Dark Mode Not Toggling or Persisting

1. tailwind.config.js darkMode not set to 'class' or 'media'
2. Dark class not added to html element
3. Dark mode preference not saved to localStorage
4. Page doesn't check saved preference on load
5. CSS specificity issue with dark mode selectors

Set darkMode strategy in tailwind.config.js:

export default {
  darkMode: 'class'
}

Toggle and persist:

function toggleDarkMode() {
  document.documentElement.classList.toggle('dark');
  localStorage.setItem('theme', 
    document.documentElement.classList.contains('dark') ? 'dark' : 'light'
  );
}

// On load
if (localStorage.getItem('theme') === 'dark') {
  document.documentElement.classList.add('dark');
}