Subtle media query problem

[OBXKH]

looking for help

please see

Document

at breakpoint 768px the drop down menu edges are not full, right and left. not taking up as much space than *all* the other pages

its subtle but its there

cant imagine this is too complicated

please help!

i would sincerely appreciate a block of code that fixes my problem and a coment how you fixed it... so i can learn from this

thank you!