A simple question: How do I reduce this spacing and how to change the background?
I think it is in the Options Inspector, but I cannot find the exact location to make the modification.
As for the background, how could I add images like this:
The gap in the first example may be controlled with the Option
CellFrameMargins. This can be done for one cell at a time or by creating a custom Style Sheet. Either is assisted by use of the Option Inspector.
Selecting your Title cell (use the selection bracket to its right), then opening the Option Inspector and searching for CellFrameMargins should show you something like:
The result of changing its value to