How to add box-shadow to :hover of slider thumbnail?

Question

css

The slider itself
https://www.jssor.com/byfbir/image-gallery-with-ve...
On the left of the thumbnail
, I can’t figure out how to make it so that there would be a box-shadow on hover.

Answer 1

this is because you have overflow:hidden on the parent div, and therefore nothing gets out of its borders
https://codepen.io/anon/pen/VOWBmz

Answer 2

Selector:hover {
  box-shadow....
}