ACCESSIBILITY
The defaults we don't make optional
Focus states, reduced motion, high contrast, and dark mode ship in Nucleus by default, not behind a flag.
Why these can't be opt-in
An accessibility feature a developer has to remember to enable gets left off under deadline pressure, every time. Nucleus ships focus states, reduced-motion handling, high-contrast support, dark mode, and native form controls as the default rendering: there's no flag to turn them on because there's no flag to forget.
The same rule applies to how we build the two live products: focus order and reduced-motion handling are checked as part of shipping, not audited afterward.
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