Could you please be more detailed? I didn't manage to let it work.

Here is the point 2) result:  It changed the collections' background, not the mega menu's one. Furthermore it didn't center the items in the menu.And sorry, another thing I would like to do here is to bolden the title of the lists in the menu ('First...

Here is the point 1) result:  The line is not extended for the entire lenght and it is not at the exact bottom of the header. Any tips to resolve this?

I'd like to resolve three things: 1) Add a black separator line below the header;2) Change mega menu background color and center the items in it3) I'd like the mega menu to open as I go on it with the cursor. I don't like arrows and click to open it....

I added the cose for video background. The problem is it is brought to front. For example, if I open the dropdown menu on mobile version, video background section ends up covering it.  

The solution you gave me works but the measurement had to be adjusted. I'd like to know how to shrink less the logo when scrolling down. I would like it to be roughly 60% of what it normally is.

 How can I put the highlited things to the sides. They are too centered.   

8a86ec.myshopify.comPassword: dahcko

Sorry but it doesn't work. Perhaps you should be still more detailed. I'm not an expert at all.

Can you be more specific, please? 

8a86ec.myshopify.comPassword: dahcko

How can I put the highlited things to the sides. They are too centered. 

Logo looks too small on the mobile version with respect to the desktop version. How can I make it bigger.Then, is it possible to regulate the degree to which logo get smaller when scrolling down?