W3C CSS syntax for pseudo element in meta

[multidots1896]

I have checking in meta sites, and moving in buddypress.org in that bb-base theme has found a pseudo element structure in style.css file.
on their for pseudo element like :after and :before single-colon syntax was used but this type of syntax was used in CSS1 and CSS2.
In latest CSS3 level we used double colon notation for pseudo element (::after and ::before).

[multidots1896]

added patch for this ticket where i modify css

[dd32]

This isn't the only case where single-colons are used, ​https://css-tricks.com/to-double-colon-or-not-do-double-colon/ is a good article about it - put simply, it doesn't matter if it's single or double really.

Since the work is done, no harm in committing it though.