Added postcss config

postcss.config.js

@@ -0,0 +1,15 @@
+export default {
+  plugins: {
+    "postcss-import": {},
+    "postcss-preset-env": {
+      stage: 1,
+      features: {
+        "nesting-rules": false,
+      },
+    },
+    "postcss-utilities": {},
+    "postcss-nesting": {},
+    cssnano:
+      process.env.NODE_ENV === "production" ? { preset: "advanced" } : false,
+  },
+};