• Elements without a namespace (such as div) are no longer unified with elements with the empty namespace (such as |div). This unification didn't match the results returned by is-superselector(), and was not guaranteed to be valid.
• Support & within @at-root.
• Properly error when a compound selector is followed immediately by &.
• Properly handle variable scoping in @at-root and nested properties.
• Properly handle placeholder selectors in selector pseudos.
• Properly short-circuit the or and and operators.
• Support --$variable.
• Don't consider unitless numbers equal to numbers with units.
• Warn about using named colors in interpolation.
• Don't emit loud comments in functions.
• Detect import loops.
• Fix @import with a supports() clause.
• Forbid functions named "and", "or", and "not".
• Fix type-of() with a function.
• Emit a nicer error for invalid tokens in a selector.
• Fix invert() with a $weight parameter.
• Fix a unit-parsing edge-cases.
• Always parse imports with queries as plain CSS imports.
• Support & followed by a non-identifier.
• Properly handle split media queries.
• Properly handle a placeholder selector that isn't at the beginning of a compound selector.
• Fix more str-slice() bugs.
• Fix the % operator.
• Allow whitespace between = and the mixin name in the indented syntax.
• Fix some slash division edge cases.
• Fix not when used like a function.
• Fix attribute selectors with single-character values.
• Fix some bugs with the call() function.
• Properly handle a backslash followed by a CRLF sequence in a quoted string.
• Fix numbers divided by colors.
• Support slash-separated numbers in arguments to plain CSS functions.
• Error out if a function is passed an unknown named parameter.
• Improve the speed of loading large files on Node.
• Don't consider browser-prefixed selector pseudos to be superselectors of differently- or non-prefixed selector pseudos with the same base name.
• Fix an @extend edge case involving multiple combinators in a row.
• Fix a bug where a @content block could get incorrectly passed to a mixin.
• Properly isolate the lexical environments of different calls to the same mixin and function.