Question

If i have the following CSS:

.contactUsDiv label, input { display:block; }

Does that mean that ALL labels inside contactUsDiv elements will have block display & that ALL inputs inside the BODY will have block display?

OR

Does it mean that ALL labels AND inputs inside contactUsDiv elements will have block display?

Do I need to do this to get the latter to occur…

.contactUsDiv label, .contactUsDiv input { display:block; }

Answer 1

You need the latter to limit them both to .contactUsDiv. The comma starts a completely new selector.

.contactUsDiv label, input { display:block; }

Is the equivalent of:

.contactUsDiv label { display:block; }
input { display:block; }

And

.contactUsDiv label, .contactUsDiv input { display:block; }

Is the equivalent of:

.contactUsDiv label { display:block; }
.contactUsDiv input { display:block; }

W3 Specs on this are available here: http://www.w3.org/TR/css3-selectors/#grouping