script.js

(function(){
  
  if (window.matchMedia && window.matchMedia('(prefers-reduced-motion: reduce)').matches) {

    document.querySelectorAll('.reveal').forEach(el => el.classList.add('active'));
    return;
  }

  const reveals = document.querySelectorAll('.reveal');

  const observerOptions = {
    root: null,
    rootMargin: '0px 0px -10% 0px', 
    threshold: 0.15 
  };

  const observer = new IntersectionObserver((entries, obs) => {
    entries.forEach(entry => {
      if (entry.isIntersecting) {
        const el = entry.target;


        const delayAttr = el.getAttribute('data-delay');
        if (delayAttr) {
          el.style.transitionDelay = `${delayAttr}ms`;
        } else {
         
        }

        
        el.classList.add('active');


        obs.unobserve(el);

       
      }
    });
  }, observerOptions);

  reveals.forEach(el => observer.observe(el));

  if (!('IntersectionObserver' in window)) {
    window.addEventListener('scroll', fallbackThrottle);
    window.addEventListener('resize', fallbackThrottle);

    fallbackThrottle();

    function fallbackThrottle() {

      if (window._revealTimeout) clearTimeout(window._revealTimeout);
      window._revealTimeout = setTimeout(checkFallback, 100);
    }

    function checkFallback() {
      const viewportTop = window.scrollY;
      const viewportBottom = viewportTop + window.innerHeight;
      document.querySelectorAll('.reveal').forEach(el => {
        const rect = el.getBoundingClientRect();
        const elTop = rect.top + window.scrollY;
        const elBottom = elTop + rect.height;
        // se 15% do elemento estiver visível
        const visible = (elBottom - (rect.height * 0.85)) <= viewportBottom && (elTop + (rect.height * 0.15)) >= viewportTop;
        if (visible) {
          el.classList.add('active');
        }
      });
    }
  }
})();

document.querySelectorAll('a[href^="#"]').forEach(link => {
  link.addEventListener('click', function(e) {
    e.preventDefault();
    document.querySelector(this.getAttribute('href'))
      .scrollIntoView({ behavior: 'smooth' });
  });
});