Minor Loris header CSS inaccuracies

[maximemulder]

Describe the bug

I did not see an issue for these, so here it is. These are several issues but they are so small that I think it is reasonable to group then into a single issue.

1. It is possible to open several dropdowns at once, by clicking one and hovering others.

2. It is possible for the header to have two lines by chosing the right window width.

3. The module categories are not correctly aligned. They are off by two pixels on the bottom side.

4. The title is not correctly aligned. It is up by two pixels from the bottom of the header.

Browser Environment:

• Browser: Firefox 123
• Version: 25 / Dev

Additional context

This is nothing urgent but I figured it would be good if it was written somewhere.

[alpeshjamgade]

HI, @MaximeMulder , Can I work on this?

[maximemulder]

To be honest, I mostly opened this issue with the idea of fully modernizing the header in the future rather than just fixing the style. The current code is very messy so I would advise against it.