DO
Use #0A2540 (deep navy) for all primary text — never pure #000000
Apply brand indigo #635BFF to exactly one primary action per view
Use weight 300 for display headlines; weight 400 for all UI text
Set negative letter-spacing on all display and heading text
Use font-variant-numeric: tabular-nums for monetary and numeric data
DON'T
Use indigo accent for decorative purposes — reserve for interactive elements
Apply bold (600+) weights — authority comes from restraint, not heaviness
Use warm shadows — always use cool-toned rgba(10,37,64,...) shadows
Use border-radius above 16px on data-heavy containers
Rely on color alone to communicate status — always pair with text label