Originally Posted by Jellby
If that's the case, then ADE is just buggy and non-compliant. The CSS spec says unknown properties should just be ignored, they are a mistake of the creator, but don't make the stylesheet invalid.
A different situation is if you forget a colon or semicolon, or write "1.2fm" instead of "1.2em"...
Just the tag, not the whole stylesheet gets ignored. A typo, anywhere within the selector , seems to trigger this.
But in some case, who can tell
An early class in a cascade goes south and lots of things go into left field