I've created a comprehensive mobile marketplace app called "Chợ tốt" with all the features you requested:

Key Features:

1. Mobile-First Design: Optimized for mobile devices with touch-friendly interfaces
2. Search Functionality: Keyword search with real-time filtering

3. Advanced Filters:

   • Product categories (Điện thoại, Laptop, Xe máy, etc.)
   • Price range slider
   • Brand selection
   • Product condition
   • Location/area
4. Sorting Options: Newest, cheapest, most expensive, nearest
5. Product Cards: Display images, prices, location, posting time, ratings
6. Interactive Elements: Like/favorite functionality, discount badges
7. Pi Payment Integration: Shows 0.1π transaction fee at the bottom

Mobile Optimizations:

• Responsive Grid: 2-column product grid for mobile
• Touch-Friendly: Large tap targets and smooth interactions
• Sticky Header: Search bar stays accessible while scrolling
• Side Sheet Filters: Mobile-optimized filter panel
• Vietnamese Language: All text in Vietnamese as requested
• Compact Layout: Efficient use of screen space

The app includes sample Vietnamese marketplace data with realistic products, prices in VND, and Vietnamese locations (Ho Chi Minh City districts). The design uses a clean, modern interface with orange accent colors typical of Vietnamese e-commerce platforms.