fixed: sum/effect font-size to inherited from fixed 20px

[neilcamilleri]

• Please check if the PR fulfills these requirements

• We use semantic versioning (https://github.com/semantic-release/semantic-release to be specific), so follow https://github.com/angular/angular.js/blob/master/DEVELOPERS.md#-git-commit-guidelines EXCEPT, don't use 'feat:' if you're not me. Stepping major versions until 1.0 is a deliberate decision (after that, it'll be full semantic versioning.)
• Docs have been added / updated (for bug fixes / features)

• What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)
  Bug fix

• What is the current behavior? (You can also link to an open issue here)
  Fixed font-size for sum/effect dice roll

• What is the new behavior (if this is a feature change)?
  Font size inherited so it's scalable again

• Does this PR introduce a breaking change? (What changes might users need to make in their application due to this PR?)
  No

• Other information:

[neilcamilleri]

For some reason the whole css file was re-formatted with specifiers on multiple lines, but it did use the .prettierrc.yml in the repo to do so. Is it ok?

[xdy]

Apparently I have a formatter war going on without realizing it as I seldom touch the css files.
For now I'll turn off prettier on css files (I don't like that it bloated the file by moving each class to a separate line), and revisit formating css in #311
So, I'll merge your part of the css file, but remove the reformatting. (Or, rather, I'll let intellij/eslint do whatever it does by default, but nothing beyond that.)
Thanks!