No need for any third-party stuff to try customizing Discourse without hassle.
You can do it here https://theme-creator.discourse.org/. That’s what it’s made for.
you can create themes from your profile menu: https://theme-creator.discourse.org/my/themes
All the forum components appearances are referenced here: https://theme-creator.discourse.org/styleguide/
And for the post style itself: https://theme-creator.discourse.org/styleguide/organisms/post
CSS modifications from your newly created themes are applied in real-time, no need to reload the pages.
More info:
Can you elaborate? Do you ask us to be creative and suggest other ideas, or write CSS for you?