Let me provide one warning to other Weeblers.
I'd started another draft, then clicked on the "Design" tool in the uppermost toolbar. That was a mistake, because that first draft disappeared.
Once I'd published this, I deleted the unlucky draft and went to the Design options for fonts.
The process is to click "Design". From there, "Themes" are obvious. The fonts for title and paragraph are selected from "Design Options", if my short-term memory works.
This is Lilly Font
Publish or Perish
Here's another warning.
Obviously the theme can change the background colour and text colour. That's fine and dandy.
But I chose the orange and green fonts for warnings and highlights in this theme. Some other theme might, for all I know, have a background that provides poor contrast. Be warned before making theme changes!