Chrome Version       : 54.0.2840.98
OS Version: OS X 10.11.2
URLs (if applicable) :
Other browsers tested:
  Add OK or FAIL after other browsers where you have tested this issue:
     Safari 5: OK
  Firefox 4.x: OK
     IE 7/8/9: OK

What steps will reproduce the problem?
1. click on the button and hover box

What is the expected result?
the .main-gallery has a box-shadow property what shouldn't disappear

What happens instead of that?
the .main-gallery has a box-shadow property what is disappearing when I move my mouse over it or whit the button clicked fill it with an image from my JavaScript file


Please provide any additional information below. Attach a screenshot if
possible.

http://codepen.io/kowdermeister/pen/JbBBLZ

UserAgentString: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.98 Safari/537.36