index.js

function smoothScrollTo(target, duration = 1200) {
  const start = window.pageYOffset;
  const end = target.getBoundingClientRect().top + start - 80; // -80px pour compenser la navbar
  const distance = end - start;
  let startTime = null;

  function animation(currentTime) {
    if (!startTime) startTime = currentTime;
    const timeElapsed = currentTime - startTime;
    const progress = Math.min(timeElapsed / duration, 1);
    // Easing (accélère puis ralentit)
    const ease = progress < 0.5
      ? 4 * progress * progress * progress
      : 1 - Math.pow(-2 * progress + 2, 3) / 2;
    window.scrollTo(0, start + distance * ease);

    if (timeElapsed < duration) requestAnimationFrame(animation);
  }

  requestAnimationFrame(animation);
}


// Dark/Light toggle
const toggle = document.getElementById("theme-toggle");

toggle.addEventListener("click", () => {
  const currentTheme = document.documentElement.getAttribute("data-theme");
  const newTheme = currentTheme === "light" ? "dark" : "light";
  document.documentElement.setAttribute("data-theme", newTheme);
  toggle.textContent = newTheme === "light" ? "🌞" : "🌙";
});

// Scroll animation
const sections = document.querySelectorAll('.section');

// Smooth scroll pour les liens du navbar
document.querySelectorAll('.navbar a[href^="#"]').forEach(anchor => {
  anchor.addEventListener('click', function(e) {
    e.preventDefault();
    const target = document.querySelector(this.getAttribute('href'));
    smoothScrollTo(target, 1500); // défilement en 1,5s
  });
});


const observer = new IntersectionObserver(entries => {
  entries.forEach(entry => {
    if (entry.isIntersecting) {
      entry.target.classList.add('visible');

      // Stagger des enfants
      const items = entry.target.querySelectorAll('.animate-item');
      items.forEach((item, i) => {
        item.style.transitionDelay = `${i * 0.2}s`; // 0.2s entre chaque
      });
    }
  });
}, { threshold: 0.1 });


sections.forEach(section => {
  observer.observe(section);
});