First-pass contrast check: choose one representative component

Before checking an entire interface, choose a representative text component on its real background. Measure its default and lowest-contrast interactive states, then test a proposed color adjustment in both light and dark themes if supported. If transparency is involved, sample the rendered composite rather than the raw CSS token. This small pass verifies your method and catches the biggest mismatch before you expand the audit. It does not certify the rest of the product.