document.addEventListener("DOMContentLoaded", function() {
    // Menu Toggle
    const toggleBtn = document.getElementById("mobile-menu-toggle");
    const navMenu   = document.getElementById("site-navigation");
    if (toggleBtn && navMenu) {
        toggleBtn.addEventListener("click", function() {
            toggleBtn.classList.toggle("active");
            navMenu.classList.toggle("active");
        });
    }

    // Back to Top
    const bttBtn = document.getElementById("back-to-top");
    if (bttBtn) {
        window.addEventListener("scroll", function() {
            if (window.scrollY > 350) { bttBtn.classList.add("show"); } else { bttBtn.classList.remove("show"); }
        });
        bttBtn.addEventListener("click", function() {
            window.scrollTo({ top: 0, behavior: "smooth" });
        });
    }

    // Accessibility Panel
    const a11yTrigger = document.getElementById("a11y-trigger");
    const a11yPanel   = document.getElementById("a11y-panel");
    const a11yClose   = document.getElementById("a11y-close");
    if (a11yTrigger && a11yPanel) {
        a11yTrigger.addEventListener("click", function() { a11yPanel.classList.toggle("active"); });
        if (a11yClose) { a11yClose.addEventListener("click", function() { a11yPanel.classList.remove("active"); }); }

        const fontLevels = ['', 'a11y-font-lg', 'a11y-font-xl'];
        let currentFontIdx = parseInt(localStorage.getItem('edukarsa_a11y_font') || '0', 10);
        function applyA11y() {
            fontLevels.forEach(function(c) { if (c) document.body.classList.remove(c); });
            if (fontLevels[currentFontIdx]) { document.body.classList.add(fontLevels[currentFontIdx]); }
            if (localStorage.getItem('edukarsa_a11y_contrast') === '1') { document.body.classList.add('a11y-high-contrast'); } else { document.body.classList.remove('a11y-high-contrast'); }
            if (localStorage.getItem('edukarsa_a11y_grayscale') === '1') { document.body.classList.add('a11y-grayscale'); } else { document.body.classList.remove('a11y-grayscale'); }
            if (localStorage.getItem('edukarsa_a11y_links') === '1') { document.body.classList.add('a11y-underline-links'); } else { document.body.classList.remove('a11y-underline-links'); }
        }
        applyA11y();

        document.getElementById("a11y-font-inc")?.addEventListener("click", function() { if (currentFontIdx < fontLevels.length - 1) currentFontIdx++; localStorage.setItem('edukarsa_a11y_font', currentFontIdx); applyA11y(); });
        document.getElementById("a11y-font-dec")?.addEventListener("click", function() { if (currentFontIdx > 0) currentFontIdx--; localStorage.setItem('edukarsa_a11y_font', currentFontIdx); applyA11y(); });
        document.getElementById("a11y-font-reset")?.addEventListener("click", function() { currentFontIdx = 0; localStorage.setItem('edukarsa_a11y_font', currentFontIdx); applyA11y(); });
        document.getElementById("a11y-contrast")?.addEventListener("click", function() { const active = localStorage.getItem('edukarsa_a11y_contrast') === '1'; localStorage.setItem('edukarsa_a11y_contrast', active ? '0' : '1'); applyA11y(); });
        document.getElementById("a11y-grayscale")?.addEventListener("click", function() { const active = localStorage.getItem('edukarsa_a11y_grayscale') === '1'; localStorage.setItem('edukarsa_a11y_grayscale', active ? '0' : '1'); applyA11y(); });
        document.getElementById("a11y-links")?.addEventListener("click", function() { const active = localStorage.getItem('edukarsa_a11y_links') === '1'; localStorage.setItem('edukarsa_a11y_links', active ? '0' : '1'); applyA11y(); });
        document.getElementById("a11y-reset-all")?.addEventListener("click", function() {
            currentFontIdx = 0;
            localStorage.removeItem('edukarsa_a11y_font');
            localStorage.removeItem('edukarsa_a11y_contrast');
            localStorage.removeItem('edukarsa_a11y_grayscale');
            localStorage.removeItem('edukarsa_a11y_links');
            applyA11y();
        });
    }

    // Homepage Hero Slider Scroll
    const slider = document.getElementById('hero-slider-wrapper');
    if (slider && slider.children.length > 1) {
        setInterval(function() {
            if (slider.scrollLeft + slider.clientWidth >= slider.scrollWidth - 10) {
                slider.scrollTo({ left: 0, behavior: 'smooth' });
            } else {
                slider.scrollBy({ left: slider.clientWidth, behavior: 'smooth' });
            }
        }, 4000);
    }
});