Starting Style in the Base Layer

[audinue]

What version of Tailwind CSS are you using?

4.1.8

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

Vite, Playground

What version of Node.js are you using?

23.11.1

What browser are you using?

Edge 137.0.3296.68
Chrome 137.0.7151.104

What operating system are you using?

Windows 10

Reproduction URL

https://play.tailwindcss.com/d5N8skje1t

Describe your issue

starting:opacity-0 doesn't work when it's generated in the base layer.

I've provided 4 examples to demonstrated that:

1. starting:opacity-0 (generated in base layer)
2. [@starting-style]:opacity-0 (generated in base layer)
3. starting-opacity-bug (generated in base layer)
4. starting-opacity-0-fix (not in base layer → works)

video_2025_06_11_08_23.webm