I audited 20 design systems for spacing drift. Here is what your team can use from it.

Nobody on your team chose 13px. Someone pasted it. Someone nudged 12px until a border lined up. A coding agent produced it because nothing told it your scale stops at 12 and 16. .card { padding : 13px ; /* off-scale: nearest are 12px or 16px */ margin-bottom : 7px ; /* off-scale: nearest are 4px or 8px */ } Six months later git grep finds forty distinct spacing values, and the design system's spacing page describes a project that no longer exists. This spring I pointed Rhythmguard , the Stylelint plugin I maintain for spacing scales, at twenty public design systems to find out how quiet it could be on code I do not control. The numbers changed the tool more than any feature request has. This is what a team can take from them, whether or not you use this plugin. Part 1. What twenty repositories showed The benchmark clones each repository at a pinned commit, runs the audit, and classifies every finding as real drift or as noise the tool should not have raised. The full table lives in QUIET_BENCHMARK.md and CI regenerates it on every change. A slice: Repo Off-scale findings Scale source Note Mastodon 564 its own --space-* tokens see below Carbon 272 fallback spacing goes through spacing() Primer CSS 97 fallback tokens arrive from a package shadcn/ui 58 its own Tailwind --spacing base Bootstrap 41 fallback spacing goes through $spacer Mantine 30 its own --mantine-spacing-* tokens Radix Themes 7 its own --space-* tokens values written as calc(4px * var(--scaling)) Spectrum CSS 5 fallback everything is a --spectrum-* token Three things held across the set. Drift concentrates in a handful of values Mastodon defines a real spacing scale as custom properties: // app/javascript/styles/mastodon/tokens/_shape.scss --space-3xs : 2px ; --space-xs : 8px ; --space-sm : 12px ; --space-md : 16px ; --space-lg : 20px ; --space-xl : 24px ; --space-4xl : 36px ; --space-5xl : 40px ; Its stylesheets ignore that scale 564 times. Here is the audit's own histogram: ## CSS Off-Scale Values | V