document.addEventListener('DOMContentLoaded', () => {

    // --- 1. Navbar Scroll Effect ---
    const navbar = document.querySelector('.navbar');
    window.addEventListener('scroll', () => {
        if (window.scrollY > 50) {
            navbar.classList.add('scrolled');
        } else {
            navbar.classList.remove('scrolled');
        }
    });

    // --- 2. Powerful Scroll Effects (Reveal Animations) ---
    const revealElements = document.querySelectorAll('.reveal-up, .reveal-left, .reveal-right, .zoom-in');
    
    const revealOptions = {
        threshold: 0.15,
        rootMargin: "0px 0px -50px 0px"
    };

    const revealObserver = new IntersectionObserver((entries, observer) => {
        entries.forEach(entry => {
            if (!entry.isIntersecting) return;
            entry.target.classList.add('active');
            observer.unobserve(entry.target);
        });
    }, revealOptions);

    revealElements.forEach(el => {
        revealObserver.observe(el);
    });

    // --- 3. Stagger Delays for Grids (Experience Cards) ---
    const staggerItems = document.querySelectorAll('.stagger-item');
    staggerItems.forEach((item, index) => {
        item.style.transitionDelay = `${index * 0.15}s`;
    });

    // --- 4. Animated Numbers (Counter Animation) ---
    const counters = document.querySelectorAll('.counter');
    const counterOptions = {
        threshold: 0.5
    };

    const counterObserver = new IntersectionObserver((entries, observer) => {
        entries.forEach(entry => {
            if (!entry.isIntersecting) return;
            
            const counter = entry.target;
            counter.innerText = '0';
            
            const target = +counter.getAttribute('data-target');
            const duration = 2000; // 2 seconds animation
            const increment = target / (duration / 16); // 60 FPS
            
            const updateCounter = () => {
                const current = +counter.innerText;
                if (current < target) {
                    counter.innerText = Math.ceil(current + increment);
                    setTimeout(updateCounter, 16);
                } else {
                    counter.innerText = target;
                }
            };
            
            updateCounter();
            observer.unobserve(counter);
        });
    }, counterOptions);

    counters.forEach(counter => {
        counterObserver.observe(counter);
    });

});