I've created a complete travel challenge interface based on the reference image, with the following key features:

1. Fixed width of 750px as requested
2. Primary blue color (#1e4ff2) and secondary orange color (#ffb400) as specified
3. Responsive layout with proper spacing and hierarchy

4. All major sections from the reference image:

   • Header with navigation and share buttons
   • Timer and main CTA
   • Global Traveller Award section with icons
   • Challenge statistics
   • Hashtag challenges with progress bars
   • Timeline section
   • Daily tasks with rewards

The interface uses shadcn/ui components for consistent styling and interactions, and Tailwind CSS for layout and responsive design. The design maintains the mobile-first approach while being optimized for the specified 750px width.

Would you like me to make any adjustments to the design or functionality?