Help please with gap + favourite section

[iphammer]

I want to create something similar to the design in the photo below where there is a gap between the columns and the background is slightly darker and when hovering over a column it pops out slightly. How do i do this?

Also is there a way of adding a favourites section for example when you click on the heart icon the domain is listed as a favorite in the header section if so how?

example site is Swetha .xyz

Thank you

This is my current page