# Simple Calculator

Greenfield project. Implementation is driven by the Vexa AI-SDLC pipeline (Jira project TSC).

## Project Structure

```
/
├── index.html      # Calculator UI (semantic HTML5)
├── styles.css      # Responsive CSS layout and styling
├── package.json    # Dev dependencies and npm scripts
├── eslint.config.js # ESLint flat config (TypeScript + React rules)
├── tsconfig.json   # TypeScript compiler config (strict mode)
├── .prettierrc     # Prettier formatting config
├── README.md       # Project overview
└── CLAUDE.md       # This file
```

## Build Commands

No build step configured yet. Install dependencies with:

```bash
npm install
```

## Test Commands

No test suite has been configured yet. Update this section once testing infrastructure is in place.

## Development Commands

No dev server or REPL is configured yet. Update this section once the implementation begins.

## Lint and Format Commands

```bash
npm run lint          # Run ESLint
npm run format        # Format all files with Prettier
npm run format:check  # Check formatting without writing (CI)
```

## Architecture Notes

- **Domain**: Simple Calculator — arithmetic operations (add, subtract, multiply, divide at minimum).
- **Stack**: Plain HTML/CSS/JS — no framework or build step.
- `index.html` contains the full UI structure: operand inputs, operation buttons, calculate/clear buttons, result `<output>`, and an error `<p role="alert">`.

## Code Style

- **Linter**: ESLint v9 (flat config) with `typescript-eslint` recommended rules, `eslint-plugin-react`, `eslint-plugin-react-hooks`, and `eslint-config-prettier`.
- **Formatter**: Prettier — single quotes, 2-space indent, ES5 trailing commas, 80-char line width.
- **TypeScript**: `strict: true` enabled in `tsconfig.json`.