imports css with @layer base { }

[g1oomycat]

What version of Tailwind CSS are you using?

For example: v4.0.6

What build tool (or framework if it abstracts the build tool) are you using?

For example: Next.js 15.1.7

What version of Node.js are you using?

For example: v20.0.0

What browser are you using?

For example: Chrome

What operating system are you using?

For example: Windows

Describe your issue

I'm using the Feature-Sliced Design (FSD) architecture and prefer to keep styles in separate files. However, I've encountered a problem with Tailwind CSS:

If I import a CSS file into globals.css that contains @layer base {}, Tailwind stops working entirely.

Even if I also add @layer base {} directly inside globals.css, it doesn't override anything — instead, it just breaks the whole app.

[wongjn]

Consider providing a git repo that reproduces the issue and we can take a look for you.