I once opened a design system file and found the same gray typed in by hand in more than a dozen places, each a few hex codes off. Rebranding meant fixing every layer one by one. Figma variables exist to end that, but only if you organize them on purpose. This post is how I build and manage variables for a mobile product design system with dark mode, along with the conventions I think are worth keeping. Three layers, one direction of reference. Start with the file structure...