Ask an AI coding agent to move a button 10 pixels left, and watch it struggle. CSS gives it five or six different ways to control position: margin, padding, a flex order, a grid column, a transform. Nothing says which one is actually in charge on this particular page, so the agent guesses, edits the wrong one, and something else quietly shifts. It reports the change as done. The page is now broken. QSS removes the guessing by removing the choice. Every element's position and size is one explicit number, not a tug-of-war between properties. Those numbers are written in a single unit, a "qnt" (1/1000th of the layout's own width), so the same edit holds its exact proportion at any screen size -- a phone, a laptop, a 4K display -- with no breakpoints, no media queries, and no separate rules to keep in sync. Move something once and it stays put, everywhere. That is the whole idea, and it helps humans exactly as much as it helps agents: fewer rules to maintain, one obvious place to make a change, and layouts that stay consistent across devices by construction instead of by discipline. QSS backs that up with two automatic auditors that catch mistakes a human reviewer might miss (a RED finding is a broken rule, ORANGE is a judgment call) and a real-browser render check, because a passing lint rule is not proof a page actually displays correctly -- only watching it render is. It ships compiled, ready-to-use CSS plus its SCSS source, works with zero JavaScript, and offers an optional JS engine for a few conveniences on top. It stays out of the way of whatever you use for colors, type and visual polish (Tailwind or anything else) -- QSS only ever owns position, size and structure. QSS was extracted from a real Rails development tool that still runs on it today, not built as a theoretical exercise. See docs/HOWTO.md to get started and docs/DESIGN_HISTORY.md for the full story of what was tried, what broke, and why each decision landed where it did. Status: 0.x. Expect names and APIs to change before 1.0.