SmartCalc Pro — Premium Smart Calculator

A premium, responsive, feature-rich smart calculator web application built with HTML5, CSS3, JavaScript (ES6+) and Bootstrap 5.3. It combines a glassmorphism / neumorphism UI with a safe, self-contained math engine, modern animations, accessibility support and a full suite of everyday tools.

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✨ Features

Area	Capabilities
Basic	+ − × ÷, percent, decimals, parentheses, negative numbers
Scientific	sin cos tan asin acos atan, √ ∛, squares/cubes/powers, ln log exp, factorial, absolute value, π & e, DEG / RAD modes
Memory	MC MR M+ M- MS (persisted to Local Storage)
History	Timestamps, live search, delete one / clear all, export JSON / CSV, copy, print, download
Keyboard	Numbers, operators, Enter, Esc, Backspace, Delete, arrow navigation, Ctrl+C/V, Ctrl+Z/Y, scientific shortcuts
Settings	Theme, font size, sounds, animations, shortcuts, auto-save / auto-clear history — persisted
Accessibility	Keyboard nav, focus rings, ARIA labels, screen-reader support, High-Contrast & Large-Font modes, reduced-motion support
Smart Tools	Unit converter, currency converter (Frankfurter API), percent, BMI, age, EMI loan, GST/VAT, date diff, random numbers, password generator
Voice	Voice input (Web Speech API) & spoken results (Speech Synthesis API)
UX	Animated loading screen, ripple & press effects, floating background, live result preview, auto-complete brackets, undo/redo, toast & SweetAlert notifications

Themes: Dark / Light / High-Contrast — persisted automatically.

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🚀 Getting Started

Option A — Local server (recommended)

Because the app uses browser APIs (Clipboard, fetch-to-Frankfurter, Local Storage), a small local web server gives the smoothest experience:

# from the project root
npx serve .
# or
python -m http.server 8080
# then open http://localhost:8080

Option B — Open directly in a browser

You can open index.html directly by double-clicking it. The app works, but note:

• The Print History feature opens a new window with about:blank (never the page URL) so it does not trigger Chrome's file:// “Unsafe attempt to load URL” security warning.
• Currency conversion needs internet access (uses the free Frankfurter API).
• CDN libraries (Bootstrap, GSAP, AOS, SweetAlert2, Toastify, icons) require an internet connection.

⚠️ Some browsers restrict Clipboard access on file://. Use a local server for the full experience.

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📁 Project Structure

calculator_Js/
├── index.html            # Main calculator single-page app
├── about.html            # About the project
├── help.html             # Help & keyboard shortcuts
├── assets/
│   ├── css/
│   │   ├── style.css         # Core layout & components
│   │   ├── themes.css        # Design tokens (light / dark / high-contrast)
│   │   ├── animations.css    # Keyframes, ripple, loading, micro-animations
│   │   └── responsive.css    # Mobile-first breakpoints
│   ├── js/
│   │   ├── theme.js          # Theme apply/persist + global toggle (every page)
│   │   ├── settings.js       # User preferences store + side-effects
│   │   ├── calculator.js     # Safe math engine (tokenizer + parser)
│   │   ├── memory.js         # MC/MR/M+/M-/MS memory hub
│   │   ├── history.js        # History CRUD, search, export
│   │   ├── keyboard.js       # Global keyboard shortcuts
│   │   └── app.js            # UI controller / wiring / utilities
│   ├── icons/  images/  sounds/
└── README.md

Module namespace: all modules register under the global CalculatorApp object, e.g. CalculatorApp.calculator, CalculatorApp.history, CalculatorApp.memory.

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🧮 The Math Engine

assets/js/calculator.js implements a tokenizer + recursive-descent parser — it never uses eval() or new Function. It supports:

• Arithmetic, unary minus, implicit multiplication (2(3+4), 2pi, 3sin(30))
• Right-associative power ^, postfix factorial ! (with a Lanczos gamma approximation for non-integer input)
• Degrees / radians for trigonometric & inverse functions
• Robust errors: division by zero, consecutive operators, unbalanced parentheses, overflow, NaN/Infinity, unknown symbols

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⌨️ Key Shortcuts (on the calculator page)

Key	Action
0–9 . + − * / ^ ( ) % !	Input
Enter	Calculate
Esc	Clear entry
Backspace / Delete	Delete / Clear all
← →	Move cursor
Ctrl+C/V Ctrl+Z/Y	Copy / Paste / Undo / Redo
S C T Q R L P E M	sin( cos( tan( sqrt( cbrt( ln( π e / toggle mode

Scientific key toggle is M.

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🛠 Customization

All settings live in Local Storage (calc_settings) and are applied instantly on index.html. The theme is stored separately (calc_theme) so it carries across all pages.

• Theme: navbar moon button cycles Dark → Light → High-Contrast.
• Font / animations / sound: toggle from the Settings panel or via user preference.
• History: calc_history key; memory uses calc_memory.

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🌐 Browser Support

Modern evergreen browsers (Chrome, Edge, Firefox, Safari). Uses CSS custom properties, backdrop-filter, IntersectionObserver, and the Web Speech / Clipboard APIs with graceful fallbacks.

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📄 License

MIT — free to use and modify.