Single vs. multiple DESIGN.md files within a project, is the spec opinionated?

Hi, I've been reading the specification carefully and the doc doesn't seem to take a stance on this, so wanted to ask directly.

Is a project meant to have one DESIGN.md, or can it have multiple?

In a real-world monorepo it's common to have multiple surfaces with different design languages:

my-project/
├── DESIGN.md
├── website/DESIGN.md
├── dashboard/DESIGN.md
├── docs/DESIGN.md
└── packages/ui/DESIGN.md
Each could have its own palette, typography, density, tone.

A more direct version of the question: if I have separate design rules for docs/ and dashboard/, should they live in one root DESIGN.md (e.g. as nested sections, or via metadata), or as separate DESIGN.md files in each directory? Which does the spec prefer?

• Root only, like AGENTS.md / CLAUDE.md, one canonical file describing the whole project.
• Per scope, free placement.. multiple files, agents pick the closest one to the file being edited.

So should tools look at root only or scan?

Start with the linked DESIGN.md specification and compare its current guidance with the root-only and per-scope layouts described in the issue. The work is complete when the specification explicitly states whether multiple DESIGN.md files are supported and how tools should discover or prioritize them.