Thank you. The use of tabs on a desktop (large screen) is great but falls short on a mobile screen. Your comment about the large margins is valid. To get a coloured background I used the Row Block inside of a column block and need to get rid of padding somewhere.
I am finding it a challenge to alter the design for desktop, tablet and mobile modes in the Gutenberg Block Editor and resort to the https://www.responsinator.com site to get some sense of the look. The alternative is use the the browser “Inspect” feature.
To be truthful, my problem is that I have become married to the design I had in mind and may have to abandon it for something better. That is easier said than done. Art was not my best subject in school.
Really appreciate your feedback. It’s what I needed.