Describe the regression

Rolldown library mode build breaks when name option contains a "." in IIFE format, works with Rollup.

Reproduction

https://github.com/ParaBolt/Rolldown-Test

• Build fails under main branch.
• A rollup branch is provided in the repo where the build works under the same setup.

Expected Behavior

Build should run successfully

Actual Behavior

After running the build with the setup described in Steps to Reproduce, the build fails with the following console error :-

error during build:
Build failed with 1 error:

[plugin vite:css-post]
RollupError: Injection point for inlined CSS not found

Steps to Reproduce

• A simple Vue component has been created with a "style" block.
• Library Mode is used to output the final build
• LibraryOptions.name contains a ".". Eg. app.namespace
• LibraryOptions.formats is set to ["iife"]
• build.cssCodeSplit is set to true
• RollupError: Injection point for inlined CSS not found

System Info

System:
    OS: Windows 11 10.0.26200
    CPU: (12) x64 AMD Ryzen 5 7530U with Radeon Graphics
    Memory: 4.01 GB / 14.83 GB
  Binaries:
    Node: 25.2.1 - C:\Program Files\nodejs\node.EXE
    Yarn: 1.22.22 - C:\Users\parab\AppData\Roaming\npm\yarn.CMD
    npm: 11.4.2 - C:\Program Files\nodejs\npm.CMD
  Browsers:
    Chrome: 144.0.7559.133
    Edge: Chromium (140.0.3485.54)
    Internet Explorer: 11.0.26100.7309
  npmPackages:
    @vitejs/plugin-vue: ^6.0.4 => 6.0.4
    vite: 8.0.0-beta.0 => 7.3.1

Used Package Manager

npm

Logs

No response

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs and the Rolldown-related guide.
• Check that there isn't already an issue that reports the same regression to avoid creating a duplicate.
• Check that this is a concrete regression. For Q&A open a GitHub Discussion or join our Discord Chat Server.
• The provided reproduction is a minimal reproducible example of the regression.

Why I Use This

I have a hybrid multi-page website where the initial file for each route is sent by the server. Vue is used to render later stuff from the client-side and there are common components used across the website which are lazy-loaded dynamically into a common namespace.