[v4] Custom keyframes are not generated if the value of an animation variable contains a line break between the keyframe name and duration

[ony3000]

What version of Tailwind CSS are you using?

v4.0.3

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

Vite 6.0.5

What version of Node.js are you using?

v18.18.2

What browser are you using?

Chrome

What operating system are you using?

WSL

Reproduction URL

https://play.tailwindcss.com/PyXgGbc7uU?file=css

Describe your issue

If the keyframe name and duration are on different lines, the custom keyframe is not generated.

--animate-foo: <keyframe-name>
  <duration> <easing-function> <delay> <iteration-count> <direction> <fill-mode> <play-state>

If the keyframe name and duration are on the same line, the custom keyframe is generated.

--animate-foo: <keyframe-name> <duration>
  <easing-function> <delay> <iteration-count> <direction> <fill-mode> <play-state>

[RobinMalfait]

Hey!

Thanks for the bug report, this is fixed by #16237 and will be available in the next release.