Pop

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.

The element smoothly scales up slightly when the pointer is over it.

Add a "Grow" hover effect (also called scale up) to [where].
The element should scale up slightly and smoothly while the pointer is over it, and shrink back when the pointer leaves: quick and subtle.
Keep the surrounding layout from shifting, and show the same effect on keyboard focus.

The element scales in a double-beat rhythm like a beating heart.

Add a "Heartbeat" effect (also called heart beat) to [where].
The element should swell and relax in a quick double beat, then rest briefly before the next beat, like a beating heart.
Loop it seamlessly with the rest kept between beats, and stop it for users who prefer reduced motion.

A count badge pops, bounces, or pulses when a new notification arrives.

Add a "Notification Badge Bounce" animation (also called a badge pop or ping) to [where].
When a new notification arrives, the count badge should pop in from nothing and settle with a couple of quick, springy bounces while a soft ring pulses out from it once.
Play it once per new notification rather than looping, and announce the new count to screen readers.

The element dips inward and returns, as if it were pushed like a physical button.

Add a "Push" hover effect to [where].
Each time the pointer enters, the element should dip smaller once quickly and spring back to its normal size, as if it were pushed in like a physical button.
Play it once per hover rather than looping, and keep the surrounding layout from shifting.

A colored circle grows from or shrinks toward the center to fill the element on hover.

Add a "Radial Fill" hover effect (also called circle expand) to [where].
A circle of the new color should grow smoothly from the center until it fills the element, and shrink back to the center when the pointer leaves, while the label color switches to stay readable.
Keep the circle clipped inside the element's shape and the label above it, and show the same effect on keyboard focus.

A rectangle expands or contracts inside the element to change its background on hover.

Add a "Rectangle Fill" hover effect to [where].
The new background color should close in from all four edges as an inner rectangle shrinks toward the center, and open back out when the pointer leaves, while the label color switches to stay readable: smooth and quick.
Keep the label above the fill, and show the same effect on keyboard focus.