init geek calc

README.md

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+# Geek Calculator
+
+A single-file, offline-capable calculator with a terminal-like interface. Features basic arithmetic operations, RPN mode, keyboard-first operation, and a "geek vibe" aesthetic.
+
+## Features
+
+- Basic arithmetic operations (+, -, ×, ÷)
+- Parentheses support for complex expressions
+- Percentage calculations
+- Positive/negative toggle (±)
+- RPN (Reverse Polish Notation) mode
+- Full keyboard operation
+- Command palette (access with @ key)
+- Calculation history with re-run capability
+- Terminal-themed UI with ASCII banner
+- Full offline capability
+- Keyboard accessibility (ARIA roles, focus indicators)
+
+## Usage
+
+### Basic Operations
+- Click buttons or use keyboard: `+`, `-`, `*`, `/`, `=` 
+- Use `Enter` to evaluate expressions
+- Use `Escape` to clear current input
+- Use `Backspace` to delete last character
+
+### RPN Mode
+- Toggle RPN mode with the RPN button
+- Enter numbers followed by operators
+- Example: To calculate `4 + 6`, enter: `4 ENTER 6 +`
+
+### Keyboard Controls
+- Numbers: `0-9`
+- Operators: `+`, `-`, `*`, `/`
+- Equals: `Enter` or `=`
+- Clear: `Escape` or `C`
+- Decimal: `.`
+- Backspace: `Backspace`
+- RPN Enter: `Enter` (in RPN mode)
+- Toggle RPN: `R`
+- Command Palette: `@`
+- History Navigation: `↑` and `↓`
+- Help: `?`
+
+### Command Palette
+- Press `@` to open the command palette
+- Type commands like "clear", "history", "theme", etc.
+
+## Offline Capability
+The calculator works completely offline. The first time you load it, it will cache all necessary files using a service worker.
+
+## Technical Details
+
+- Pure HTML/CSS/JavaScript (no external dependencies)
+- Total payload < 50KB
+- Uses ES6 modules for code organization
+- Service worker for offline functionality
+- LocalStorage for calculation history
+- Accessible with full keyboard navigation and ARIA roles
+
+## Development
+
+To run tests:
+1. Open `tests/index.html` in your browser
+2. Tests will run automatically
+
+## Architecture
+
+- `calculator.js`: Core calculator logic
+- `rpn-calculator.js`: RPN calculator implementation  
+- `ui.js`: User interface interactions
+- `state.js`: Application state management
+- `utils.js`: Utility functions
+- `styles.css`: All styling (dark theme, ASCII art, responsive)
+- `service-worker.js`: Offline functionality
+- `manifest.webmanifest`: PWA features
+
+## Size Budget
+The entire application is designed to stay under 50KB total payload.