+error.svelte css import bleeds into normal layout

Describe the bug

within the +error.svelte, I have an import "error.css".

This error.css gets loaded on any normal page, regardless of the route. It seems to ALWAYS get injected.

The same even happens when i use a component within the +error.svelte and import it (i.e. i create a ErrorPage.svelte and use that within +error.svelte.

Even more annoyingly it gets loaded after the +layout.svelte's import 'main.css' .

Reproduction

https://stackblitz.com/edit/sveltejs-kit-template-default-dcy91icn?file=src%2Froutes%2F%2Bpage.svelte

Logs

System Info

System:
    OS: Linux 6.11 TUXEDO OS 24.04.1 LTS
    CPU: (16) x64 AMD Ryzen 7 8845HS w/ Radeon 780M Graphics
    Memory: 37.31 GB / 60.62 GB
    Container: Yes
    Shell: 5.2.21 - /bin/bash
  Binaries:
    Node: 22.15.0 - /usr/bin/node
    npm: 10.9.2 - /usr/bin/npm
    pnpm: 9.15.0 - /usr/bin/pnpm
  Browsers:
    Brave Browser: 135.1.77.101
  npmPackages:
    @sveltejs/adapter-node: ^5.2.12 => 5.2.12 
    @sveltejs/kit: ^2.20.7 => 2.20.7 
    @sveltejs/vite-plugin-svelte: ^5.0.3 => 5.0.3 
    svelte: ^5.27.3 => 5.27.3 
    vite: ^6.3.2 => 6.3.2

Severity

serious, but I can work around it

Additional Information

Thanks. Seriously thanks for svelte and svelteKit and all of it. cheers

Start with the linked StackBlitz reproduction, especially src/routes/+page.svelte, then inspect the referenced +error.svelte and +layout.svelte imports for error.css and main.css. Reproduce the normal-page load and compare stylesheet injection order; done means error.css is loaded only for the error route and does not override the normal layout stylesheet.