React News Website with Sanity

I need a modern, mobile-responsive news portal built with React.js on the front end and Sanity CMS powering all content. The site will carry standard news categories—Sports, Business, Technology, Education, Entertainment and any others I can add later—and it should be simple for me to publish, edit or delete stories inside Sanity without touching code.

Core features
• Featured and latest news blocks surfaced on the homepage, with clean routing to full-width article pages.
• Category pages that automatically list the newest stories first.
• Social share buttons for Facebook, Twitter, Instagram and a one-tap WhatsApp share on each article.
• A professional UI that scales gracefully across smartphones, tablets and desktops, built with semantic HTML5 and lightweight CSS modules (no WordPress, no bulky themes).

From the CMS side I expect:
• A flexible schema so I can add new categories or change field names later.
• Rich-text editing, image upload with alt-text, and slug control.
• Role-based access if I decide to add other editors in the future.

Acceptance criteria
1. Codebase delivered as a Git repository with clear README for local setup.
2. Sanity studio configured and deployed, ready for me to log in and start posting.
3. Lighthouse mobile performance score of 90+ on the main pages.
4. All requested sharing links fully functional.

Please share a link to at least one React-based project you’ve shipped, a brief outline of your approach to structuring Sanity schemas, and your estimated timeline with cost.