diff --git a/moon.mod.json b/moon.mod.json
index 4aef08c..bce27ad 100644
--- a/moon.mod.json
+++ b/moon.mod.json
@@ -2,13 +2,15 @@
   "name": "respo/app",
   "version": "0.1.0",
   "deps": {
-    "tiye/respo": "0.0.35",
-    "tiye/dom-ffi": "0.0.9"
+    "tiye/respo": "0.1.0",
+    "tiye/dom-ffi": "0.2.0",
+    "tiye/respo_css": "0.1.2"
   },
   "readme": "README.md",
   "repository": "",
   "license": "Apache-2.0",
   "keywords": [],
   "description": "",
-  "source": "src"
+  "source": "src",
+  "preferred-target": "js"
 }
diff --git a/src/main/counter.mbt b/src/main/counter.mbt
index afc02bb..d7ccb9d 100644
--- a/src/main/counter.mbt
+++ b/src/main/counter.mbt
@@ -1,8 +1,11 @@
 ///|
-typealias @respo_node.(RespoEvent, RespoNode, DispatchFn, RespoCommonError)
-
-///|
-fnalias @respo_node.text_node
+using @respo_node {
+  text_node,
+  type RespoEvent,
+  type RespoNode,
+  type DispatchFn,
+  type RespoCommonError
+}
 
 ///|
 struct MainState {
@@ -12,14 +15,14 @@ struct MainState {
 ///|
 fn comp_counter(
   states : @respo.RespoStatesTree,
-  global_counted : Int
+  global_counted : Int,
 ) -> RespoNode[ActionOp] {
   let cursor = states.path()
   let state = (states.cast_branch() : MainState)
   let counted = state.counted
   let on_inc = fn(
     e : RespoEvent,
-    dispatch : DispatchFn[ActionOp]
+    dispatch : DispatchFn[ActionOp],
   ) -> Unit raise RespoCommonError {
     @dom_ffi.warn_log("inc click: \{e}")
     if e is Click(original_event~, ..) {
@@ -31,7 +34,7 @@ fn comp_counter(
   }
   let on_dec = fn(
     e : RespoEvent,
-    dispatch : DispatchFn[ActionOp]
+    dispatch : DispatchFn[ActionOp],
   ) -> Unit raise RespoCommonError {
     @dom_ffi.warn_log("dec click: \{e}")
     dispatch.run(Decrement)
@@ -40,7 +43,7 @@ fn comp_counter(
   }
   let on_inc_twice = fn(
     e : RespoEvent,
-    dispatch : DispatchFn[ActionOp]
+    dispatch : DispatchFn[ActionOp],
   ) -> Unit raise RespoCommonError {
     @dom_ffi.warn_log("twice click: \{e}")
     dispatch.run(IncTwice)
diff --git a/src/main/main.mbt b/src/main/main.mbt
index ea29d88..cdd2f66 100644
--- a/src/main/main.mbt
+++ b/src/main/main.mbt
@@ -1,12 +1,15 @@
 ///|
-fnalias @respo_node.(div, span, button, respo_style)
+using @respo_node {div, span, button}
+
+///|
+using @css {respo_style}
 
 ///|
 let app_store_key : String = "mbt-workflow"
 
 ///|
 fn view(
-  store : Store
+  store : Store,
 ) -> @respo_node.RespoNode[ActionOp] raise @respo_node.RespoCommonError {
   if false {
     raise @respo_node.RespoCommonError("TODO")
@@ -21,23 +24,24 @@ fn view(
 ///|
 fn main {
   let window = @dom_ffi.window()
-  let mount_target = window
-    .document()
-    .query_selector(".app")
-    .reinterpret_as_node()
-  let app : @respo.RespoApp[Store] = {
-    store: Ref::new(@respo.try_load_storage(app_store_key)),
-    mount_target,
-    storage_key: app_store_key,
+  if window.document().query_selector(".app") is Some(mount_target) {
+    let mount_target = mount_target.reinterpret_as_node()
+    let app : @respo.RespoApp[Store] = {
+      store: Ref::new(@respo.try_load_storage(app_store_key)),
+      mount_target,
+      storage_key: app_store_key,
+    }
+    app.backup_model_beforeunload()
+    // @dom_ffi.log("store: " + app.store.val.to_json().stringify(indent=2))
+    app.render_loop(fn() { view(app.store.val) }, fn(op) {
+      @dom_ffi.log("Action: \{op}")
+      app.store.val.update(op)
+    })
+    let dev_mode = @dom_ffi.new_url_search_params(window.location().search()).get(
+      "mode",
+    )
+    @dom_ffi.log("dev mode: \{dev_mode}")
+  } else {
+    @dom_ffi.log("No mount target found")
   }
-  app.backup_model_beforeunload()
-  // @dom_ffi.log("store: " + app.store.val.to_json().stringify(indent=2))
-  app.render_loop(fn() { view(app.store.val) }, fn(op) {
-    @dom_ffi.log("Action: \{op}")
-    app.store.val.update(op)
-  })
-  let dev_mode = @dom_ffi.new_url_search_params(window.location().search()).get(
-    "mode",
-  )
-  @dom_ffi.log("dev mode: \{dev_mode}")
 }
diff --git a/src/main/moon.pkg.json b/src/main/moon.pkg.json
index 837b236..59ac124 100644
--- a/src/main/moon.pkg.json
+++ b/src/main/moon.pkg.json
@@ -2,13 +2,14 @@
   "is-main": true,
   "import": [
     {
-      "path": "tiye/respo/lib",
+      "path": "tiye/respo",
       "alias": "respo"
     },
     {
-      "path": "tiye/respo/lib/node",
+      "path": "tiye/respo/node",
       "alias": "respo_node"
     },
-    { "path": "tiye/dom-ffi/lib", "alias": "dom_ffi" }
+    { "path": "tiye/dom-ffi", "alias": "dom_ffi" },
+    { "path": "tiye/respo_css", "alias": "css" }
   ]
 }
diff --git a/src/main/store.mbt b/src/main/store.mbt
index 0110139..9372aba 100644
--- a/src/main/store.mbt
+++ b/src/main/store.mbt
@@ -20,6 +20,7 @@ struct Task {
 
 ///|
 enum ActionOp {
+  Noop
   StatesChange(@respo.RespoUpdateState)
   Increment
   Decrement
@@ -27,15 +28,29 @@ enum ActionOp {
 }
 
 ///|
-impl @respo_node.RespoAction for ActionOp with build_states_action(cursor, a) {
-  ActionOp::StatesChange({ cursor, data: a.map(ToJson::to_json) })
+pub impl Default for ActionOp with default() -> ActionOp {
+  Noop
+}
+
+///|
+impl @respo_node.RespoAction for ActionOp with build_states_action(cursor, a, j) {
+  StatesChange({
+    cursor,
+    data: if a is Some(a) {
+      Some(@dom_ffi.js_obscure_to_v(a))
+    } else {
+      None
+    },
+    backup: j,
+  })
 }
 
 ///|
 impl Show for ActionOp with output(self, logger) -> Unit {
   let s = match self {
-    StatesChange(states) =>
-      "StatesChange(\{states.cursor}  \{states.data.to_json()})"
+    Noop => "Noop"
+    StatesChange(state) =>
+      "StatesChange(\{state.cursor} \{state.backup.to_json()})"
     // Intent(_intent) => "Intent(...)"
     Increment => "Increment"
     Decrement => "Decrement"
@@ -49,7 +64,8 @@ fn get_states(self : Store) -> @respo.RespoStatesTree {
   self.states
 }
 
-///| TODO mutation might break memoization in future
+///|
+/// TODO mutation might break memoization in future
 fn update(self : Store, op : ActionOp) -> Unit {
   match op {
     Increment => self.counted += 1