Frontend upgrade for better design

[atxr]

Currently, all the components on the website are designed with raw CSS.
This is not very efficient, and because none of us is a web designer, this is also hard to get a clean result.

Many "design libraries" exist to make this task easier. They propose some basic components, easy to use and customizable, to avoid starting from scratch the web design.
MUI is one of the most famous, and often used with React.
I would like to include it in the frontend to make this task easier.

Also, this is a great time to think about a new design for the website if needed.
By new design, I'm mostly thinking about a new color scheme/font, and a new layout for the website.
Feel free to propose your dream design! We could also organize a meeting to decide this together.