fix(tailwind): load tailwind.config.js via @config

[camielvs]

tailwind.config.js has been dead since the v4 upgrade. Tailwind v4 is CSS-first and does not
auto-load a JS config — it only reads one when a stylesheet asks for it with @config. src/styles/global.css
never did, so the theme.extend.fontSize entries in that file were never registered and text-2xs /
text-3xs compiled to nothing.

  @import "tailwindcss";

+ @config "../../tailwind.config.js";
+
  @plugin "tailwindcss-animate";

Proof the directive takes effect

A byte-identical build is ambiguous on its own — it is also what a silently-ignored directive looks
like. So I added a probe usage (className="… text-2xs text-3xs") to a real component and built the
app both ways:

	.text-2xs	.text-3xs
with @config	font-size:.625rem ✅	font-size:.5rem ✅
without @config	not emitted	not emitted

The probe was reverted; it is not part of this diff.

Proof nothing changes today

No file under src uses text-2xs or text-3xs — zero occurrences. With the probe removed, the built
stylesheet is byte-identical to master:

master:      161,345 bytes
this branch: 161,345 bytes   (cmp: identical)

That also settles the one real risk in loading a legacy config: its content: ["./src/**/*.{js,jsx,ts,tsx}"]
key narrows source detection from v4's automatic scanning. Identical output over a full app build means
no currently-used class lives outside that glob. Worth knowing if a class is ever added to a .html,
.mdx, or .mjs file — it would need adding to content.

Why @config rather than moving the values into @theme

Chosen per request. The alternative — deleting tailwind.config.js and adding --text-2xs: 0.625rem /
--text-3xs: 0.5rem to the existing @theme inline block — would be the more idiomatic v4 shape and
would leave one place to look for theme values instead of two. Happy to switch if preferred.

Context

Found while reviewing #2624, which independently discovered the same class of bug: text-md and
font-regular in typography.tsx also emit no CSS, because --text-md and --font-weight-regular are
not defined either. That one is a separate issue — those variants are referenced by every <Text> in the
app, so defining them would change rendered output, unlike this change.

Reviewer checklist

• Agree @config is the direction, rather than folding the two steps into @theme inline
• Sanity-check that a legacy content glob is acceptable (see above)

Validation

• pnpm vite build ✅ — output byte-identical to master
• pnpm prettier --check src/styles/global.css ✅

[github-actions]

🎩 Preview

A preview build has been created at: fix/tailwind-config-directive/32b08bd

[morgan-wowk]

🤖 Agent review. Correct and byte-identical output today; one latent footgun worth weighing (inline).

[morgan-wowk]

🤖 @config correctly loads the otherwise-dead tailwind.config.js (verified: no postcss config, nothing else references it, the path resolves, and tailwind 4.3.2 supports @config). Caveat: the legacy content glob in that config pins source detection to src/**/*.{js,jsx,ts,tsx}, so any class authored outside that glob (e.g. index.html, an .mjs/.mdx) will silently fail to compile — a review-invisible visual-regression class. And it currently only feeds text-2xs/text-3xs, which have zero usages in src. The v4-idiomatic alternative — moving those two values into the existing @theme inline block as --text-2xs/--text-3xs — avoids reintroducing a content array entirely. Worth considering instead.