[v4] Is there a way to keep underscores in theme variables?

[Gomah]

What version of Tailwind CSS are you using?

v4.0.0-alpha.9

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

React 18.2.0, Vite 5.1.6

What version of Node.js are you using?

Bun 1.0.30

What browser are you using?

Chrome

What operating system are you using?

macOS

Reproduction URL

Tailwind play: https://play.tailwindcss.com/iSxc1ooIhz – But it doesn't support v4 yet,

@tailwind base;

@theme {
  --text-color-primary: var(--text-primary);
  --text-primary_on-brand: var(--text-primary_on-brand);
}

:root {
  --text-primary: var(--color-gray-900);
  --text-primary_on-brand: var(--color-base-white);
}

.dark {
  --text-primary: var(--color-gray-50);
  --text-primary_on-brand: var(--color-gray-50);
}

Describe your issue

Theme variables containing underscores are translated to dots, e.g:

It makes sense though as I use underscore to translate into dots, e.g : ring-width-1_5, but is there a way to keep the underscore intact somehow? I tried with \_ but no luck.

[Gomah]

This PR fixes it ✌🏻