Quality check

Calculator QA

The safe-to-spend calculator should handle empty fields, zero values, decimals, large values, invalid negatives, no negative result display, reset, presets, and privacy language.

Empty or invalid fields show an error. Negative values are rejected by validation. Unaffordable results show $0.00 remaining plus a positive shortfall, not negative currency. Decimal values format as USD. Reset returns result to neutral state. Presets load and calculate in browser only. Privacy note says calculations happen in browser.