Plain Css If.Changes

Draft 1.1

• Rename one of the two IfExpressions to IfConditionExpression to avoid a name collision.

• Allow ArbitrarySubstitions in place of not and in place of mixed clauses and operators.

• Explicitly indicate that IfGroup function calls syntax can't collide with SassCondition.

• Consider custom functions to be arbitrary substitution functions.

• Consider SassCondition to be an error in plain CSS.

• Require whitespace between identifiers and open parentheses.

• Indicate that string calculations in Special Numbers are a historical artifact rather than a living list.