Enhance and Modernize the BMI Calculator UI with Responsive Design and Interactive Features 🎨

Hi There ,

I came across this BMI Calculator project and found it really interesting!
I’d love to contribute by improving and enhancing the frontend and overall user experience.

Here’s what I’m planning to do:
- Redesign the HTML structure for a cleaner and more modern layout.
- Apply a responsive design using modern CSS (Flexbox / Grid) for all screen sizes.
- Add better visual styling, animations, and a professional color theme.
- Improve the form UI/UX with input validation and error messages.
- Display BMI results dynamically with proper health status categories and color indicators.
- (Optional) Add a small info section or tooltip explaining BMI ranges and health tips.

The backend Flask logic will remain the same — my focus will be on making the UI more interactive and polished while keeping the code organized.

Could you please assign this issue to me so I can start working on it? 😊
I’ll make sure the final version looks clean, responsive, and beginner-friendly.

Thanks,
Ishwari Shinde