Improve the appearance of the website's main section on all devices

Refactor CSS styles to optimize typography and layout of the hero section in style.css, and update index.html and script.js.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: d268d0e7-95bc-4700-aeac-ada7c54fb6da
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/39743672-205e-47e2-9c35-def45b127242/d78b1add-f68d-4d7d-bf3a-31934f797fca.jpg
