Use when tightening a site's visual system: too many font sizes, one-off colours, spacing, radii, button heights or icon sizes, or when someone says hairy styles, design units, count the units, or shot units. Measures every unit on the rendered page or the whole site, at phone and desktop, night and day; boxes each stray (the values a hair off) on a screenshot with the file and line that sets it; and plans how to condense the rest.