Hi,
The first one is actually a bug. I will make sure it’s fixed in the future. If you would like to avoid it right now (though it won’t affect anything on your page if you leave it), open “sm-core-css.css”, find the following:
font:0/0 serif;
and replace it with the following:
font:0px/0 serif;
The second one is caused by the use of CSS gradients in “sm-blue.css” which are still a W3C working draft. There is no way to avoid these errors, unless you remove all declarations that use the gradients. But again, you shouldn’t really worry about these errors too – they won’t affect anything on your page in any way.
Cheers!