I have a working application that use Nextjs page router. I got a task to create new landing page, and decided to use app router. But when I create hello world page and build it, the bundle size is big, half of the initial js size of my page router.

the initial js size is around 190kb, whereas my pure app router with many feature started only at 87kb.

why is this happened? does packages or code from page router also bundled in app router generated code?
also, im using tailwindcss, can I just generate css sepearetely for the app router? Thanks

What i expect is smaller bundle size in app router