Why can't I enable Custom Stylesheets for Spaces?

[Ena Jenkins]

I am using the subscription based Confluence application hosted by atlassian.com.
I'd like to use Custom Stylesheets for Spaces but the option to turn it on is greyed out when I go to the admin section to enable. I am the admin for it and I created the account and the space - but for whatever reason, it seems only the system admin can make this change and I am not listed as the system admin. How do I change this or how do I enable CSS?

[BillA]

It's a restricted function in Confluence Ondemand. See https://confluence.atlassian.com/display/AOD/Restricted+Functions+in+Atlassian+OnDemand for details.

If you're using Confluence install then space admins have the ability to customise their space CSS.

[Felipevsw]

This is the updated link listing the functional differences in Confluence Cloud: https://confluence.atlassian.com/confcloud/functional-differences-in-confluence-cloud-734070955.html

[Jonathan Simonoff]

You must be a Confluence administrator to modify space layouts -- a space admin can't do it. That's never made sense to me, but that is the way it is.

UPDATE (correction) -- I think that was true for Confluence 3 (but now I'm not sure). It definitely is not right for Confluence 5.1 -- as noted in Bill's response, space admins for downloaded Confluence now certainly can change the layouts. (I tried it this time.) Assuming I'm right it used to be different. GREAT change. Sorry for the bad info.