Hide on Scroll Header

A sticky header reduces in height or size after the user scrolls down.

Add a "Sticky Header Shrink" (also called a shrinking header or shrink on scroll) to [where].
The header should stay at the top and, once the reader scrolls down a little, smoothly shrink into a slimmer bar with a smaller logo, growing back when they return to the top.
Keep the content below from jumping while the header changes size.

The element glides out past a container edge and disappears.

Add a "Slide Out" exit animation (also called slide out up or slide out down) to [where].
The element should glide out past its container edge and disappear, staying fully opaque: quick, accelerating as it leaves.
Clip it at the container edge, hide it from keyboard and screen readers once it is out of view, and hide it instantly when the user prefers reduced motion (prefers-reduced-motion).

The element glides in from off its container edge to its resting position without fading.

Add a "Slide In" entrance animation (also called slide in left, slide in right, slide in up or slide in down) to [where].
The element should glide in from beyond its container edge to its resting place, fully opaque the whole time: quick, decelerating smoothly with no bounce.
Clip it at the container edge so it doesn't overlap neighbours or cause scrollbars while it is outside, and show it in place when the user prefers reduced motion (prefers-reduced-motion).

Vertical scrolling moves a pinned row of panels sideways.

Add a "Horizontal Scroll Section" (also called horizontal scrolling or a scroll-jacked horizontal gallery) to [where].
When the section reaches the top it should stay pinned while scrolling down moves its row of panels sideways, then release once the last panel is in view.
Tie the sideways movement directly to the scroll position so scrolling back reverses it, and fall back to a normal swipeable row on small screens or for users who prefer reduced motion.

Layers move at different speeds relative to scroll to create a sense of depth.

Add a "Parallax" scroll effect (also called parallax scrolling or parallax layers) to [where].
Background layers should move more slowly than the content as the page scrolls, the farthest layer moving least, for a subtle sense of depth.
Keep it tied to the scroll position without lag, keep text on the normal-speed layer, and turn the effect off for users who prefer reduced motion.

An element stays locked in place during a scroll range while other content or animation progresses.

Add a "Pinning" scroll effect (also called a pinned section or sticky section) to [where].
One panel should stay locked in place while the content beside it scrolls past, switching to match the step being read, and it should let go when the section ends.
Prefer native sticky positioning over hijacking the scroll, and make sure every step still reads well without the pinned panel on small screens.