Thanks for your reply!
You can see both working and broken examples on this page: https://45.55.65.46/content/galleries (apologies for the IP, this is a staging site without a nice domain name yet). The dark mode toggle option is located in the footer.
I am using this plugin (with minor changes for displaying the settings toggle) for my dark mode implementation: https://www.ads-software.com/plugins/night-mode-and-font-size-kit/
