What CSS selector will work to change the body background image for all single posts in a certain category, using Wordpress 3.9 and Atahualpa 3.7.15?

The CSS solution provided in this thread: http://forum.bytesforall.com/showthread.php?t=20610

worked fine with Wordpress 3.5.2 and Atahualpa 3.7.12. Where the category name was "instructional videos," the following CSS code worked perfectly in those older versions of Wordpress & Atahualpa:

body.single.instructional-videos {
background-image: url("http://xxxx.jpg");
}

However, this does not work now with the newer versions of WP and Atahualpa referenced above.

After viewing the page source, I also tried:

body.single.category-instructional-videos {
background-image: url("http://xxxx.jpg");
}

But this also does not work.

"div.category-instructional videos" does work as a selector to change the background image of the post itself, but not the full body background.

Can't seem to find the correct CSS selector now to do what body.single.[category-name] did perfectly in the older versions of WP and Atahualpa referenced above.

Any help will be greatly appreciated!

The way to figure that out is to use a tool like the Firebug addon for Firefox.

Thank you, but I haven't yet learned to use Firebug. Will try to learn when I have a chance.

I was hoping that maybe someone may already have figured out what css selector will style the body background for all single posts in a certain category in Atahualpa 3.7.15 with Wordpress 3.9. I would think that this would not be site-specific; there should be a "generic" css selector for this that would work on all sites using these latest versions of Atahualpa and Wordpress. Yes?

The code I quoted above did work with the earlier versions of Atahualpa and WP mentioned above, but not now.

Would really appreciate help in this -- which may help others too!

Many thanks!

What is the URL of your site? Point to a single post page

Did you add the code you found in that other post back into the functions.php?

Hi Juggledad, Thank you for your reply. I just sent you a PM with the URL.

I added in ATO > CSS Inserts (not in the functions php) the CSS code that you helped me find for this purpose before - in the prior discussion thread (in July of 2013). That CSS code (placed in CSS Inserts) worked before - in the older versions of WP and Atahualpa mentioned above - but no longer works with the current versions of WP and Atahualpa.

Many thanks for your help!

The CSS won't work without the code added to function.php