Checkpoint: UI System Logic
Verify the module's reasoning at the logic level: token resolution order, a theme switcher reducer, and motion-preference handling.
The practices below run CSS through declaration checks and component logic through JS. The checkpoint verifies your reasoning: token cascade order, theme state handling, and reduced-motion policy as pure functions.
resolveTokens(scopes)— later scopes override earlier token by token.applyTheme(state, action)— a reducer for theme state with system fallback.motionPolicy(prefersReduced, userSetting)— decide the effective motion mode.
Why a UI checkpoint?
CSS knowledge is easy to fake in a tutorial and easy to test in review. The four checks here — token naming, container-query adaptation, motion respect, and contrast-aware state design — are the difference between styles that scale and styles that collapse at the next feature. They are also exactly what a senior reviewer looks for first.
Run them against your own SaaS dashboard build before you submit: name the
tokens you actually reused, prove one component adapts to its container, show
your prefers-reduced-motion block, and state your contrast pairs. If any
answer is "I did not check", you have found your next hour of work.