Vite moves @import at the top leading to an erroneous layers order

[ellhn]

Describe the bug

I am applying the following css:

@layer reset, bootstrap;
@import url('https://cdn.jsdelivr.net/npm/bootstrap@5.3.0/dist/css/bootstrap.css') layer(bootstrap);

@layer reset {
  h1 {
    margin-top: 100px;
  }
}

to <h1>Text</h1>

I am expecting:
bootstrap layer to take precedence over reset layer and h1 to have a top margin of 0px.

What is actually happening:
reset layer takes precedence over bootstrap layer and h1 has a top margin of 100px.

Reproduction

https://stackblitz.com/edit/vitejs-vite-ucaxjr?file=main.js,style.css&terminal=dev

Steps to reproduce

No response

System Info

Chrome and Firefox

Used Package Manager

npm

Logs

No response

Validations

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• The provided reproduction is a minimal reproducible example of the bug.

[stackblitz]

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• vitejs-vite-ucaxjr (Open reproduction)

[sapphi-red]

This seems to be an upstream issue: postcss/postcss-import#567