The CSS animations module lets you animate the values of CSS properties, such as background-position and transform, over time by using keyframes. Each keyframe describes how the animated element should render at a given time during the animation sequence. You can use the properties in the animations module to control the duration, number of repetitions, delayed start, and other aspects of an animation....animation-iteration-count to make the flakes fall repeatedly,... animation-direction to make the cloud move back and forth, animation-fill-mode...