Front page refreshed design 2023

[delestro]

Some adjustments to the CSS code, so that the front page looks more fresh and clean.

This is the new expected layout after this merge:

The main changes are:

• Navigation bar lighter, and with fade animations
• Shorter header with a smaller logo
• Logo and search field are more centralized on the page
• Search bar redesign, with a button for advanced search
• Card style for the "recent" and "most viewed" tools

Future work is still needed, especially for the advanced search page. The input fields still need some styling and reorganization.

[miura]

looks more modern and great to me. Great work!
what do you think @PerrineGilloteaux , @czhci ?