Currently, ranges with only 1 value or 3 values (or 2 for view-timeline) is not parsed properly (this is currently marked as TODO in the code). What also is not working is passing in normal as a value for range-start or range-end.

Examples that should parse:

• animation-range: normal (STL + VTL)
• animation-range: normal normal (STL + VTL)
• animation-range: normal 50% (STL)
• animation-range: normal exit 50% (VTL)
• animation-range: entry 50% normal (VTL)

Note that normal is not a valid range name, but a keyword that needs to be replaced with the normal value for the specific range part (start or end) for the type of timeline.