# Nepal Income Tax Calculator (FY 2083/84 & FY 2082/83)

A modern, high-performance, progressive web application (PWA) designed for calculating and comparing income tax liabilities, monthly cash-in-hand (take-home salary), Cost to Company (CTC), and retirement wealth accumulation across Nepal's income tax regimes: **FY 2083/84 (Unified Slabs)** vs **FY 2082/83 (Single/Married Slabs)**.

## Features

- **FY 2083/84 Default Unified Slabs**: Features the new single unified tax schedule (NPR 1,000,000 tax-free slab for SSF contributors) active by default.
- **Social Security Fund (SSF) 1% SST Waiver**: Automatically waives the 1% Social Security Tax on the first slab when SSF is enabled.
- **Real-Time Dynamic Calculations**: Updates all monthly/annual cash-in-hand, income tax, CTC, and retirement contribution descriptions live on every keystroke.
- **Comparison & Dual-Profile Analysis**: Compare FY 2082/83 vs FY 2083/84 side-by-side or analyze two custom salary offer structures simultaneously.
- **Tax Optimization Advice**: Smart recommendation engine identifying unused insurance exemptions (Life/Health), approved medical credits, and CIT contribution limits to minimize tax liability.
- **Visual Analytics**: Interactive SVG donut chart showing income distribution (Take-home vs Tax vs Savings) and progressive slab visualizer bars.
- **Theme Synchronization**: Full Light / System / Dark theme toggle with persistent user preferences.
- **Print & PDF Report**: Clean 1-page print stylesheet formatted for exporting calculation reports.
- **PWA & Offline Ready**: Fully functional offline web application with service worker caching.

## Usage

1. Open `index.html` in any web browser or visit the live deployment.
2. Enter your **Monthly Basic Salary** and **Monthly Allowances**.
3. Toggle options for **SSF (31%)**, **EPF (20%)**, **Deposit Gratuity to CIT Fund (8.33%)**, and voluntary **Monthly CIT**.
4. View instant results for monthly take-home cash, annual tax, CTC, and total retirement savings.

## Project Structure

```
nepal-tax-calculator/
├── index.html       # HTML5 semantic UI with glassmorphism layout & SEO tags
├── style.css        # CSS Design System with light/dark tokens & print styles
├── app.js           # Main controller, state management, event delegation & UI bindings
├── calculator.js    # Pure tax calculation engine with exact slab rules & deductions
├── sw.js            # PWA Service Worker for offline asset caching (v12)
├── manifest.json    # PWA Web Application Manifest
├── icon.svg         # SVG Application Icon
└── README.md        # Dedicated User Manual & Documentation
```

## Attribution & License

Made with ❤️ in 🇳🇵 by Alok - hello@aloks.com.np