// Theme toggle — persisted to localStorage
(function() {
  const saved = localStorage.getItem('theme') || 'dark';
  document.documentElement.setAttribute('data-theme', saved);
})();

function initThemeToggle() {
  const btn = document.getElementById('theme-toggle');
  if (!btn) return;
  function update() {
    const t = document.documentElement.getAttribute('data-theme');
    btn.textContent = t === 'dark' ? '☀️' : '🌙';
  }
  update();
  btn.addEventListener('click', () => {
    const current = document.documentElement.getAttribute('data-theme');
    const next = current === 'dark' ? 'light' : 'dark';
    document.documentElement.setAttribute('data-theme', next);
    localStorage.setItem('theme', next);
    update();
  });
}