Parallax feel WP using plugins, My header disappears

my wp

When i crunch the size (not sure at what percent or or widtch it goes responsive) but the header disappears. I would have it stick in a fixed position on top. It was working, now it won’t. I tried disapbling all the plugins.

i’m not sure what css is being utilized to style the header. If i could at least get help with id’ing the stylesheet used, ( i can’t find any used in the install) and a snip of code to fix it to the top that’d be kickin!!!

Thanks 🙂