Apologies if this has been asked before, but can't track down something to this effect on the forums. I'd like to know please if there's a way of automatically adding a small image at the top of every page that falls into a particular category, on a wiki I'm admin for — i.e. as a visual shorthand, so when you see the page you immediately know that you're looking at something that comes under that subject area.
I've seen references before somewhere to applying distinct backgrounds (rather than the universal one) on some pages of a wiki, though was thinking more of just a thin horizontal line or similar before the text to 'colour-code' the page less intrusively. At present I was experimenting with adding a narrow coloured bar across the top of pages in the category, by making an empty div with a few pixels of padding, background colour and some box shadow effects, but was thinking of doing a screengrab of the effect then using this as an image file instead so as not to worry about browsers that can't handle box shadows, rounded corners etc. Then it occurred to me that rather than manually edit this code (either for the div or an image link) into 100+ pages individually, perhaps there's a way — via CSS, presumably, something I'm only just starting to get my head around — to ask the wiki to add it in automatically to pages that are listed in the category; the equivalent of using a template 'after the fact', so to speak...? Many thanks for any help!