Function timing_css_vars 

pub fn timing_css_vars() -> String

Emit the whole time axis: a :root { … } block, then the motion-off block.

Mirrors makeover_geometry::geometry_css_vars. Like geometry and unlike colour, none of this varies at runtime, so a web consumer bakes it in at build time rather than applying it from JS on load.

The prefers-reduced-motion block rides with the values it overrides rather than being a second thing to remember to include. A consumer that took the vars and not the block would animate at every rung for a reader who asked it not to, and would do it silently.