```javascript
(function () {
 const tabs = Array.from(document.querySelectorAll('.news-tab'));
 const filterOptions = Array.from(document.querySelectorAll('.news-filter-option'));
 const filterBtn = document.getElementById('news-filter-toggle');
 const filterPopover = document.getElementById('news-filter-popover');
 const sortBtn = document.getElementById('news-sort-toggle');
 const grid = document.querySelector('.post-grid');

if (!grid) {
 return;
 }

let cards = Array.from(grid.querySelectorAll('.post-card'));
 let sortDirection = sortBtn ? sortBtn.getAttribute('data-direction') || 'desc' : 'desc';

const setActiveFilter = (value) => {
 tabs.forEach(tab => tab.classList.toggle('is-active', tab.dataset.filter === value));
 filterOptions.forEach(option => option.classList.toggle('is-active', option.dataset.filter === value));
 };

const applyFilter = (value) => {
 cards.forEach(card => {
 const topic = card.dataset.topic || 'all';
 card.hidden = value !== 'all' && topic !== value;
 });
 };

const sortCards = (direction) => {
 const sortedCards = [...cards].sort((a, b) => {
 const aDate = new Date(a.dataset.date || 0);
 const bDate = new Date(b.dataset.date || 0);
 return direction === 'asc' ? aDate - bDate : bDate - aDate;
 });
 sortedCards.forEach(card => grid.appendChild(card));
 cards = sortedCards;
 };

tabs.forEach(tab => {
 tab.addEventListener('click', event => {
 event.preventDefault();
 const filterValue = tab.dataset.filter || 'all';
 setActiveFilter(filterValue);
 applyFilter(filterValue);
 });
 });

filterOptions.forEach(option => {
 option.addEventListener('click', () => {
 const filterValue = option.dataset.filter || 'all';
 setActiveFilter(filterValue);
 applyFilter(filterValue);
 if (filterPopover) {
 filterPopover.classList.remove('is-open');
 }
 if (filterBtn) {
 filterBtn.setAttribute('aria-expanded', 'false');
 }
 });
 });

if (filterBtn && filterPopover) {
 const closePopover = (event) => {
 if (!filterPopover.contains(event.target) && !filterBtn.contains(event.target)) {
 filterPopover.classList.remove('is-open');
 filterBtn.setAttribute('aria-expanded', 'false');
 document.removeEventListener('click', closePopover);
 document.removeEventListener('keydown', handleEscape, true);
 }
 };

const handleEscape = (event) => {
 if (event.key === 'Escape') {
 filterPopover.classList.remove('is-open');
 filterBtn.setAttribute('aria-expanded', 'false');
 document.removeEventListener('click', closePopover);
 document.removeEventListener('keydown', handleEscape, true);
 }
 };

filterBtn.addEventListener('click', (event) => {
 event.preventDefault();
 event.stopPropagation();
 const isOpen = filterPopover.classList.toggle('is-open');
 filterBtn.setAttribute('aria-expanded', String(isOpen));
 if (isOpen) {
 document.addEventListener('click', closePopover);
 document.addEventListener('keydown', handleEscape, true);
 } else {
 document.removeEventListener('click', closePopover);
 document.removeEventListener('keydown', handleEscape, true);
 }
 });
 }

if (sortBtn) {
 sortBtn.addEventListener('click', () => {
 sortDirection = sortDirection === 'desc' ? 'asc' : 'desc';
 sortBtn.setAttribute('data-direction', sortDirection);
 sortBtn.classList.toggle('is-asc', sortDirection === 'asc');
 sortCards(sortDirection);
 });
 }
})();
```