Close gap between section and footer in Sydney theme

Please see example here, I have 10 pages with the same template and all are having the same issue that there is a gap between the footer and the last page section, can you help please?

Found a solution, changed gap colour to match footer background colour.

What can I do for my website? I did change many times in the style.css for the padding section (footer) but cant change the area and space between the footer and section.

Note: When I did editing during inspect element changes were shown but when I do with site there are no changes able to see.

Please help asap.