jk_na/themes/anatole/layouts/partials/footer.html

    <script>
      // This code is only used to remember theme selection between page loads
      const themeSwitch = document.querySelector('.theme-switch');
      themeSwitch.checked = localStorage.getItem('switchedTheme') === 'true';

      themeSwitch.addEventListener('change', function(e) {
        if (e.currentTarget.checked === true) {
          // Add item to localstorage
          localStorage.setItem('switchedTheme', 'true');
        } else {
          // Remove item if theme is switched back to normal
          localStorage.removeItem('switchedTheme');
        }
      });
    </script>
</body>
</html>