cant remove space under menu navigation bar

HI,
I’ve looked through the forum and tried all the suggestions to be able to remove the space that is under the navigation bar and above the slider.

I’ve attached screen images of the main page where the gap is and the CSS that I copied in and the design option changes suggested in other posts. there’s a hazard shape next to each of the css lines that says “Use of !important”.

The website I’m building is:

Home

if it helps to see it.