phsl / new-api

- Remove example image and right-side image section for cleaner layout
- Center all content vertically and horizontally on the page
- Implement comprehensive responsive design using Tailwind CSS breakpoints
  - Typography scales from text-3xl to xl:text-6xl across screen sizes
  - Spacing and padding adjust dynamically (py-12 to lg:py-20)
  - Icon grid adapts from gap-3 to lg:gap-8
- Keep action buttons horizontally aligned on all screen sizes
- Add play icon to "Get Started" button for better UX
- Refactor version display logic:
  - Show version tag only in demo site mode
  - Replace GitHub button text with version number in demo mode
  - Add docs button with same logic as HeaderBar when not in demo mode
- Optimize icon layout with consistent 40px size and responsive containers
- Improve overall mobile-first responsive design from 320px to 1280px+ screens