document.addEventListener('DOMContentLoaded', () => {
  // ── Loading overlay ────────────────────────────────────
  const overlay = document.getElementById('loading-overlay');

  document.querySelectorAll('form').forEach((form) => {
    form.addEventListener('submit', () => {
      if (overlay) overlay.classList.add('active');
    });
  });

  // ── Hamburger menu ─────────────────────────────────────
  const hamburger = document.querySelector('.hamburger');
  const navLinks = document.querySelector('.nav-links');

  if (hamburger && navLinks) {
    hamburger.addEventListener('click', () => {
      navLinks.classList.toggle('open');
    });
  }

  // ── Generate dropdown tabs ─────────────────────────────
  document.querySelectorAll('.tab-btn').forEach((btn) => {
    btn.addEventListener('click', () => {
      const target = btn.dataset.tab;
      const container = btn.closest('.tabs-container');
      if (!container) return;

      container.querySelectorAll('.tab-btn').forEach((b) => b.classList.remove('active'));
      container.querySelectorAll('.tab-panel').forEach((p) => p.classList.remove('active'));

      btn.classList.add('active');
      const panel = container.querySelector(`#tab-${target}`);
      if (panel) panel.classList.add('active');
    });
  });
});