This might help:
I completely disagree. JS injection is like Java in Vision. CSS is a cornerstone of Perspective, but perhaps because it's overshadowed by Perspective Styles configuration that this isn't made inherently obvious. Perspective Styles create CSS style rules. The Perspective Style editor, however, contains only a subset selection of the full array of available CSS properties though, and it's extremely useful to know some of the more useful CSS properties that aren't included in this, such as gap