Hover Shadow

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.

A colored light halo appears around the element on hover.

Add a "Glow" hover effect (also called neon glow) to [where].
A soft colored halo should fade in around the element while the pointer is over it and fade out when it leaves: gentle, with no movement.
Keep the halo from affecting layout, and show the same effect on keyboard focus.

The element moves downward a few pixels on hover, as if pressed into the page.

Add a "Sink" hover effect to [where].
The element should move down a little and stay there while the pointer is over it, as if pressed into the page, and rise back when it leaves: smooth, with no bounce.
Move it visually without shifting the surrounding layout, and show the same effect on keyboard focus.

A translucent overlay tints the element to show the pointer is over it.

Add a "Hover State Layer" (also called hover state, state layer or hover overlay) to [where].
A faint translucent overlay in the content color should fade in quickly over the element while the pointer is over it, and fade out when it leaves.
Keep it faint so contrast stays intact, and use the same layer approach for focus and pressed states.

An icon drops out of view and comes back from above on hover.

Add an "Icon Drop" hover effect to [where].
The icon inside the element should drop down out of view and then fall back into place from above: quick, with a soft landing.
Play it once each time the pointer enters rather than looping, and keep the label and button size unchanged.

An icon drifts out of the button and fades while a new one floats in.

Add an "Icon Float Away" hover effect to [where].
The current icon should drift upward and fade out while a new icon floats up from below into its place, smoothly, and the swap should reverse when the pointer leaves.
Keep the button size fixed during the swap, and show the same effect on keyboard focus.