diff --git a/apps/portal-shell/.postcssrc.json b/apps/portal-shell/.postcssrc.json
new file mode 100644
index 0000000..e092dc7
--- /dev/null
+++ b/apps/portal-shell/.postcssrc.json
@@ -0,0 +1,5 @@
+{
+  "plugins": {
+    "@tailwindcss/postcss": {}
+  }
+}
diff --git a/apps/portal-shell/postcss.config.js b/apps/portal-shell/postcss.config.js
deleted file mode 100644
index e564072..0000000
--- a/apps/portal-shell/postcss.config.js
+++ /dev/null
@@ -1,5 +0,0 @@
-module.exports = {
-  plugins: {
-    '@tailwindcss/postcss': {},
-  },
-};
diff --git a/docs/development.md b/docs/development.md
index 1a0fda1..e5b2232 100644
--- a/docs/development.md
+++ b/docs/development.md
@@ -21,7 +21,7 @@ apf_portal/
 │   ├── portal-shell/             # Angular 21 SPA (zoneless, standalone, Signals, Vitest, SCSS)
 │   │   ├── public/               # static assets
 │   │   ├── src/                  # entry, app config, routes, styles
-│   │   ├── postcss.config.js     # Tailwind PostCSS plugin
+│   │   ├── .postcssrc.json       # Tailwind PostCSS plugin (required by @angular/build esbuild — postcss.config.js is ignored)
 │   │   └── project.json          # Nx project config (build, serve, test, lint targets)
 │   ├── portal-shell-e2e/         # Playwright e2e for portal-shell
 │   ├── portal-bff/               # NestJS 11 BFF (Express adapter, ValidationPipe, Jest)