How to organize routing nicely

[xperiandri]

What I have now is
""/Login
""/Layout/Main
""/Layout/SomethingElse
where "" is a shell which looks stupid a bit.
Shell which displays an extended SpashScreen is useless if I cannot put NavigationView into it so I would replace it altogether after it completed

I want to achieve
/Loading which is a full window splash screen
/Login which is a full window login page
""/Home which is a page inside my shell (layout)
""/SomethingElse which is a page inside my shell (layout)

How to achieve that?