Preserve var() references in pasted gradient shorthand
(css-data/parse-css.ts)
When expanding shorthand properties (e.g. background), unresolved var()
tokens were lost. Now they're recovered by probing each longhand with a
placeholder, mapping which longhands the var belongs to, and restoring
it.
Fix border-(--x) Tailwind v4 syntax not recognized (tailwind.ts)
borde