// Hamburger menu
    const hamburger = document.getElementById('hamburger');
    const sidebar = document.getElementById('sidebar');
    const overlay = document.getElementById('sidebar-overlay');

    hamburger.addEventListener('click', () => {
      sidebar.classList.toggle('open');
      overlay.classList.toggle('open');
    });

    overlay.addEventListener('click', () => {
      sidebar.classList.remove('open');
      overlay.classList.remove('open');
    });

    // Close sidebar on nav click (mobile)
    sidebar.querySelectorAll('a').forEach(link => {
      link.addEventListener('click', () => {
        if (window.innerWidth <= 900) {
          sidebar.classList.remove('open');
          overlay.classList.remove('open');
        }
      });
    });

    // Highlight active section on scroll
    const sections = document.querySelectorAll('.seccion-titulo');
    const navLinks = document.querySelectorAll('.sidebar-nav a[data-section]');

    const observer = new IntersectionObserver((entries) => {
      entries.forEach(entry => {
        if (entry.isIntersecting) {
          navLinks.forEach(link => link.classList.remove('active'));
          const id = entry.target.id;
          const activeLink = document.querySelector('.sidebar-nav a[data-section="' + id + '"]');
          if (activeLink) {
            activeLink.classList.add('active');
            activeLink.scrollIntoView({ block: 'nearest', behavior: 'smooth' });
          }
        }
      });
    }, { rootMargin: '-10% 0px -80% 0px' });

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