From 2e0f552e3993ce8303d38848d330c1ce6a39d9ea Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 23 Jan 2026 21:39:03 +0000
Subject: [PATCH 1/3] Initial plan


From 20ade5b6231e97497f39604e747efe81b2332427 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 23 Jan 2026 21:43:13 +0000
Subject: [PATCH 2/3] Migrate from PostCSS to Lightning CSS

Co-authored-by: nichoth <5776508+nichoth@users.noreply.github.com>
---
 package.json   | 12 ++++--------
 vite.config.js | 12 ++++++------
 2 files changed, 10 insertions(+), 14 deletions(-)

diff --git a/package.json b/package.json
index a416321..3678ccd 100644
--- a/package.json
+++ b/package.json
@@ -31,8 +31,8 @@
     "test": "npm run build && npm run build-tests && npm run test-tape-run",
     "test-tape-run": "cat test/index.html | tape-run --input=html --static=test | tap-spec",
     "build-tests": "esbuild test/index.ts --target=es2020 --bundle --keep-names > test/test-bundle.js",
-    "build-css": "postcss src/index.css --use postcss-nesting > dist/index.css",
-    "build-css:min": "postcss src/index.css --use cssnano postcss-nesting > dist/index.min.css",
+    "build-css": "lightningcss --nesting --bundle --targets '>= 0.25%' src/index.css -o dist/index.css",
+    "build-css:min": "lightningcss --nesting --bundle --minify --targets '>= 0.25%' src/index.css -o dist/index.min.css",
     "build-cjs": "esbuild src/*.ts --format=cjs --keep-names --tsconfig=tsconfig.build.json --outdir=./dist --out-extension:.js=.cjs --sourcemap",
     "build-esm": "esbuild src/*.ts --format=esm --metafile=dist/meta.json --keep-names --tsconfig=tsconfig.build.json --outdir=./dist --sourcemap && tsc --emitDeclarationOnly --project tsconfig.build.json --outDir dist",
     "build-esm:min": "esbuild ./src/*.ts --format=esm --keep-names --bundle --tsconfig=tsconfig.build.json --minify --out-extension:.js=.min.js --outdir=./dist --sourcemap",
@@ -46,22 +46,18 @@
     "postversion": "git push --follow-tags && export $(cat .env | xargs) && npm publish",
     "prepublishOnly": "npm run build"
   },
-  "dependencies": {},
   "devDependencies": {
-    "@substrate-system/dom": "^0.1.7",
     "@substrate-system/debug": "^0.9.0",
+    "@substrate-system/dom": "^0.1.7",
     "@substrate-system/tapzero": "^0.10.13",
     "@typescript-eslint/eslint-plugin": "^8.7.0",
     "@typescript-eslint/parser": "^8.7.0",
     "auto-changelog": "^2.4.0",
-    "cssnano": "^7.0.3",
     "esbuild": "^0.27.0",
     "eslint": "^8.57.0",
     "eslint-config-standard": "^17.1.0",
+    "lightningcss-cli": "^1.31.1",
     "markdown-toc": "^1.2.0",
-    "postcss": "^8.5.1",
-    "postcss-cli": "^11.0.0",
-    "postcss-nesting": "^13.0.1",
     "stylelint": "^16.9.0",
     "stylelint-config-standard": "^39.0.0",
     "tap-spec": "^5.0.0",
diff --git a/vite.config.js b/vite.config.js
index e756b35..fc21659 100644
--- a/vite.config.js
+++ b/vite.config.js
@@ -1,5 +1,4 @@
 import { defineConfig } from 'vite'
-import postcssNesting from 'postcss-nesting'
 
 // https://vitejs.dev/config/
 export default defineConfig({
@@ -13,11 +12,12 @@ export default defineConfig({
     },
     publicDir: '_public',
     css: {
-        postcss: {
-            plugins: [
-                postcssNesting
-            ],
-        },
+        transformer: 'lightningcss',
+        lightningcss: {
+            drafts: {
+                nesting: true
+            }
+        }
     },
     server: {
         port: 8888,

From fcecc485e7c4fd7ad48082131ff061e2f6e4330d Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 23 Jan 2026 21:45:11 +0000
Subject: [PATCH 3/3] Add lightningcss package for Vite integration

Co-authored-by: nichoth <5776508+nichoth@users.noreply.github.com>
---
 package.json | 1 +
 1 file changed, 1 insertion(+)

diff --git a/package.json b/package.json
index 3678ccd..d11936d 100644
--- a/package.json
+++ b/package.json
@@ -56,6 +56,7 @@
     "esbuild": "^0.27.0",
     "eslint": "^8.57.0",
     "eslint-config-standard": "^17.1.0",
+    "lightningcss": "^1.31.1",
     "lightningcss-cli": "^1.31.1",
     "markdown-toc": "^1.2.0",
     "stylelint": "^16.9.0",