fix: update postcss config to fix router scroll behavior

ref: vue-zone/vue3-vant-mobile#145

Author: cwandev

nuxt.config.ts

@@ -38,8 +38,11 @@ export default defineNuxtConfig({
         maxDisplayWidth: 600,
         // devtools excluded
         exclude: /@nuxt/,
-        appContainingBlock: 'auto',
         border: true,
+        rootContainingBlockSelectorList: [
+          'van-tabbar',
+          'van-popup',
+        ],
       },
     },
   },