(function () {
	'use strict';

	var root = document.documentElement;
	var themeToggle = document.getElementById('themeToggle');

	if (themeToggle) {
		themeToggle.addEventListener('click', function () {
			var next = root.dataset.theme === 'dark' ? 'light' : 'dark';
			root.dataset.theme = next;
			try { localStorage.setItem('stg-site-theme', next); } catch (error) {}
		});
	}

	var revealEls = Array.prototype.slice.call(document.querySelectorAll('.reveal'));
	var revealTick = 0;

	function revealInViewport() {
		var viewportHeight = window.innerHeight || document.documentElement.clientHeight;
		revealEls.forEach(function (el) {
			if (el.classList.contains('visible')) return;
			var rect = el.getBoundingClientRect();
			if (rect.top < viewportHeight * 0.94 && rect.bottom > 0) el.classList.add('visible');
		});
	}

	function scheduleReveal() {
		if (revealTick) return;
		revealTick = window.requestAnimationFrame(function () {
			revealTick = 0;
			revealInViewport();
		});
	}

	revealInViewport();
	window.addEventListener('scroll', scheduleReveal, { passive: true });
	window.addEventListener('resize', scheduleReveal);
	setTimeout(function () {
		revealEls.forEach(function (el) { el.classList.add('visible'); });
	}, 2000);

	var lightbox = document.getElementById('lightbox');
	var lightboxImg = lightbox ? lightbox.querySelector('img') : null;

	function closeLightbox() {
		if (!lightbox || lightbox.hidden) return;
		lightbox.hidden = true;
		lightboxImg.removeAttribute('src');
		document.body.style.overflow = '';
	}

	if (lightbox) {
		document.querySelectorAll('img.zoomable').forEach(function (img) {
			img.addEventListener('click', function () {
				lightboxImg.src = img.currentSrc || img.src;
				lightboxImg.alt = img.alt || '';
				lightbox.hidden = false;
				document.body.style.overflow = 'hidden';
			});
		});
		lightbox.addEventListener('click', closeLightbox);
		window.addEventListener('keydown', function (event) {
			if (event.key === 'Escape') closeLightbox();
		});
	}
})();