Enhance PHP E-Commerce Checkout

Job ID: 40302756

Budget: $30 – $250 USD

I have completed the upgrade for your PHP store, ensuring full compliance with all your requirements.

Technical implementation details:

PhonePe Integration: I fixed the duplicate ID issues by implementing a unique merchantTransactionId logic (combining Order ID + Timestamp + Random seed).

Real-time Cart: Used Vanilla JS (XMLHttpRequest) to ensure totals auto-update instantly without page refreshes, maintaining a lightweight and fast store.

Product Colors: Added full support for color selection, which is now correctly passed and saved in the order record.

Database & Code: Switched to PDO in db.php for better security and followed a "Clean Code" approach. All comments are in English for your review.

Mobile Optimization: The quantity selector and checkout flow are 100% mobile-friendly.

The attached ZIP includes:

All 9 updated PHP/JS files.

migration.sql to update your database tables.

A README.txt with simple installation steps.