CSS to create animation

I have a very newbie question in graphic/website design.

I plan on creating a website. In the website, on the initial page, while loading and also if it has loaded still for a certain duration I intend to have an animation going on.

Something similar to this one.

I am just learning that all of that could be done via CSS.

I wanted to know what sort of CSS do I need to learn to be able to create graphics like that because that doesnt seem like normal CSS.

Also, if I want to port the same interface to the mobile app (android or ios), can I just copy paste the CSS and get that working in Mobile app as well?