tailwindcss css output don't being putted inside ./package/

Describe the bug

basically, I was creating a simple library with sveltekit and using tailwindcss. the problem is when I do "npm run build" it creates the files correctly but when i do npm install of the same file. the component don't have any CSS applied to it.

Reproduction

my npm package: https://www.npmjs.com/package/mathview-svelte
my GitHub repo: https://github.com/Laaouatni/MathViewSvelte

example of the error: https://svelte.dev/repl/39421699a03f4717a74e6665f7055eff?version=3.55.1

what should output:

what is wrong:

another info is that tailwind works fine in dev mode "npm run dev", but when build don't work fine.

how make also the css being exported with the component library?

System Info

System:
    OS: Windows 10 10.0.22621
    CPU: (8) x64 11th Gen Intel(R) Core(TM) i5-1135G7 @ 2.40GHz
    Memory: 1.04 GB / 7.65 GB
  Binaries:
    Node: 16.14.0 - C:\Program Files\nodejs\node.EXE
    npm: 9.3.1 - C:\Program Files\nodejs\npm.CMD    
  Browsers:
    Edge: Spartan (44.22621.1105.0), Chromium (109.0.1518.55)
    Internet Explorer: 11.0.22621.1
  npmPackages:
    @sveltejs/adapter-auto: ^1.0.0 => 1.0.2
    @sveltejs/kit: ^1.0.0 => 1.2.6
    @sveltejs/package: ^1.0.0 => 1.0.2
    svelte: ^3.54.0 => 3.55.1
    vite: ^4.0.0 => 4.0.4

Severity

annoyance

Additional Information

No response

Start with the linked MathViewSvelte reproduction and compare the files produced by npm run build with the installed package output. Check how the SvelteKit package build handles Tailwind CSS assets, then verify the fix by installing the built package and confirming the component's CSS is applied.