Dark theme css

Hello,
Great plugin. I’ve installed it and created one course and now I’m creating another. My website layout is dark, and the first course information page has a white background, which is fine, but the second course (created in the same way) has a black background and it doesn’t look good at all. My question is – do you have an option for dark theme or maybe some help with deciding why the one course looks different than another.
Dark: https://www.coaching-blackbelt.com/courses/yellow-belt-package-8th-7th-kup/
White: https://www.coaching-blackbelt.com/courses/white-belt-package/
Thank you in advance!

The page I need help with: [log in to see the link]