Build a UI library that holds up inside a real product, not just on a sticker sheet. I tested MESH in WAYFIND, a project tool with issue review and handoff flows on desktop and mobile.
What I did
Colour, type and spacing foundations (31 variables)
488 reusable items in 14 categories
Component states, responsive layouts and handoff specs
One action, several states
Hover, focus, selection and disabled look and behave the same everywhere, so people learn a pattern once.
One library, two workflows
The same components connect issue review and handoff, with no one-off pieces made for a single screen.
Desktop and mobile, same rules
The layout changes, the hierarchy does not. Specs are ready for developers to pick up.