Massive change in approach.  It must be right because I deleted a lot more than I added.
Temporary placeholders for <div class=“example”> parts.
Temporary:   div.example { display: none; }
Sorting through what can be globally defined, and what must be under a breakpoint.
The class “example” for divs is gone forever.  Also cleaned up section “psyc380”.
div.example is no more.
<section id="psyc380"> - minor revision; don’t have time to do the major revision it needs.
Mostly cleaning out the cruft, and straightening comments.  I expect to merge this branch back in soon.
Converting the breakpoints to em units.  Minor comments clean-up.