Scroll Action + Fixed Elements

Hey gang-

I have a scene with a Fixed Header and Footer (via DBear’s technique ) but they first fill up the screen and then animate to their Header/Footer positions when the user scrolls. This is via a Trigger that detects Viewport Entry/Exit. Except of course it doesn’t work. Let me first describe the page:

This is landing page:

Note the Header and Footer scale to fill the Viewport, and the Trigger would move away when you Scroll.

When you scroll, an Animation takes you to this:

In this case, the Footer disappears, and the header is locked. The content + Trigger would be scrolled off-screen.

(one more side concern: using DBear’s Fixed technique, the scroll bars disappear, but they leave a white gutter.)

However, the resulting action is poorly-triggered animation when scrolling back up and down (it doesn’t seem to recognize the re-entry), as well as less-than-ideal positioning of the elements.

Thank you all of input, truly appreciated. (21.5 KB)