I'm working on a mobile website.

When I run the W3C CSS validator in CSS3 mode, I get about 78 errors.

When I run it again but I set the profile to "mobile", I get over 500 errors!

Most of the errors are of this type :
  • Property border-radius doesn't exist in Mobile but exists in [css3] : 0.7em 0.7em 0 0
  • Property box-sizing doesn't exist in Mobile but exists in [css3] : border-box
  • Unknown pseudo-element or pseudo-class :last-child
  • Property box-shadow doesn't exist in Mobile but exists in [css3] : inset 0 2px 0 #cccccc

I don't really understand, to me these CSS rules are OK to use. Worst case scenario they could generate a warning of some of the mobile browsers don't understand them but why give me errors?

The client is asking us to reduce the number of errors, and I think there are a few things we can improve indeed, but I have no intention of removing border-radius or box-shadow!

Thanks in advance for your help