Background color on hover of second submenu

Hey hello,
I have 3 needs:

1) I need a help to change background colour on hover of the secondary top menu.
Please check on that page and watch the top menu on the top right corner name: “Organisateurs de séjour de Vacances”.
It has 4 submenus and nothing happens when hovering them.

What css code should I use in order to highlight the hover effect?

2) Also as you can see, submenus appear a bit on the left side of the top menu.
How can I center align the 4 submenus just underneath the top menu?

3) What would be the css code to change the size of the main and the second menu please?

Can’t wait to hear from you.
Thanks for your tips.

• This topic was modified 16 hours, 8 minutes ago by rvga.