Switch to CSSNano for minification

package.json

@@ -15,10 +15,10 @@
     "@parcel/compressor-brotli": "^2.15.4",
     "@parcel/compressor-gzip": "^2.15.4",
     "@parcel/config-default": "^2.15.4",
+    "@parcel/optimizer-cssnano": "^2.15.4",
     "markdown-it-sup": "^2.0.0",
     "parcel": "^2.15.4",
     "postcss": "^8.5.6",
-    "postcss-custom-media": "^11.0.6",
     "posthtml": "^0.16.6",
     "posthtml-component": "github:StratusFearMe21/posthtml-components#reorder_processing",
     "posthtml-include": "^2.0.1",
@@ -28,5 +28,11 @@
     "audiomotion-analyzer": "^4.5.1",
     "htmx.org": "^2.0.6"
   },
+  "@parcel/transformer-css": {
+    "drafts": {
+      "nesting": true,
+      "customMedia": true
+    }
+  },
   "packageManager": "pnpm@10.11.0"
 }