Mobile Responsiveness UI

### Description
The PictoPy documentation website currently has responsiveness issues on smaller screen sizes.
On mobile and narrow viewports, content overflows horizontally and important UI elements
are partially hidden, making the documentation difficult to read and navigate.

This PR improves the responsive layout to ensure the documentation renders correctly
across different screen sizes.

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### Current Behavior
- Content overflows beyond the viewport width on mobile devices
- Horizontal scrolling is required to view full content
- Headings and text are partially cut off
- Navigation and content alignment break on small screens

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### Proposed Solution
- Improve responsive styles for smaller viewports
- Prevent horizontal overflow using proper container sizing
- Ensure content adapts correctly to screen width
- Adjust layout spacing and alignment for mobile devices

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### Testing
- Tested on mobile viewport using browser dev tools
- Verified no horizontal overflow
- Confirmed layout works on desktop and tablet views
- Ensured no functionality or navigation regressions

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### Impact
These changes significantly improve usability and accessibility of the documentation
for mobile users and enhance overall user experience.

I Want to work on it as a part of **Unstoppable** **Hackathon** please assign this issue to me