🧮 Build a Smart Calculator Using HTML, CSS & JavaScript (With Keyboard Support)

💡 Description

This project is a clean and smart web-based calculator built using HTML, CSS, and JavaScript.
It doesn’t just look good — it behaves intelligently:
no operator spamming, supports negative numbers, and clears errors with one tap.

A perfect project if you’re learning DOM manipulation and JavaScript event handling.

🚀 Features

✅ Perform arithmetic operations → +, -, *, /, %
✅ Handles negative numbers → like -5+4
✅ Blocks invalid sequences like ++, */, etc.
✅ Shows "Error" on invalid inputs (deletes in one Backspace)
✅ Works with both buttons and keyboard
✅ Simple, responsive, and modern UI

🎨 UI Design:
The layout is built with minimal HTML and modern CSS —
a smooth gradient background, soft shadows, and clean button interactions make it feel polished.

You can easily tweak the theme colors or button styles to make it uniquely yours.

👉 Try it now on GitHub Pages

🌱 What You’ll Learn

• Handling keyboard events in JS
• Preventing invalid user inputs
• Real-time DOM updates
• Display error management
• Clean, responsive UI design

⚙️ Future Plans

🧩 Add Light/Dark mode toggle
🧮 Add Scientific functions (sin, cos, log, etc.)
📜 Add Calculation History
🌐 Connect custom domain (e.g., calculatorbynaman.tech)

💬 Final Thoughts

This isn’t just a calculator — it’s a clean demonstration of writing smart JavaScript logic with a responsive front end.
Try building your own version, or add more features to it!