Find more places where calc() is applicable

[halfmoonui]

Someone brought up a good point in another issue (https://github.com/halfmoonui/halfmoon/issues/55) that a few more variables can use the calc() function to make the framework even more extensible and easier to customize. That particular issue has been solved, however, I am creating this issue so that this is better addressed.

Please help me find other places where the calc() function is applicable (instead of hard-coding values). For reference, see the previously linked issue. In other words, comment on this issue if you think you have found a place where calc() is applicable. Thank you!