Found it:
#main {background-color:transparent;}
Done!
Sorry -I did not understand your post.
So far I managed to make the header transparent by adding the following line:
#header {background-color:transparent;}
to the custom CSS window under ‘Mantra Settings’.
I’m looking for a similar bit of CSS to now make the content background transparent, leaving only the featured images to scroll up and down over the background image.
Is there a simple line or two of CSS to do this?
Thanks,