What you have validated here is CSS. Quick answer: ignore all of these warnings and errors.
Longer answer: Much of CSS used by plugins & theme is not standardized YET, that is why you get warnings mentioning this. Officials just move much slower then browser developers.
Comments
What you have validated here is CSS.
Quick answer: ignore all of these warnings and errors.
Longer answer:
Much of CSS used by plugins & theme is not standardized YET, that is why you get warnings mentioning this. Officials just move much slower then browser developers.
HTML validation is more important then CSS.
With kind regards.