(() => {
  const header = document.querySelector(".site-header");
  const onScroll = () => {
    if (!header) return;
    header.classList.toggle("is-scrolled", window.scrollY > 12);
  };
  onScroll();
  window.addEventListener("scroll", onScroll, { passive: true });

  const reveals = document.querySelectorAll(".reveal");
  if ("IntersectionObserver" in window) {
    const observer = new IntersectionObserver(
      (entries) => {
        entries.forEach((entry, index) => {
          if (!entry.isIntersecting) return;
          const el = entry.target;
          el.style.transitionDelay = `${Math.min(index * 0.04, 0.2)}s`;
          el.classList.add("is-visible");
          observer.unobserve(el);
        });
      },
      { threshold: 0.12, rootMargin: "0px 0px -8% 0px" }
    );
    reveals.forEach((el) => observer.observe(el));
  } else {
    reveals.forEach((el) => el.classList.add("is-visible"));
  }
})();