Enhance UI design with modern layout and improved styling.

[Saloni-2005]

I have improved the UI/UX design for the main page of the ArduPilot Web Tools by implementing a modern and responsive layout. The changes include:

Updating the layout to use Flexbox for responsiveness.
Enhancing the visual appeal with a new color scheme, better spacing, and improved typography.
Adding hover effects and interactive elements for a more engaging user experience.
These changes are currently limited to the main page only. I would like to extend this work to the other connected pages to ensure consistency and a cohesive user experience across the platform.

This is how it looks like after modifying:

ezyZip.mp4

I kindly request @IamPete1 @Ryanf55 , to assign me this task so I can proceed with updating the other pages in line with the changes made to the main page.
"I kindly request your feedback and permission to extend these updates to the other pages for a consistent user experience."

Thank you for considering my contribution!