CSS animations allow you to build complex animated sequences. Adriano. 1.4. You can change as many CSS properties you want, as many times you want. I generate a solid shadow using the box-shadow property, normally you will want to write in browser prefixes for border-radius and box-shadow, but I trimmed that code to keep things brief. 2. an optional name for the animation, which may be none, a , or a 3. zero, one, or two