Quick HTML/CSS animation task for a website

Hey everyone! I have a quick task for you - it won't take more than just a few hours, 5 stars guaranteed. I have a website [login to view URL] with automatic ads. When you click these ads, it should look exactly the same for all of them but right now some of these ads are opening without animation. I need this to be fixed. DO NOT SEND PROPOSALS UNLESS YOU HAVE ANALYSED THE PROBLEM