Keep components behind the scene

Hello CI,

I am using CI 3 and it is a very good tool, but with a new way of thinking of CI 4, it will be a beginning of the beautiful friendship :-)

One of the new concepts is a public folder which is disposed to the world and whole logic behind the scene and it is ultimately a good idea and solution for my business. I would like to keep the whole programming part behind the scenes and I have a simple question for this scenario.

For example bootstrap 4 (just, for example, I think on some paid software for PHP) I would like to keep original files in (for example) ThirdParty folder and subfolder power_grid, and I would like to use it in the views and what is the link to those css and js files?

Thanks for the help and support in the advance...