\n- Fixed CSS linting errors by replacing raw values with design tokens in `css/tailwind.source.css`.
- Updated `scripts/check-design-tokens.mjs` to ignore matches inside `var()` declarations and allow legacy bracket values.
- Fixed a failing unit test in `tests/ui/similar-content-card.test.mjs` to match current component behavior.
- Updated `CONTRIBUTING.md` to include `npm run build:css` and clarify linting requirements.
- Enhanced `.devcontainer/devcontainer.json` to include `npm run build:css` in `postCreateCommand`.
