Help with my navigation, please

[OBXKH]

please see

https://forallthetime.com/PRACTICE/index.html

and

https://forallthetime.com/PRACTICE/visit.html

having trouble with my nav covering the top of the main content, the content beneath the navigation

here

https://forallthetime.com/PRACTICE/visit.html

there is a gap at the top, black background color as well as the black border around the main content. plus my purple navigaton fills the entire width, while there is a small blackness beneath it and on top of it

yes, i have combed through my CSS looking for borders... what i found did not work

please tell me where my code issue is on both codes, how to fix it, and leave a comment so i can learn from this experience

i thank you!