<html> <head> <style>p:first-child {font-weight: bold;}</style></head> <body><div><p>I'm in</p><p>I'm not</p></div><div><div>I'm not even a paragraph</div><p>I'm not</p></div></body> </html> ]]>
Great! In this case, we're selecting all paragraphs that are, well, the first children of their parents.
While :hover is a valid pseudo-class, didn't we want to try :first-child?