zengjie simple-invoice-generator .cursorrules file for JavaScript

## Code Style and Structure
- Write concise, readable, and maintainable Python code.
- Use FastAPI and FastHX for the API and frontend.
- Use Jinja for the HTML templates.
- Use ReportLab for the PDF generation.

## Naming Conventions
- Use lowercase with underscores for variable and function names.
- Use CamelCase for class names.
- Use UPPERCASE for constants.

## File Structure
- Use templates/ for the HTML templates.
- Use static/ for the static files.
- Use main.py for the main application.

## Code Formatting
- Use 4 spaces for indentation.
- Use 80 characters for the maximum line length.

## Problem Solving
- Don't switch to Javascript solutions when fixing htmx issues.