This isn’t quite right. Parsing `none` values in the `list-style` shorthand is tricky, because you don’t always know what longhand they belong to when you see them. You have to count the number of nones you see and assign them after the fact.

Have a look at the [WeasyPrint code for this](https://github.com/Kozea/WeasyPrint/blob/39a3ee603acf932fe2e5a5fce3edc9bb2c8ac5ec/weasyprint/css/validation.py#L1458)