Decorated with Animatable, if applicable
Included initial keyword
Included CSSInitialValue
Implemented Reset method
Updated tests to check for initial value
Added tests for the initial keyword
Allow non-inherited (by default) elements to be inherited
Improved columns property (not relying on shorthands)
Removed longhand dependencies of margin
Removed longhand dependency of padding
Simplified compound implementations
Removed dependency on longhand properties
Simplified the border-image-width data structure