@RbnJrg
Hi Jorge
Thanks so much for your help. I have really spent hours trying to do it and had given up. Your EPUB looks good. I will study it closely and look how it displays on Kobo and later how it goes to PDF with Prince.
ADE is OK. Prince too. The only thing, Kobo does not agree (text mixes with image), but Kobo is backward on so many fields with formatting, I find it hardly surprising.
The code cannot be more compact and clearer. Use of background,
background-size (I noted for this one to be careful) and boxes is really very convenient.