Invisible text in some sections

## Location within the Book

* Book build date (Is the date on page 1): 2020-08-21
* Book format (PDF, Epub or Mobi): Epub
* Chapter or Appendix: Every Cheese
* Section: 15
* Subsection: 3
* What operating system are you using:
- [ ] Linux (Ubuntu 20.04)
- [ ] Linux (Ubuntu 18.04)
- [ ] Linux (Other)
- [x] MacOS Catalina 10.15.6 (19G2021)
- [ ] MacOS Mojave
- [ ] MacOS Big Sur
- [ ] Windows 10 Pro, Version 2004 or higher
- [ ] Windows 10 Pro, Version 1909 or lower
- [ ] Windows 10 Home, Version 2004 or higher
- [ ] Windows 10 Home, Version 1909 or lower

## Description
The "what to type" examples cannot be seen in this chapter and following sections.
some of the text is visible in some following sections. I changed fonts and display theme and could not get the text to appear.

Section 15-3:
“Create a new Conda environment called everycheese configure it to use python3.8:

conda create -n everycheese python=3.8. <=== invisible
Activate the everycheese Conda environment:

conda activate everycheese. <=== invisible
After that, our command-line should look like something like:

(everycheese) $
”

this section 16.2 appears while previous section 15 text is not visible
“At the command line, type:
conda install -c conda-forge cookiecutter
”

## Possible Solutions

## Your full name so we can provide accurate credit within the book
Henry Sautter
hank@sautter.photography