Take the MD3 colour layer from pmndrs/design-system

.changeset/md3-tier1.md

@@ -0,0 +1,9 @@
+---
+'@pmndrs/docs': minor
+---
+
+Take the Material Design 3 colour layer from `pmndrs/design-system` instead of maintaining it here. The hand-written `@theme` mapping and the shadcn remap — around 105 lines that had to be kept in step with the colour package by hand — are replaced by one registry item, `pmndrs/design-system/md3`, which brings its own Tailwind mapping and the config it maps. `react-mcu` gives way to `material-theme-builder`, so the CSS variables are now `--md-sys-color-*`; every `bg-surface` / `text-on-surface-variant` utility keeps working untouched, because the `--color-*` names on top of them are identical.
+
+The seed moves to poimandres mint (`#5de4c7`) — this is the visible change — and it now lives in exactly one place, the installed `src/lib/md3.ts`, rather than being restated in the layout and in two workflows. `THEME_PRIMARY`, `THEME_SCHEME` and `THEME_CONTRAST` still override it per deployment; a site that wants its own seed sets the workflow input, and one that doesn't inherits the pmndrs default.
+
+The five alert colours stay here, in `src/lib/mtb.ts`, which spreads the pmndrs seed and adds them. They are GitHub's palette and only this generator renders markdown alerts, so they are not the design system's to carry — but they are still harmonized against the seed, and `THEME_NOTE`, `THEME_TIP`, `THEME_IMPORTANT`, `THEME_WARNING` and `THEME_CAUTION` still work.

.github/workflows/build.yml

@@ -34,30 +34,33 @@ on:
         type: string
       discord:
         type: string
+      # Left empty on purpose: the pmndrs defaults live in src/lib/md3.ts, installed
+      # from pmndrs/design-system. Set one of these only to override the seed for a
+      # site — an empty value falls through to the shared default.
       theme_primary:
         type: string
-        default: '#323e48'
+        default: ''
       theme_scheme:
         type: string
-        default: 'tonalSpot'
+        default: ''
       theme_contrast:
         type: string
-        default: '0'
+        default: ''
       theme_note:
         type: string
-        default: '#1f6feb'
+        default: ''
       theme_tip:
         type: string
-        default: '#238636'
+        default: ''
       theme_important:
         type: string
-        default: '#8957e5'
+        default: ''
       theme_warning:
         type: string
-        default: '#d29922'
+        default: ''
       theme_caution:
         type: string
-        default: '#da3633'
+        default: ''
       docker_tag:
         type: string
         default: '3'

.github/workflows/ci.yml

@@ -114,14 +114,6 @@ jobs:
             --build-env LOGO=gutenberg.jpg \
             --build-env GITHUB="https://github.com/${{ github.repository }}" \
             --build-env DISCORD="${{ secrets.DISCORD }}" \
-            --build-env THEME_PRIMARY="#323e48" \
-            --build-env THEME_SCHEME="tonalSpot" \
-            --build-env THEME_CONTRAST="0" \
-            --build-env THEME_NOTE="#1f6feb" \
-            --build-env THEME_TIP="#238636" \
-            --build-env THEME_IMPORTANT="#8957e5" \
-            --build-env THEME_WARNING="#d29922" \
-            --build-env THEME_CAUTION="#da3633" \
             --build-env CONTRIBUTORS_PAT="${{ secrets.GITHUB_TOKEN }}" \
             > deployment-url.txt
 

components.json

@@ -18,5 +18,8 @@
     "lib": "@/lib",
     "hooks": "@/hooks"
   },
+  "rtl": false,
+  "menuColor": "default",
+  "menuAccent": "subtle",
   "registries": {}
 }

package.json

@@ -67,6 +67,7 @@
     "lodash-es": "^4.17.21",
     "lucide-react": "^0.563.0",
     "match-sorter": "^6.3.4",
+    "material-theme-builder": "^3.2.0",
     "mcp-handler": "^1.0.7",
     "mermaid": "^11.12.2",
     "next": "^16.1.3",
@@ -75,7 +76,6 @@
     "react": "^19.0.0",
     "react-dom": "^19.0.0",
     "react-icons": "^5.5.0",
-    "react-mcu": "^1.1.0",
     "rehype-github-alerts": "^3.0.0",
     "rehype-prism-plus": "^2.0.0",
     "remark-gfm": "^4.0.1",