Restore text-5xl through text-9xl in @theme (currently reset to initial)

[MaxGhenis]

Issue

@policyengine/ui-kit/theme.css resets --text-*: initial and only redefines text-xs through text-4xl. Every consumer that uses text-5xl, text-6xl, text-7xl, text-8xl, or text-9xl (notably all slide-deck repos) gets a build error:

Cannot apply unknown utility class 'text-6xl'

Why this is real

Found while migrating 9 PolicyEngine slide-deck repos from Next 14 + Tailwind 3 to Next 16 + Tailwind 4 + ui-kit ^0.9.0. Every one of them uses text-5xl-text-9xl for slide titles. Each migration had to add a local @theme override block in app/globals.css:

@theme {
  --text-5xl: 3rem;
  --text-5xl--line-height: 1;
  --text-6xl: 3.75rem;
  --text-6xl--line-height: 1;
  --text-7xl: 4.5rem;
  --text-7xl--line-height: 1;
  --text-8xl: 6rem;
  --text-8xl--line-height: 1;
  --text-9xl: 8rem;
  --text-9xl--line-height: 1;
}

That's nine duplicated copies of the same Tailwind defaults across the org, which defeats the purpose of a centralized design system.

Suggested fix

Ship text-5xl through text-9xl in src/theme/tokens.css @theme block. The default Tailwind v4 values (matching v3 behavior) are listed above. If the design intent was to intentionally drop them, the JSDoc on --text-*: initial in theme.css should say so explicitly.

Affected consumers

All 9 slide-deck repos that just got migrated:

• mn-house-research-demo-2025
• nuffield-2026-01-09-slides
• policyengine-demo
• ri-ctc-calculator-webinar
• slides-2026-01-16-arnold
• talk-georgetown-ppol6362-2026-01-12
• taxsim-emulator-demo-day-slides
• team-meeting-2026-slides
• vanderbilt-state-tax-policy-academy-2025

Once ui-kit ships these tokens, the local @theme overrides can be deleted from each.

[policyengine]

✅ Fixed in PR #33

Added text-5xl through text-9xl to src/theme/tokens.css using the standard Tailwind v4 defaults:

• text-5xl: 3rem / line-height: 1
• text-6xl: 3.75rem / line-height: 1
• text-7xl: 4.5rem / line-height: 1
• text-8xl: 6rem / line-height: 1
• text-9xl: 8rem / line-height: 1

These match the values you had to duplicate across the 9 slide-deck repos. Once merged, you can remove those local @theme overrides.

The fix follows the existing pattern in the file (same format as text-xs through text-4xl) and uses the exact values from the Tailwind defaults.