cssString function
Converts a value to it CSS representation.
Implementation
String cssString(dynamic value) => switch (value) {
Color c => c.toSvgString(),
FontWeight w => w.toSvgString() ?? 'normal',
FontStyle s => s.toSvgString() ?? 'normal',
List<FontFeature> fs => fs.map((f) => f.toSvgString()).join(' '),
_ => value.toString(),
};