Summary

• Updates the Tailwind CSS toolchain in the two example apps to the latest stable Tailwind CSS 4.3.0 release.
• Migrates from v3 JavaScript config files and @tailwind directives to Tailwind v4 CSS-first setup.
• Uses the Angular CLI app's documented @tailwindcss/postcss integration and switches the Analog/Vite app to @tailwindcss/vite.
• Converts the Angular example global stylesheet from SCSS to CSS, preserving component-scoped @apply usage with Tailwind v4 @reference where theme utilities are applied.
• Preserves v3 default border-color behavior with the compatibility base layer recommended by the v4 upgrade flow.

Validation

• pnpm install --frozen-lockfile
• pnpm build
• pnpm lint
• CSS smoke checks confirmed both example app bundles contain generated Tailwind utilities/typography output and no raw Tailwind directives in emitted CSS.
• Verified the Sanity example component styles compile @apply/@reference into concrete scoped CSS with no raw directives in the built output.

Notes

• pnpm peers check still exits non-zero. This repo already has several peer-version drifts; this update also adds the expected Tailwind 4 warning against Angular 19 packages that declare tailwindcss ^2 || ^3 as an optional peer. The actual Angular build path is verified via the documented @tailwindcss/postcss integration.
• Latest versions were checked from npm metadata: tailwindcss@4.3.0, @tailwindcss/postcss@4.3.0, @tailwindcss/vite@4.3.0, and @tailwindcss/typography@0.5.19.

References: https://tailwindcss.com/docs/upgrade-guide, https://tailwindcss.com/docs/installation/framework-guides/angular, https://tailwindcss.com/docs/installation/using-vite, https://tailwindcss.com/docs/detecting-classes-in-source-files