Typography
Inter throughout, three weights, and line heights in even pixels rather than unitless multipliers — the vertical rhythm has to survive nesting inside dense control rows, and multipliers drift with font size.
Three registers, not one size ramp
Structure and explanation are two registers and should not be scaled together. 12px is not "14 one size smaller"; it is the step for paragraph helper text — line height 18 rather than 16, precisely because four lines of 12px on a 16px rhythm suffocate. Rescaling the whole system takes two groups of variables.
Build hierarchy with weight and colour, not size
Three layers inside a single 14px. What separates the field label from the value is one step of weight plus one of colour — clearer than adding another size, and it doesn't make the panel taller.
Section header 14/500 primary → field label 14/400 secondary → helper text 12/400 tertiary. Three layers, one size.