The set is lightweight, visually consistent, and accessible.
Duotone by default: Icons that have a meaningful path/fill distinction are always duotone.
Outline when appropriate: Simple geometric icons such as +, /, or × do not receive a decorative background layer that would only reduce clarity.
Filled on demand: A filled variant is included only for icons that have a meaningful active or selected state, such as like, bookmark, or star, not as a blanket alternative style.
