Function invalidate_caches 

pub fn invalidate_caches()

Reset all process-wide caches so the next call to system_is_dark(), prefers_reduced_motion(), or system_icon_theme() re-queries the OS; a cached failure to detect the icon theme is cleared too.

Call this when you detect that the user has changed system settings (e.g., dark mode toggle, icon theme switch, accessibility preferences).

The detect_*() family of functions are unaffected — they always query the OS directly.