v4 intellisense suggests underscore instead of dot in custom utilities

[unional]

What version of VS Code are you using?

v1.98.2

What version of Tailwind CSS IntelliSense are you using?

v0.14.15

What version of Tailwind CSS are you using?

v4.1.0

What package manager are you using?

pnpm

What operating system are you using?

macOS

Tailwind config

@theme static {
  --container-height-3_5: calc(theme(--spacing) * 3.5);
)

@utility container-h-* {
  height: --value(--container-height- *);
}

Reproduction URL

TBD

Describe your issue

On the CSS side, the variable needs avoid .,
thus the CSS variable is --container-height-3_5 instead of --container-height-3.5.

The @utility container-h-* {} generates/detect container-h-3.5 instead of container-h-3_5.

However the intellisense suggests container-h-3_5 which does not work.

My guess this is a regression caused by: #1184

[thecrypticace]

This looks to be a bug in @utility-driven suggestions specifically. We got those added recently and probably missed this edge case. The _ should be replaced with a dot when surrounded by digits. Though at this point we consider that a legacy behavior. You can write the variable itself with a dot by escaping it:

@theme static {
  --container-height-3\.5: calc(theme(--spacing) * 3.5);
}

@utility container-h-* {
  height: --value(--container-height- *);
}

[thecrypticace]

Found the bug and opened a PR in Tailwind CSS itself to fix it 👍 (will close this issue once it's merged)

[thecrypticace]

This will be fixed in the next version of Tailwind CSS.

I would suggest writing your theme keys with an escaped dot however as there's maybe a small chance we'll remove this behavior in a future release (as it was intended only for backwards compatibility with alpha/beta releases to help people migrate)