Maybe my question wasn’t clear enough. For me as an (aged &) old-fashioned Pascal fan this php-css-stuff seems to be too far away from my modes of comprehension – I really can’t find the screw.
What I try to find out is how to link the condition of is_single (which is true inside of single.php) to the site-contents width (defined in custom.css). Or let me put it in Pascal terms:
If is_single then
site-content.width := 96 % // dont’t get_sidebar
else
begin
site-content.width := 66 %;
get_sidebar;
end;
There are lots of solutions documented for several themes, but apparently they don’t match the structure of Iconic One. Is this really such hard stuff?