fine I'll do it

config/_default/hugo.toml

@@ -68,6 +68,8 @@ enableEmoji = true
 
 [permalinks]
   [permalinks.page]
-    posts = "/:year/:month/:filename"
+    posts = "/posts/:year/:month/:slug"
+    series = "/:year/:month/:slug"
   [permalinks.section]
-    posts = "/"
+    posts = "/posts/"
+    series = "/series"