I'm very confused about styling and naming conventions

Basically every library has their own coding style.

Everyone uses different extensions for some reason, see `.h`, `.hpp`, `.hh` for header files, `.cc` `.cpp` `.C` for sources , `.cppm` and `.ixx` for module interfaces etc.

Everyone uses different naming conventions, STL uses snake_case with _type suffix for classes sometimes _t and sometimes nothing. Google uses CamelCase etc.

It seems to me no majority consensus has emerged, and it really hurts even thinking about these things before you write your own code. As each dependency you use has a different coding style.

How do people even solve it? Is there a hidden style guide that everyone uses that I don't know. core guidelines isn't really a style guide in the purest sense.