1. CSS Animation

    Complex method of animating certain properties of an element

  2. css at-rule: `@keyframes`

  3. css at-rule: `@keyframes`: ignore `!important` declarations

  4. css at-rule: `@keyframes`: named timeline range keyframe selectors

  5. css property: content-visibility: `@keyframe` animatable

  6. css property: display: `@keyframe` animatable