Remove white space above header and below footer

Howdy,

I think I am going crazy! I’ve tried everything I can find on other support threads but can’t figure out how to remove that pesky white space above the header and below the footer on my site.

For reference, I’ve tried each of the following:

• .page .post-inner { padding-top: 0; }
• .wp-block-template-part { margin-top:0; }
• .page-template-template-cover #site-content .post-inner { padding-top: 0px; }

After adding the above to the “Additional CSS” tab in the Customizer, I am adding the CSS class to the element (the header). Nothing seems to change in any of the above cases.

I’m new to this, so if anyone can help me identify what I’m doing wrong, I would be so very grateful!

EDIT: RESOLVED

The page I need help with: [log in to see the link]