Add a demo video + Improve code and design

[QuentinMacheda]

Explanation

Code and design improvements

• Enhance the CTA buttons with a better contrast (more modern, more readable, more accessible).
• Add color variables in the stylesheet to get more maintainable code and avoid errors.
• Update button layouts.
• Improve responsive design by adding media queries, using rem instead of pixels, etc...
• Update HTML tags for accessibility : main and footer tags.
• Adjust text alignment

Demonstration video

• Add an autoplayed and looped video to demonstrate sherlock project.

Result

Before	After