RFR: JDK-8241544 update stylesheet for *-page CSS class rename and hyphenated naming

[Hannes Wallnöfer]

Should have read *unstyled* classes but autocorrect thought that’s not a word.

> Am 25.03.2020 um 16:50 schrieb Hannes Wallnöfer <hannes.wallnoefer at oracle.com>:
> 
> ... for those unsettled classes ...
>