Instead of styling defined inside a page file, these settings are now kept in a dedicated css file. This has several advantages:
- It comes much easier to maintain styling, all css files are easy to find and update
- Browser can cache css files, which may improve page loading time
- Separate theme css files exist, no more need to make selection by coding
- This PR is a 1-to-1 move of existing inline styling to css files
- In future more optimization can be made by consolidating css files
