Bob

The element rises upward a few pixels on hover, as if floating.

Add a "Float" hover effect (also called lift or raise) to [where].
The element should rise up a little and stay raised while the pointer is over it, then settle back when it leaves: smooth and gentle, with no bounce.
Move it visually without shifting the surrounding layout, and show the same effect on keyboard focus.

The element hops up and down with decelerating bounces.

Add a "Bounce" attention effect to [where].
The element should hop up and drop back down in a few quick bounces that get smaller each time, with a slight squash as it lands.
Play it once when triggered rather than looping, and skip it for users who prefer reduced motion.

The border color fades in or changes on hover.

Add a "Border Fade" hover effect to [where].
The border should fade smoothly from a muted tone to the accent color while the pointer is over the element: subtle, with no movement or size change.
Keep the border width the same in both states so nothing shifts, and show the same effect on keyboard focus.

Concentric border rings expand outward or contract inward from the element on hover.

Add a "Border Ripple" hover effect to [where].
When the pointer enters, a couple of border rings should spread outward from the element one after another and fade away: quick and light, like a ripple.
Play it once per hover rather than looping, and don't let the rings shift the surrounding layout.

The element scales with an elastic overshoot when hover starts or ends.

Add a "Bounce Scale" hover effect (also called bounce in / out) to [where].
The element should grow slightly larger with a springy, visible overshoot, briefly going past its final size before settling, and bounce back the same way when the pointer leaves.
Keep the surrounding layout from shifting, and show the same effect on keyboard focus.