projectbased/assets/app.js

// Theme toggle (persisted)
(function(){
  const key = 'po_theme';
  const saved = localStorage.getItem(key);
  if (saved === 'light' || saved === 'dark') {
    document.documentElement.setAttribute('data-theme', saved);
  } else {
    document.documentElement.setAttribute('data-theme', 'dark');
  }
  window.POTheme = {
    toggle: function(){
      const cur = document.documentElement.getAttribute('data-theme') || 'dark';
      const next = (cur === 'dark') ? 'light' : 'dark';
      document.documentElement.setAttribute('data-theme', next);
      localStorage.setItem(key, next);
    }
  };
})();