1. animationplaybackevent api: timelinetime

2. animationtimeline api

3. animationtimeline api: currenttime

4. animationtimeline api: duration

5. animation api: timeline

6. css property: animation-timeline

7. css property: animation-timeline: `scroll()`

8. css property: animation-timeline: `view()`

9. css property: animation: `animation-timeline` included in shorthand