Style switcher in panel

The CMS Questions
3

Ah, I figured it out, both with a checkbox and with a toggler.

Just if anybody else wants to do it:

In the blueprint add the following lines:

background:
  label: Background
  type: checkbox
  text: Dark Background?

Then in the <head> section:

<?php if($page->background() == '1'): ?>
  <?php echo css('/assets/css/dark.css') ?>
<?php endif ?>