Card — Article

Create card — article.

Spec: Blog post card with cover image, title, excerpt, author.

Build with:
- Tailwind 4 + shadcn/ui primitives
- Fully responsive (stacks on mobile)
- Dark mode via next-themes
- Accessible: labels, aria where needed, keyboard nav
- TypeScript props

Return a single self-contained React component. Include mock data inline so it renders standalone.