile li,
body.dark-theme #setmods dl {
    background: #1a3030;
    background-image: linear-gradient(to bottom, rgba(255,255,255,.04) 0%, rgba(255,255,255,0) 100%);
    color: #b0c8c8;
}
body.dark-theme #viewprofile h2 span,
body.dark-theme #profilenav h2 span,
body.dark-theme .punbb legend span {
    background-color: #1e3030;
    color: #70c8c0;
}
body.dark-theme #profilenav li a:hover {
    background: rgba(45, 167, 167, .15);
    box-shadow: inset rgba(0,0,0,.15) 0 1px 3px;
    color: #70e0d8;
}
body.dark-theme #profilenav li.isactive a {
    background: rgba(45, 167, 167, .12);
    box-shadow: inset rgba(100,200,200,.08) 0 1px 3px;
}
body.dark-theme .punbb .divider {
    border-color: #2a4a4a transparent transparent;
}
body.dark-theme li#onlinelist {
    border-top-color: #2a4a4a;
}
body.dark-theme li#onlinelist div {
    border-top-color: #2a4a4a;
    color: #a0b8b8;
}
body.dark-theme #pun-announcement h2 span {
    color: #c0e0e0;
    border-bottom-color: #2a5a5a;
}
body.dark-theme #pun-announcement .container {
    border-bottom-color: rgba(255,255,255,.05) !important;
}
body.dark-theme #pun-crumbs1 p.container {
    background: #1e2e2e;
    border-top-color: #2a4a4a;
    color: #a0b8b8;
}
body.dark-theme #pun-crumbs2 .container {
    background: #1e2e2e;
    border-bottom-color: #2a4a4a;
    color: #a0b8b8;
}
body.dark-theme #pun-about .container {
    background: #1e2e2e;
    border-top-color: #2a4a4a;
}
body.dark-theme #pun-status .container {
    background: #1e3030;
    border-bottom-color: #2a4a4a;
    color: #a0b8b8;
}
body.dark-theme hr {
    border-color: #2a4a4a;
}
body.dark-theme .punbb .modmenu .container {
    background-color: transparent;
    color: #a0b8b8;
}
body.dark-theme .post-links li a:hover {
    background-color: rgba(45, 167, 167, .12);
    border-color: #2a5a5a;
    color: #70d8d0 !important;
}
body.dark-theme #pun-pagelinks {
    color: #b8d0d0;
}
body.dark-theme #pun-pagelinks a:active,
body.dark-theme #pun-pagelinks a:focus {
    background-color: #2a5a5a;
    color: #e0f5f5;
}
body.dark-theme .punbb p.container.crumbs a:hover {
    background-color: rgba(45, 167, 167, .12);
    border-color: #2a5a5a;
}
body.dark-theme #paginator {
    background-color: #1a2a2a !important;
    border-color: #2a5a5a !important;
    box-shadow: 0 5px 10px rgba(0,0,0,.5) !important;
}
body.dark-theme #paginator a:hover {
    background-color: #1e4a4a !important;
}
body.dark-theme .punbb .post .post-rating .container,
body.dark-theme .punbb .post-vote .container {
    background-color: rgba(0, 40, 40, .4) !important;
    border-color: transparent !important;
}
body.dark-theme .punbb .post-sig dt {
    border-top-color: #2a4a4a;
}
body.dark-theme #profile-signature ul {
    border-color: #2a5a5a;
}
body.dark-theme .user-agent [class^="ua-icon-"]:before {
    filter: grayscale(.2) brightness(1.3);
}
body.dark-theme fieldset {
    background: #1a3030 !important;
    border-color: #2a5a5a;
}
body.dark-theme .punbb .post.new-ajax {
    background-color: rgba(0, 80, 80, .15);
}
body.dark-theme #keyboard-span input {
    background-color: rgba(255,255,255,.03);
    border-color: #2a4a4a;
    color: #c0d8d8;
}
body.dark-theme #profilenav li.isactive {
    background-color: rgba(255,255,255,.05);
    border-color: rgba(0,0,0,.1);
}
body.dark-theme .post-content table td {
    border-color: #2a5a5a !important;
}
body.dark-theme ul.punbb-dropdown ul {
    background-color: #1a3030;
}
body.dark-theme #isk {
    background: rgba(0,0,0,.3);
    border-color: transparent;
}
body.dark-theme .post-content kbd {
    background: #162626 !important;
    border-color: transparent !important;
}
body.dark-theme .punbb #MyBookmarks {
    background: #1e2e2e;
}
body.dark-theme .punbb #MyBookmarks li.BookmarkL {
    border-bottom-color: #2a5a5a !important;
}
body.dark-theme .punbb #MyBookmarks span.scrl {
    background-color: #162626;
    color: #b0c8c8;
}
body.dark-theme .punbb .editBookmark h1,
body.dark-theme .punbb .main #MyBookmarks h2,
body.dark-theme .punbb .main #MyBookmarks h1 {
    background-color: #1a3a3a !important;
    color: #b8d0d0 !important;
}
body.dark-theme .punbb .editBookmark .container {
    background-color: #1e2e2e;
}
body.dark-theme .punbb #navextra1:hover > a,
body.dark-theme .punbb #pun-navlinks ul ul {
    background-color: #1a4a4a !important;
    border-color: #2a5a5a;
    box-shadow: none !important;
}
body.dark-theme #pun-navlinks ul ul li:hover {
    background-color: #1e5a5a !important;
}
body.dark-theme .tooltipsy {
    background-color: #1a3a3a !important;
}
body.dark-theme .pun-modal .modal-inner {
    background: #1e2e2e;
}
body.dark-theme .punbb div[id$="-area"] {
    background-color: #162626 !important;
    border-color: rgba(255,255,255,.05) !important;
}
body.dark-theme .punbb fieldset {
    border-color: rgba(255,255,255,.08);
}
body.dark-theme .category th,
body.dark-theme #pun-viewforum .main th,
body.dark-theme #pun-searchtopics .main th {
    color: #a0c8c8;
}
body.dark-theme #table-area td {
    background-color: #1a3a3a;
    border-color: #2a5a5a !important;
}
body.dark-theme #table-area td.selected {
    background-color: #2a6a6a;
    border-color: #1a3a3a !important;
}
body.dark-theme #poll-special h1 {
    background: #1a5a5a;
}
body.dark-theme #pun-index .main h2,
body.dark-theme #pun-searchtopics .main h1,
body.dark-theme #pun-viewforum .main h1 {
    background: transparent;
    color: #c0e0e0;
}
body.dark-theme #pun-main h3 > a {
    background: #1a3a3a !important;
    border-radius: 10px !important;
    padding: 0 7px 3px !important;
}
body.dark-theme #setmods dl,
body.dark-theme .punbb .post h3 {
    background-color: rgba(0,0,0,.15);
    color: #a0b8b8;
}
body.dark-theme #pun-redirect {
    background: #1e2e2e;
}
body.dark-theme #form-buttons td:hover {
    background-color: #162626;
}
body.dark-theme #pun-userlist th {
    background: #1a3a3a !important;
}
body.dark-theme #pun-announcement h2 > span {
    color: #c0e0e0;
    border-bottom-color: #2a5a5a;
}
body.dark-theme #pun-debug h2,
body.dark-theme #pun-stats h2,
body.dark-theme .punbb .main h1,
body.dark-theme .punbb .main h2,
body.dark-theme .punbb-admin #pun-admain h2 {
    border-color: #2a7a7a;
}
body.dark-theme li.pa-online {
    border-left-color: #30a0a0;
}
body.dark-theme .adcontainer {
    border-color: #2a5a5a !important;
}
body.dark-theme .publication {
    color: #70c8c0 !important;
    text-shadow: none !important;
}
body.dark-theme .slider_wrap figcaption {
    background: rgba(10, 20, 20, .9) !important;
}
body.dark-theme .post-author .pa-online,
body.dark-theme .post-author:not(.online) .pa-author .acchide {
    background: #3a8a70 !important;
}
body.dark-theme #pun-searchform .main input[type=search] {
    background-color: rgba(0,0,0,.3);
}
body.dark-theme .input-button[disabled] {
    opacity: .5 !important;
}
body.dark-theme #pun-edit a:not([disabled]) {
    color: #5a9a90;
}
body.dark-theme form li#navblock-2 a:hover,
body.dark-theme a[href*="/pun/viewtopic"]:not([disabled]) {
    background-color: rgba(26, 58, 58, .4);
}
body.dark-theme #profilenav ul {
    border-bottom-color: #2a5a5a;
}
body.dark-theme #profile-right li:not(:last-child) {
    border-bottom-color: #2a4a4a;
}
body.dark-theme #pun-redirect .info a {
    color: #3a8a8a;
}
body.dark-theme .punbb .closedatafield + a,
body.dark-theme .punbb .closedatafield + strong > a {
    color: #888 !important;
}
body.dark-theme #pun-ulinks {
    background: #162626;
}
body.dark-theme .punbb .stickytext + a,
body.dark-theme .punbb .stickytext + strong > a,
body.dark-theme .punbb .stickytext + .closedatafield + a,
body.dark-theme .punbb .stickytext + .closedatafield + strong > a {
    color: #c8a0a0 !important;
}
body.dark-theme #pun-searchtopics.punbb .tcl a {
    color: #80b8b8 !important;
}
body.dark-theme .quote-box .quote-after.q-resize-1,
body.dark-theme #messages .post .quote-box.answer-box blockquote:not(.blockquote-toggle)::after {
    background: linear-gradient(to bottom, transparent 0%, #1a3a3a 80%, #1a3a3a 100%) !important;
}
body.dark-theme #pun-messages .main #messages tr:hover {
    background-color: rgba(255,255,255,.03);
}
body.dark-theme .usersname a,
body.dark-theme #onlinelist a,
body.dark-theme li.pa-author > a {
    filter: brightness(1.15) contrast(1.1);
}
body.dark-theme #pun-rules .main .html-box > p,
body.dark-theme #pun-regrules .main .html-box > p,
body.dark-theme #pun-register .main .info-box {
    background: #2a2a3a;
    border-color: #4a4a5a;
}
body.dark-theme #pun-rules font[color=grey],
body.dark-theme #pun-regrules font[color=grey] {
    color: #e0645a;
}
body.dark-theme #pun-rules span[style="color:red"],
body.dark-theme #pun-regrules span[style="color:red"] {
    color: #8bc34a !important;
}
body.dark-theme #pun-rules .main .html-box div > p,
body.dark-theme #pun-regrules .main .html-box div > p,
body.dark-theme #pun-rules .main .html-box span > a,
body.dark-theme #pun-regrules .main .html-box span > a {
    background: rgba(22, 38, 38) !important;
    border-color: rgba(0,0,0,.4);
}
body.dark-theme #pun-regrules .main p.formsubmit {
    background: transparent;
    border-color: transparent;
}
body.dark-theme .slider_wrap {
    box-shadow: 0 7px 10px rgba(0,0,0,.5) !important;
}
body.dark-theme #pun-pagelinks a:focus,
body.dark-theme #pun-pagelinks a:active {
    background-color: rgba(45, 167, 167, .5);
}
body.dark-theme [id^="tooltipsy"] {
    max-width: 90vw;
}
body.dark-theme .post-content .code-box .linenums li.L1,
body.dark-theme .post-content .code-box .linenums li.L3,
body.dark-theme .post-content .code-box .linenums li.L5,
body.dark-theme .post-content .code-box .linenums li.L7,
body.dark-theme .post-content .code-box .linenums li.L9 {
    background: transparent !important;
}
body.dark-theme .code-box .linenums .str { color: #6ab88a; }
body.dark-theme .code-box .linenums .kwd { color: #7a90b0; }
body.dark-theme .code-box .linenums .com { color: #c08a8a; }
body.dark-theme .code-box .linenums .typ { color: #c08090; }
body.dark-theme .code-box .linenums .lit { color: #60b0a8; }
body.dark-theme .code-box .linenums .clo,
body.dark-theme .code-box .linenums .opn,
body.dark-theme .code-box .linenums .pun { color: #c0a060; }
body.dark-theme .code-box .linenums .tag { color: #60b8d0; }
body.dark-theme .code-box .linenums .atn { color: #a880b8; }
body.dark-theme .code-box .linenums .atv { color: #90b870; }
body.dark-theme .code-box .linenums .pln { color: #c8d8d8; }

/* ===== Подсветка ссылок в постах ===== */
body.dark-theme .punbb .post-content p a {
    background: rgba(45, 167, 167, .08);
    border-radius: 3px;
    padding: 2px;
}
body.dark-theme .punbb .post-content p a:hover {
    color: #70e0d8;
}

/* ===== "Сказали спасибо" ===== */
body.dark-theme .postVoters strong {
    background: #1a4a4a;
    padding: 2px 6px;
    border-radius: 4px;
    color: #80d0c8;
    border: 1px solid #2a6a6a;
}

/* ===== Треугольники ===== */
body.dark-theme .post .post-body::before {
    border-color: transparent #1e3030 transparent transparent !important;
}
body.dark-theme .post .post-body::after {
    border-color: transparent #2a5050 transparent transparent !important;
}

/* ===== Checkbox/Radio ===== */
body.dark-theme input[type=checkbox],
body.dark-theme input[type=radio] {
    border-color: rgba(255,255,255,.1);
    background-color: rgba(0,0,0,.15);
}
body.dark-theme input[type=radio]:hover,
body.dark-theme input[type=checkbox]:hover {
    border-color: rgba(255,255,255,.25);
}
body.dark-theme input[type=radio]:checked:after {
    background: #c0d8d8;
}
body.dark-theme input[type=checkbox]:focus,
body.dark-theme input[type=radio]:focus {
    border-color: #c0d8d8;
}
body.dark-theme input[type=checkbox]:checked::after {
    color: #e0f0f0;
}

/* ===== Scrollbar ===== */
body.dark-theme *::-webkit-scrollbar {
    -webkit-appearance: none;
}
body.dark-theme *::-webkit-scrollbar:vertical {
    width: 8px;
}
body.dark-theme *::-webkit-scrollbar:horizontal {
    height: 8px;
}
body.dark-theme *::-webkit-scrollbar-thumb {
    background-color: rgba(80, 180, 170, .4);
    border-radius: 10px;
}
body.dark-theme *::-webkit-scrollbar-thumb:hover {
    background-color: rgba(100, 210, 200, .5);
}
body.dark-theme *::-webkit-scrollbar-thumb:active {
    background-color: rgba(120, 230, 220, .5);
}
body.dark-theme *::-webkit-scrollbar-track {
    background-color: rgba(255,255,255,.03);
    border-radius: 10px;
}
body.dark-theme *::-webkit-scrollbar-corner {
    background-color: transparent;
}

/* ===== Placeholder ===== */
body.dark-theme ::placeholder {
    color: rgba(200, 224, 224, .6);
}

/* ===== Post colors ===== */
body.dark-theme .post span[style="color: red"] { color: #ff8989 !important; }
body.dark-theme .post span[style="color: green"] { color: #6ab88a !important; }
body.dark-theme .post span[style="color: blue"] { color: #50a8e0 !important; }
body.dark-theme .post span[style="color: maroon"] { color: #c08090 !important; }
body.dark-theme .post span[style="color: olive"] { color: #d8d870 !important; }
body.dark-theme .post span[style="color: navy"] { color: #9090d8 !important; }

/* ===== Rating hearts ===== */
body.dark-theme div .post-rating p a {
    background: url(https://i.ibb.co/1Gx3mJ9Q/gray-heart.png) no-repeat center !important;
    background-size: 36px auto !important;
    filter: brightness(1.2) contrast(1.1);
}

/* ===== Animations ===== */
@keyframes fadebg-dark {
    0% { background-color: rgba(0, 80, 80, .15); }
    100% { background-color: #1e2e2e; }
}
body.dark-theme .punbb .post.new-ajax {
    animation: fadebg-dark 3s 3s ease-out forwards;
}

/* ===== Mobile ===== */
@media screen and (max-width: 540px) {
    body.dark-theme #pun .punbb #pun-main td {
        border-bottom-color: #2a4a4a !important;
    }
    body.dark-theme #pun-ulinks,
    body.dark-theme #pun-navlinks .container li a {
        filter: brightness(0.85);
    }
    body.dark-theme .punbb #pun-navlinks {
        top: -38px !important;
        background-color: #162626;
        border-bottom: 1px solid #162626 !important;
    }
    body.dark-theme .punbb .category .container,
    body.dark-theme .punbb .forum .container {
        border-top-color: #2a5a5a !important;
    }
    body.dark-theme #pun .punbb .post-author,
    body.dark-theme #pun .punbb .post-author ul {
        background-color: rgba(0,0,0,.1) !important;
    }
    body.dark-theme #pun .punbb .post h3 span {
        background-color: transparent !important;
        border-top: none !important;
    }
    body.dark-theme .punbb .post h3 {
        border-top-color: rgba(0,0,0,.1) !important;
    }
    body.dark-theme #paginator {
        border-color: rgba(255,255,255,.15) !important;
    }
    body.dark-theme #paginator td {
        border-color: rgba(255,255,255,.15) !important;
    }
    body.dark-theme #profile-right li {
        background-color: rgba(0,0,0,.15) !important;
        border-left: none !important;
    }
    body.dark-theme #pun .punbb tr.isticky div.icon,
    body.dark-theme #pun .punbb tr.inewisticky div.icon {
        filter: brightness(1.5) contrast(1.2);
        opacity: .7;
    }
}
</style>

<script type="text/javascript">
(function () {
    /* ===== Функция включения тёмной темы ===== */
    function setStyle () {
        $('.StyleSwitch').removeClass('St').addClass('My');
        $('.StyleSwitch').attr('title','Стандартный стиль Classic DarkCyan');
        $('body').addClass('dark-theme');
    }

    /* ===== Добавляем кнопку в HTML ===== */
    $('#html-header').prepend('<span class="StyleSwitch St" title="Тёмная тема Classic DarkCyan"></span>');
    $('.StyleSwitch').tipsy({fade: true, gravity: 'nw'});

    if($getCookie('StyleSwitch')) { setStyle(); }

    /* ===== Событие клика для включения ===== */
    $('.StyleSwitch.St').live('click', function () {
        $setCookie('StyleSwitch','My',30*3600*24*30*1000);
        setStyle();
    });

    /* ===== Событие клика для выключения ===== */
    $('.StyleSwitch.My').live('click', function () {
        $deleteCookie('StyleSwitch');
        $('.StyleSwitch').addClass('St').removeClass('My');
        $('.StyleSwitch').attr('title','Тёмная тема Classic DarkCyan');
        $('body').removeClass('dark-theme');
    });
})();
</script>
<!-- Конец тёмной темы Classic DarkCyan v.1--->

Код:

<!-- Тёмная тема для Classic DarkCyan v.2-->
<style>
/* ===== Переключатель темы ===== */
#html-header {
    position: relative;
}
.StyleSwitch {
    height: 20px;
    width: 20px;
    position: absolute;
    z-index: 1000;
    right: 5px;
    top: 50px;
    border-radius: 50%;
    cursor: pointer;
    box-shadow: 0 0 10px rgba(0,0,0,.7);
    transition: .1s ease;
}
.StyleSwitch:hover { opacity: .8; }
.StyleSwitch.St {
    background: #426B9A url(https://forumstatic.ru/files/0016/a6/f8/22564.png) center center no-repeat!important;
    background-size: 16px!important;
}
.StyleSwitch.My {
    background: #6996CA url(https://forumstatic.ru/files/0016/a6/f8/90261.png) center center no-repeat!important;
    background-size: 16px!important;
}
 
/* ===== Треугольники (только для тёмной темы) ===== */
body.dark-theme .post .post-body::before {
    border-color: transparent #4a5b70 transparent transparent !important;
}
body.dark-theme .post .post-body::after {
    border-color: transparent #2d3748 transparent transparent !important;
}
 
/* ===== "Сказали спасибо" (только для тёмной темы) ===== */
body.dark-theme .postVoters strong {
    background: #5a7a8f;
    padding: 2px 4px;
    border-radius: 4px;
    color: #e8f0f5;
}
 
/* ===== Подсветка ссылок в постах (только для тёмной темы) ===== */
body.dark-theme .punbb .post-content p a {
    background: rgba(100,150,200,0.15);
    border-radius: 3px;
    padding: 2px;
}
body.dark-theme .punbb .post-content p a:hover { 
    color: #80c8e0;
}
</style>
 
<script type="text/javascript">
(function () {
    var style = 'https://forumstatic.ru/files/001a/f0/7d/73291.css?v=45'; // Ссылка на внешний CSS
    style = '<link rel="stylesheet" id="StyleAdd" type="text/css" href="'+style+'"/>';
 
    /* ===== Функция включения тёмного стиля ===== */
    function setStyle () {
        $('link[rel="stylesheet"]:last').after(style);
        $('.StyleSwitch').removeClass('St').addClass('My');
        $('.StyleSwitch').attr('title','Стандартный стиль');
        $('body').addClass('dark-theme');
    }
 
    /* ===== Добавляем кнопку в HTML ===== */
    $('#html-header').prepend('<span class="StyleSwitch St" title="Затемненный стиль"></span>');
    $('.StyleSwitch').tipsy({fade: true, gravity: 'nw'});
 
    if($getCookie('StyleSwitch')) { setStyle (); }
 
    /* ===== Событие клика по кнопке для включения ===== */
    $('.StyleSwitch.St').live('click', function () {
        $setCookie('StyleSwitch','My',30*3600*24*30*1000);
        setStyle ();
    });  
 
    /* ===== Событие клика по кнопке для выключения ===== */
    $('.StyleSwitch.My').live('click', function () {
        $('link#StyleAdd').remove();
        $deleteCookie('StyleSwitch');
        $('.StyleSwitch').addClass('St').removeClass('My');
        $('.StyleSwitch').attr('title','Затемненный стиль');
        $('body').removeClass('dark-theme');
    });
})();
</script>
<!-- Конец тёмной темы Classic DarkCyan v.2--->