(() => {
  const header = document.querySelector('[data-header]');
  const toggle = document.querySelector('[data-nav-toggle]');
  const nav = document.querySelector('[data-nav]');
  const backdrop = document.querySelector('[data-nav-backdrop]');

  const onScroll = () => header?.classList.toggle('is-scrolled', window.scrollY > 18);
  onScroll();
  window.addEventListener('scroll', onScroll, { passive: true });

  const setNav = (open) => {
    if (!toggle || !nav) return;
    nav.classList.toggle('is-open', open);
    toggle.classList.toggle('is-open', open);
    toggle.setAttribute('aria-expanded', String(open));
    toggle.setAttribute('aria-label', open ? 'Close menu' : 'Open menu');
    document.body.classList.toggle('no-scroll', open);
    document.body.classList.toggle('nav-open', open);
    if (backdrop) backdrop.tabIndex = open ? 0 : -1;
  };

  if (toggle && nav) {
    toggle.addEventListener('click', () => setNav(!nav.classList.contains('is-open')));
    backdrop?.addEventListener('click', () => setNav(false));
    nav.querySelectorAll('a').forEach(link => link.addEventListener('click', () => setNav(false)));
    document.addEventListener('keydown', (event) => {
      if (event.key === 'Escape') setNav(false);
    });
    window.addEventListener('resize', () => {
      if (window.innerWidth > 860) setNav(false);
    });
  }

  const revealTargets = document.querySelectorAll('.destination-card,.home-destination-card,.tour-card,.experience-card,.impact-project,.metric-grid article,.home-story-points a');
  if ('IntersectionObserver' in window) {
    const observer = new IntersectionObserver(entries => {
      entries.forEach(entry => {
        if (entry.isIntersecting) {
          entry.target.animate([
            { opacity: 0, transform: 'translateY(18px)' },
            { opacity: 1, transform: 'translateY(0)' }
          ], { duration: 520, easing: 'cubic-bezier(.2,.7,.2,1)', fill: 'both' });
          observer.unobserve(entry.target);
        }
      });
    }, { threshold: .08 });
    revealTargets.forEach(el => observer.observe(el));
  }
})();