Thanks for getting back to me, Chris.
I believe the problem lies with the @import path. I initially had done it as just:
@import "fontawesome";
@import "bootstrap";
@import "moodle";
As you know, that resulted in none of the core Moodle CSS appearing to work.
When I replaced my three lines with yours:
// Import FontAwesome.
@import "../../boost/scss/fontawesome";
// Import All of Bootstrap
@import "../../boost/scss/bootstrap";
// Import Core moodle CSS
@import "../../boost/scss/moodle";
It didn't appear to correct the issue and I am still not seeing the core Moodle CSS in effect.
A little Google-Fu and I learned that starting the @import with a / will take it to the root of the project and look from there, but this didn't work either:
// Import FontAwesome.
@import "/theme/boost/scss/fontawesome";
// Import All of Bootstrap
@import "/theme/boost/scss/bootstrap";
// Import Core moodle CSS
@import "/theme/boost/scss/moodle";
Is this because the custom preset file I uploaded is stored within the moodledata directory and not the Moodle root directory?
Attached is my custom preset file. Would you please take a peek and let me know if I'm missing something else?