What version of Tailwind CSS are you using?

For example: v3.4.1

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

Tailwind Play

What version of Node.js are you using?

Tailwind Play

What browser are you using?

Safari

What operating system are you using?

macOS

Reproduction URL

https://play.tailwindcss.com/ZnkOJe6wYV

Describe your issue

In the reproduction, notice that because of the important: ':root' option, [animation-duration:5s] doesn't override the duration from animate-spin. That is because its generated CSS is:

.\[animation-duration\:5s\]{
  animation-duration: 5s
}

instead of the expected:

:root :is(.\[animation-duration\:5s\]){
  animation-duration: 5s
}