Improve the look of the new sale page with more visually appealing colors

Harmonizes background colors in New Sale form (index.css) and updates replit.md to reflect the UI changes.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: dec54137-d5a2-4406-8ad4-5f2f9fb110bf
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/0715008c-7244-40f4-befc-26c014852236/a57458a0-f014-4f78-9cf2-914103a1fadf.jpg

replit.md

@@ -240,6 +240,9 @@ Preferred communication style: Simple, everyday language.
 - ✅ Optimized border thickness for better balance between visibility and aesthetics
 - ✅ Removed manual date field from new sale form - timestamp now automatically recorded
 - ✅ Automatic date/time creation ensures accuracy and prevents manual entry errors
+- ✅ Added date and time display in sales history with automatic timestamp from database
+- ✅ Harmonized color scheme in new sale form with softer, complementary colors
+- ✅ Updated section backgrounds to work cohesively with green save button
 
 ### Docker Configuration & Cleanup (January 9, 2025)
 - ✅ Complete Docker setup optimized for external PostgreSQL database