Hi, I'm a newbie.
I want the navbar fixed to the top, but also to move up 30px on scroll up from 50% of hero.
I can get it to move up, but then when the hero scrolls out of view, the navbar moves back down.
How do I get it to:
1. Stay up, once it's moved up?
2. Move back down, when 50% of hero scrolls back down?