diff --git a/bg/dynamic_bg/dynamic_bg.gd b/bg/dynamic_bg/dynamic_bg.gd
index 3764568..589e0ff 100644
--- a/bg/dynamic_bg/dynamic_bg.gd
+++ b/bg/dynamic_bg/dynamic_bg.gd
@@ -43,11 +43,6 @@ func _ready():
 		x_offset += $Timer.wait_time * VELOCITY.x
 		x_offset -= int(x_offset / W_STEP) * W_STEP
 		y_offset += $Timer.wait_time * VELOCITY.y
-		print(y_offset)
-
-# Called every frame. 'delta' is the elapsed time since the previous frame.
-func _process(delta):
-	pass
 
 
 func _on_timer_timeout():
diff --git a/bg/dynamic_bg/dynamic_bg_pattern/dynamic_bg_pattern.gd b/bg/dynamic_bg/dynamic_bg_pattern/dynamic_bg_pattern.gd
index 6e37fa4..41df790 100644
--- a/bg/dynamic_bg/dynamic_bg_pattern/dynamic_bg_pattern.gd
+++ b/bg/dynamic_bg/dynamic_bg_pattern/dynamic_bg_pattern.gd
@@ -18,5 +18,10 @@ func _process(delta):
 		queue_free()
 
 func _on_victory_change(v: bool):
-	$Word1.set_victory(v)
-	$Word2.set_victory(v)
+	if v:
+		$Word1.set_color(ImageLib.PALETTE["golden"])
+		$Word2.set_color(ImageLib.PALETTE["golden"])
+	else:
+		$Word1.set_color(ImageLib.PALETTE["default"])
+		$Word2.set_color(ImageLib.PALETTE["default"])
+
diff --git a/levels/base_level/base_level.gd b/levels/base_level/base_level.gd
index 65e9966..4efc086 100644
--- a/levels/base_level/base_level.gd
+++ b/levels/base_level/base_level.gd
@@ -1,11 +1,17 @@
 extends Node
 
 
-const Block := preload("res://objects/block/block.tscn")
-const CardBase := preload("res://objects/card_base/card_base.tscn")
-const LevelMenu := preload("res://levels/chapter_menu/level_menu/level_menu.tscn")
-const TableCloth := preload("res://objects/table_cloth/table_cloth.tscn")
-const BaseLevel := preload("res://levels/base_level/base_level.tscn")
+class_name BaseLevel
+
+# FIXME
+# 由于 Godot preload 容易出错，此处改为 load
+var BlockScn = load("res://objects/block/block.tscn")
+var CardBaseScn = load("res://objects/card_base/card_base.tscn")
+var LevelMenuScn = load("res://levels/chapter_menu/level_menu/level_menu.tscn")
+var TableClothScn = load("res://objects/table_cloth/table_cloth.tscn")
+var BaseLevelScn = load("res://levels/base_level/base_level.tscn")
+
+
 const HEIGHT := 1080 / 4
 const WIDTH := 1920 / 4
 const SEP := 28
@@ -21,14 +27,15 @@ const I_NUMBER = ["I","II","III","VI","V"]
 
 const DATA := [
 	[
-		["=P", "P {} {}", "= P"],
-		["P", "P [] {}", "= P P"],
-		["=D", "D {} {}", "= D P"],
-		["Reverse", "{} {} []", "d d = P P D D"]
+		["=P", "P [] []", "= P"],
+		["Make a Smile", "P {} {}", "= P P"],
+		["=D", "[] {} {}", "P = D D"],
+		["Reversed", "{} [] []", "D D = d d"],
+		["Watch Out the Direction", "[] {} {}", "d d = R R b b"],
 	],
 	[
-		["False", "[] [] 0 {} {}", "= + P P"],
-		["True", "[] {} {} [] 1", "= + P 1"],
+		["0+0=0, 1+0=1", "[] [] {} {} d", "= + 0 d"],
+		["1+1=1", "[] [] {} {} 1", "= + d 1"],
 		["Swap", "Q + [] = {} + []", "P P P P Q Q Q Q"],
 		["Always True", "1 [] {} = {} [] []", "1++PPdd"],
 		["Make Me Laugh", "1 {} {} = []", "XDD"],
@@ -83,7 +90,7 @@ func init(_chap_id: int, _lvl_id: int) -> void:
 	question = question.replace("{}", "_")
 		
 	
-	var table_cloth = TableCloth.instantiate()
+	var table_cloth = TableClothScn.instantiate()
 	var sep := SEP
 	
 	if len(question) >= 16:
@@ -103,7 +110,7 @@ func init(_chap_id: int, _lvl_id: int) -> void:
 	for i in range(len(question)):
 		var ch = question[i]
 		
-		var new_block := Block.instantiate()
+		var new_block = BlockScn.instantiate()
 
 		new_block.quest_pos = i
 		if ch != "." and ch != "_":
@@ -123,12 +130,12 @@ func init(_chap_id: int, _lvl_id: int) -> void:
 		$Blocks.add_child(new_block)
 	
 	expr = question
-	print(expr)
+	# print(expr)
 	
 	
 	pos = WIDTH / 2 - CARDS_SEP * len(choices) / 2 + 16
 	for ch in choices:
-		var new_card_base := CardBase.instantiate()
+		var new_card_base = CardBaseScn.instantiate()
 
 		new_card_base.set_word(ch)
 		
@@ -151,7 +158,7 @@ func _process(_delta):
 func stage_clear() -> void:
 	$SFXs/LevelClear.play()
 	for card_base: CardBase in $CardBases.get_children():
-		card_base.call("set_victory")
+		card_base.set_victory()
 		
 	$HUDs/TableCloth/GoldenCloth.set_visible(true)
 	$HUDs/NextLevelButton.start_fade()
@@ -161,17 +168,17 @@ func _on_card_put() -> void:
 	var block_array = []
 	for block : Block in $Blocks.get_children():
 		if not block.occupied:
-			print(block.quest_pos, " is not occupied")
+			# print(block.quest_pos, " is not occupied")
 			return
 		expr[block.quest_pos] = block.occupied_word
 		block_array.append(block)
 		
-	prints("# expr: ", expr)
+	# prints("# expr: ", expr)
 	
 	if expr.count("_") == 0:
-		var info = $Calculator.check(expr, req_pos)
-		prints("expr:", expr)
-		prints("info:", info)
+		var info = ExprValidator.check(expr, req_pos)
+		# prints("expr:", expr)
+		# prints("info:", info)
 		
 		if info[0] != "OK":
 			$SFXs/WrongAnswer.play()
@@ -179,25 +186,25 @@ func _on_card_put() -> void:
 		if info[0] == "INVALID":
 			for block: Block in $Blocks.get_children():
 				if block.quest_pos in info[1]:
-					block.call("shake")
+					block.shake(false)
 		elif info[0] == "SMILE_UNSATISFIED":
 			for block: Block in $Blocks.get_children():
-				if block.quest_pos == info[1]:
-					block.call("shake")
+				if block.quest_pos in info[1]:
+					block.shake(true)
 		elif info[0] == "NOT_ALWAYS_TRUE":
 			for block: Block in $Blocks.get_children():
-				block.call("shake")
+				block.shake(false)
 		else:
 			# victory
 			get_tree().current_scene.set_victory(true)
 			stage_clear()
-			print(block_array)
+			# print(block_array)
 			for i in range(len(block_array)):
 				if i != 0:
-					if $Calculator.is_smile(expr[i-1]+expr[i]):
-						print(expr[i-1]+expr[i])
-						block_array[i-1].set_victory(true)
-						block_array[i].set_victory(true)
+					if ExprValidator.is_smile(expr[i-1]+expr[i]):
+						# print(expr[i-1]+expr[i])
+						block_array[i-1].set_color(ImageLib.PALETTE["golden"])
+						block_array[i].set_color(ImageLib.PALETTE["golden"])
 
 func _input(event: InputEvent):
 	if event is InputEventKey:
@@ -212,24 +219,24 @@ func _exit_tree():
 
 
 func _on_back_button_pressed():
-	var level_menu = LevelMenu.instantiate()
+	var level_menu = LevelMenuScn.instantiate()
 	level_menu.init(chap_id, -1)
 	get_tree().root.add_child(level_menu)
 	queue_free()
 
 func _on_next_level_button_pressed():
 	if lvl_id == len(DATA[chap_id]) - 1:
-		var level_menu := LevelMenu.instantiate()
+		var level_menu = LevelMenuScn.instantiate()
 		level_menu.init(chap_id + 1, -1)
 		get_tree().root.add_child(level_menu)
 	else:
-		var base_level := BaseLevel.instantiate()
+		var base_level = BaseLevelScn.instantiate()
 		base_level.init(chap_id, lvl_id + 1)
 		get_tree().root.add_child(base_level)
 	queue_free()
 	
 func _on_replay_button_pressed():
-	var new_level = BaseLevel.instantiate()
+	var new_level = BaseLevelScn.instantiate()
 	new_level.init(chap_id, lvl_id)
 	get_tree().root.add_child(new_level)
 	queue_free()
diff --git a/levels/base_level/base_level.tscn b/levels/base_level/base_level.tscn
index 36848e6..7e8de92 100644
--- a/levels/base_level/base_level.tscn
+++ b/levels/base_level/base_level.tscn
@@ -1,7 +1,6 @@
-[gd_scene load_steps=16 format=3 uid="uid://cother2aiigge"]
+[gd_scene load_steps=15 format=3 uid="uid://cother2aiigge"]
 
 [ext_resource type="Script" path="res://levels/base_level/base_level.gd" id="1_diojb"]
-[ext_resource type="PackedScene" uid="uid://xom5kpqs1rue" path="res://objects/calculator/calculator.tscn" id="1_tpuy7"]
 [ext_resource type="PackedScene" uid="uid://bepyyenjtc0p3" path="res://levels/chapter_menu/level_menu/level_button/level_button.tscn" id="2_0egdl"]
 [ext_resource type="PackedScene" uid="uid://d1mp3ld6wsrwo" path="res://levels/base_level/next_level_button/next_level_button.tscn" id="2_0363i"]
 [ext_resource type="Texture2D" uid="uid://bxda1ilvqwc6f" path="res://objects/styled_button/return1.png" id="3_4xtpo"]
@@ -82,8 +81,6 @@ sprite_frames = SubResource("SpriteFrames_5hm0m")
 animation = &"replay"
 centered = false
 
-[node name="Calculator" parent="." instance=ExtResource("1_tpuy7")]
-
 [node name="Cards" type="Node" parent="."]
 
 [node name="Blocks" type="Node" parent="."]
diff --git a/levels/base_level/next_level_button/next_level_button.gd b/levels/base_level/next_level_button/next_level_button.gd
index 52b0ec9..8b058e6 100644
--- a/levels/base_level/next_level_button/next_level_button.gd
+++ b/levels/base_level/next_level_button/next_level_button.gd
@@ -16,7 +16,6 @@ func _ready():
 	position = Vector2(WIDTH / 2 - 20, HEIGHT + 80)
 	$Word.set_word(">")
 
-# Called every frame. 'delta' is the elapsed time since the previous frame.
-func _process(delta):
+func _process(_delta):
 	if fade_flag:
 		position.y = HEIGHT + 50    - 120 * (1 - pow($FadeTimer.time_left / $FadeTimer.wait_time, 1.5))
diff --git a/levels/chapter_menu/chapter_menu.gd b/levels/chapter_menu/chapter_menu.gd
index 7b0e7cc..a9bb8af 100644
--- a/levels/chapter_menu/chapter_menu.gd
+++ b/levels/chapter_menu/chapter_menu.gd
@@ -1,10 +1,10 @@
 extends Node2D
 
+class_name ChapterMenu
 
-
-const BaseLevel := preload("res://levels/base_level/base_level.tscn")
-const LevelButton := preload("res://levels/chapter_menu/level_menu/level_button/level_button.tscn")
-const LevelMenu := preload("res://levels/chapter_menu/level_menu/level_menu.tscn")
+const BaseLevelScn := preload("res://levels/base_level/base_level.tscn")
+const LevelButtonScn := preload("res://levels/chapter_menu/level_menu/level_button/level_button.tscn")
+const LevelMenuScn := preload("res://levels/chapter_menu/level_menu/level_menu.tscn")
 
 # Called when the node enters the scene tree for the first time.
 
@@ -13,32 +13,28 @@ const button_width : int = 50
 const button_heigth : int = 50
 
 func init() -> void:
-	var chap_num : int = len(BaseLevel.instantiate().DATA)
-	for chapter_id in range(0, chap_num):
-		# print(chapter_id)
-		var level_num : int = len(BaseLevel.instantiate().DATA[chapter_id])
-		var button = LevelButton.instantiate();
-		var x : int = button_width * (chapter_id % 9) + 60
-		var y : int = button_heigth * (chapter_id / 9) + 100
-		button.init(chapter_id, level_num, Vector2(x, y), 0)
+	var chap_num : int = len(BaseLevelScn.instantiate().DATA)
+	for lvl_id in range(0, chap_num):
+		# print(lvl_id)
+		var level_num : int = len(BaseLevelScn.instantiate().DATA[lvl_id])
+		var button = LevelButtonScn.instantiate();
+		var x : int = button_width * (lvl_id % 9) + 60
+		var y : int = button_heigth * (lvl_id / 9) + 100
+		button.init(lvl_id, level_num, Vector2(x, y), 0)
 		button.enter_chapter.connect(_is_choose_chapter)
 		add_child(button)
 	
 
 func _ready():
-	print("ready")
+	# print("ready")
 	init()
-	#print(BaseLevel.instantiate().DATA[chapter_id])
+	#print(BaseLevelScn.instantiate().DATA[chapter_id])
 	# print(chapter_num)
 
 
-# Called every frame. 'delta' is the elapsed time since the previous frame.
-func _process(delta):
-	pass
-
-func _is_choose_chapter(chapter_id : int, level_num : int):
-	var level_menu = LevelMenu.instantiate()
-	level_menu.init(chapter_id, level_num)
+func _is_choose_chapter(chap_id : int, level_num : int):
+	var level_menu = LevelMenuScn.instantiate()
+	level_menu.init(chap_id, level_num)
 	# print("here ready to change scene to ", chapter_id)
 	get_tree().root.add_child(level_menu)
 	queue_free()
diff --git a/levels/chapter_menu/level_menu/level_button/level_button.gd b/levels/chapter_menu/level_menu/level_button/level_button.gd
index f6b5023..0a1b504 100644
--- a/levels/chapter_menu/level_menu/level_button/level_button.gd
+++ b/levels/chapter_menu/level_menu/level_button/level_button.gd
@@ -7,15 +7,7 @@ signal enter_chapter(chapter_id:int, level_num : int)
 var lvl_id = 0	# 如果 type = 0 那么 lvl_id 表示的是该章节的关卡数 lvl_num
 var chap_id = 0
 var button_type = 0 # type = 0 表示为选择章节的按钮， type = 1 表示为选择关卡的按钮
-# Called when the node enters the scene tree for the first time.
 
-func _ready():
-	pass # Replace with function body.
-
-
-# Called every frame. 'delta' is the elapsed time since the previous frame.
-func _process(delta):
-	pass
 
 func set_word(value: String) -> void:
 	$Word.set_word(value)
@@ -36,8 +28,8 @@ func init(chapter_id: int, level_id : int, pos : Vector2, type : int) -> void :
 	button_type = type
 
 func _on_pressed():
-	print("choose: ",chap_id,"-",lvl_id)
-	print("! ")
+	# print("choose: ",chap_id,"-",lvl_id)
+	# print("! ")
 	$SFXButtonDown.play()
 	if button_type == 1:
 		enter_level.emit(chap_id, lvl_id)
diff --git a/levels/chapter_menu/level_menu/level_button/level_button.tscn b/levels/chapter_menu/level_menu/level_button/level_button.tscn
index 57ad4cf..ccd244e 100644
--- a/levels/chapter_menu/level_menu/level_button/level_button.tscn
+++ b/levels/chapter_menu/level_menu/level_button/level_button.tscn
@@ -12,3 +12,4 @@ script = ExtResource("1_wwqfn")
 [node name="Word" parent="." index="0" instance=ExtResource("3_js2i2")]
 position = Vector2(19, 19)
 scale = Vector2(1.5, 1.5)
+text_id = 0
diff --git a/levels/chapter_menu/level_menu/level_menu.gd b/levels/chapter_menu/level_menu/level_menu.gd
index aefa87c..c6c9bbc 100644
--- a/levels/chapter_menu/level_menu/level_menu.gd
+++ b/levels/chapter_menu/level_menu/level_menu.gd
@@ -1,14 +1,14 @@
 extends Node2D
 
-
+class_name LevelMenu
 
 const CHAP_NAMES = ["=P", "Add and Multiply", "()", "Equal?", "<>"]
 
 const I_NUMBER = ["I","II","III","VI","V"]
 
-const LevelButton := preload("res://levels/chapter_menu/level_menu/level_button/level_button.tscn")
-const BaseLevel := preload("res://levels/base_level/base_level.tscn")
-const Credits := preload("res://objects/credits/credits.tscn")
+const LevelButtonScn := preload("res://levels/chapter_menu/level_menu/level_button/level_button.tscn")
+const BaseLevelScn := preload("res://levels/base_level/base_level.tscn")
+const CreditsScn := preload("res://objects/credits/credits.tscn")
 
 # Called when the node enters the scene tree for the first time.
 
@@ -19,21 +19,21 @@ const button_heigth : int = 50
 func init(chap_id : int, lvl_num : int) -> void:
 	#print("init?")
 	
-	if chap_id == len(BaseLevel.instantiate().DATA):
-		add_child(Credits.instantiate())
+	if chap_id == len(BaseLevelScn.instantiate().DATA):
+		add_child(CreditsScn.instantiate())
 		$Title.set_text("")
 		return
 		
 	
 	if lvl_num == -1:
-		lvl_num = len(BaseLevel.instantiate().DATA[chap_id])
+		lvl_num = len(BaseLevelScn.instantiate().DATA[chap_id])
 	
 	$Title.set_text("Ch." + I_NUMBER[chap_id] + "  " + CHAP_NAMES[chap_id])
 	
 	chapter_id = chap_id
 	for level_id in range(0, lvl_num):
 		#print(level_id)
-		var button = LevelButton.instantiate();
+		var button = LevelButtonScn.instantiate();
 		var x : int = button_width * (level_id % 7) + 60
 		var y : int = button_heigth * (level_id / 7) + 100
 		button.init(chapter_id, level_id, Vector2(x, y), 1)
@@ -48,12 +48,9 @@ func _ready():
 	#print("why not?")
 	pass
 
-# Called every frame. 'delta' is the elapsed time since the previous frame.
-func _process(delta):
-	pass
 
 func _on_button_enter_level(chap_id: int, lvl_id: int) -> void:
-	var base_level := BaseLevel.instantiate()
+	var base_level := BaseLevelScn.instantiate()
 	
 	# print(chap_id, lvl_id)
 	
@@ -67,8 +64,8 @@ func _input(event: InputEvent):
 			_on_back_button_pressed()
 
 func _on_back_button_pressed():
-	var ChapterMenu = load("res://levels/chapter_menu/chapter_menu.tscn")
-	var chapter_menu = ChapterMenu.instantiate()
+	var ChapterMenuScn = load("res://levels/chapter_menu/chapter_menu.tscn")
+	var chapter_menu = ChapterMenuScn.instantiate()
 	
 	chapter_menu.init()
 	get_tree().root.add_child(chapter_menu)
diff --git a/objects/block/block.gd b/objects/block/block.gd
index 997abc0..97ac109 100644
--- a/objects/block/block.gd
+++ b/objects/block/block.gd
@@ -3,32 +3,31 @@ extends Area2D
 class_name Block
 
 
-const SHAKE_AMOUNT := 4
+const SHAKE_AMOUNT := 3.0 ## 振动时的振幅（单位为像素）。
 
 
-var occupied := false
-var occupied_word: String
-var occupied_card: Card
+var occupied := false ## 当 Block 上有 Card 或 Block 字符固定时，occupied 为 true。
+var occupied_word := "_" ## Block 上的字符，若没有字符则为 _ 。
+var occupied_card: Card = null
+
+var quest_pos := -1 ## 在表达式中对应字符位置的下标。
+var is_shaking := false ## 是否正在振动。
 
-var quest_pos := -1
-var is_shaking := false
 
 
 func _on_area_entered(area: Card):
-	#prints("Entered", self, name)
 	if not occupied:
 		area.on_card_entered(self)
 
 func _on_area_exited(area: Card):
-	#prints("Exited", self, name)
 	if not occupied:
 		area.on_card_exited()
 
-func set_word(e: String) -> void:
-	$Word.set_word(e)
-	if e != "_" and e != ".":
+func set_word(value: String) -> void:
+	$Word.set_word(value)
+	if value != "_" and value != ".":
 		occupied = true
-		occupied_word = e
+		occupied_word = value
 	else:
 		occupied = false
 		occupied_word = "_"
@@ -63,15 +62,33 @@ func _process(_delta):
 	$Word.position.x = offset 
 
 
-func shake():
+## 开始震动。
+## is_frame_red 表示是否将框改为红色。
+func shake(is_frame_red: bool) -> void: 
+	# 开启震动
 	$ShakeTimer.start()
 	is_shaking = true
-
-func _on_shake_timer_timeout():
+	
+	# 使附着的卡牌也震动
+	if occupied_card != null:
+		occupied_card.shake(not is_frame_red, SHAKE_AMOUNT, $ShakeTimer.wait_time) # 若框不红，则里面的字要红
+	elif not is_frame_red:
+		$Word.set_color(ImageLib.PALETTE["red"])
+	
+	if is_frame_red:
+		$GoalFrameSprite.animation = "red"
+	
+func _on_shake_timer_timeout() -> void:
 	is_shaking = false
+	$GoalFrameSprite.animation = "default"
+	$Word.set_color(ImageLib.PALETTE["default"])
 	
-func set_victory(v: bool):
-	if occupied and occupied_card:
+func set_victory(v: bool) -> void:
+	if v and occupied_card != null:
 		occupied_card.set_victory(v)
+
+func set_color(value: Color) -> void:
+	if occupied_card != null:
+		occupied_card.set_color(value)
 	else:
-		$Word.set_victory(v)
+		$Word.set_color(value)	
diff --git a/objects/block/block.tscn b/objects/block/block.tscn
index 75f677a..89f6f66 100644
--- a/objects/block/block.tscn
+++ b/objects/block/block.tscn
@@ -1,13 +1,33 @@
-[gd_scene load_steps=6 format=3 uid="uid://ckjmjwywh78fe"]
+[gd_scene load_steps=8 format=3 uid="uid://ckjmjwywh78fe"]
 
 [ext_resource type="Script" path="res://objects/block/block.gd" id="1_11h57"]
 [ext_resource type="PackedScene" uid="uid://cvx7wowcbfo0r" path="res://objects/word/word.tscn" id="2_pjs40"]
 [ext_resource type="Texture2D" uid="uid://dvj7bjepxeks0" path="res://objects/block/pit.png" id="3_ye3hk"]
-[ext_resource type="Texture2D" uid="uid://cb71r50jw2a3i" path="res://objects/block/goal_frame2.png" id="4_v6rgm"]
+[ext_resource type="Texture2D" uid="uid://cb71r50jw2a3i" path="res://objects/block/goal_frame.png" id="4_yvtjk"]
+[ext_resource type="Texture2D" uid="uid://cvv532ui6p5gg" path="res://objects/block/goal_frame_red.png" id="5_et5vw"]
 
 [sub_resource type="RectangleShape2D" id="RectangleShape2D_3if4e"]
 size = Vector2(16, 16)
 
+[sub_resource type="SpriteFrames" id="SpriteFrames_3dme2"]
+animations = [{
+"frames": [{
+"duration": 1.0,
+"texture": ExtResource("4_yvtjk")
+}],
+"loop": true,
+"name": &"default",
+"speed": 5.0
+}, {
+"frames": [{
+"duration": 1.0,
+"texture": ExtResource("5_et5vw")
+}],
+"loop": true,
+"name": &"red",
+"speed": 5.0
+}]
+
 [node name="Block" type="Area2D"]
 script = ExtResource("1_11h57")
 
@@ -22,11 +42,11 @@ debug_color = Color(0.968627, 0, 0.470588, 0.419608)
 z_index = -1
 texture = ExtResource("3_ye3hk")
 
-[node name="GoalFrameSprite" type="Sprite2D" parent="."]
-texture = ExtResource("4_v6rgm")
-
 [node name="ShakeTimer" type="Timer" parent="."]
-wait_time = 0.1
+wait_time = 0.2
+
+[node name="GoalFrameSprite" type="AnimatedSprite2D" parent="."]
+sprite_frames = SubResource("SpriteFrames_3dme2")
 
 [connection signal="area_entered" from="." to="." method="_on_area_entered"]
 [connection signal="area_exited" from="." to="." method="_on_area_exited"]
diff --git a/objects/block/goal_frame2.png b/objects/block/goal_frame.png
similarity index 100%
rename from objects/block/goal_frame2.png
rename to objects/block/goal_frame.png
diff --git a/objects/block/goal_frame2.png.import b/objects/block/goal_frame.png.import
similarity index 71%
rename from objects/block/goal_frame2.png.import
rename to objects/block/goal_frame.png.import
index bf7c4a2..88950b4 100644
--- a/objects/block/goal_frame2.png.import
+++ b/objects/block/goal_frame.png.import
@@ -3,15 +3,15 @@
 importer="texture"
 type="CompressedTexture2D"
 uid="uid://cb71r50jw2a3i"
-path="res://.godot/imported/goal_frame2.png-4f7b6acdd1bc6edd73dd7776acb6603f.ctex"
+path="res://.godot/imported/goal_frame.png-a7b1f754b088dcafe5e3aa2d70e0feb1.ctex"
 metadata={
 "vram_texture": false
 }
 
 [deps]
 
-source_file="res://objects/block/goal_frame2.png"
-dest_files=["res://.godot/imported/goal_frame2.png-4f7b6acdd1bc6edd73dd7776acb6603f.ctex"]
+source_file="res://objects/block/goal_frame.png"
+dest_files=["res://.godot/imported/goal_frame.png-a7b1f754b088dcafe5e3aa2d70e0feb1.ctex"]
 
 [params]
 
diff --git a/objects/block/goal_frame_red.png b/objects/block/goal_frame_red.png
new file mode 100644
index 0000000..f4e169c
Binary files /dev/null and b/objects/block/goal_frame_red.png differ
diff --git a/objects/card_base/card_base_highlighted.png.import b/objects/block/goal_frame_red.png.import
similarity index 65%
rename from objects/card_base/card_base_highlighted.png.import
rename to objects/block/goal_frame_red.png.import
index 5c5565a..7fca3a1 100644
--- a/objects/card_base/card_base_highlighted.png.import
+++ b/objects/block/goal_frame_red.png.import
@@ -2,16 +2,16 @@
 
 importer="texture"
 type="CompressedTexture2D"
-uid="uid://cs7vfmsrhpomj"
-path="res://.godot/imported/card_base_highlighted.png-50d4af98046c8a87d73d61ca6664f89e.ctex"
+uid="uid://cvv532ui6p5gg"
+path="res://.godot/imported/goal_frame_red.png-33a617e8ebea76a5c0e24baba0e7afcc.ctex"
 metadata={
 "vram_texture": false
 }
 
 [deps]
 
-source_file="res://objects/card_base/card_base_highlighted.png"
-dest_files=["res://.godot/imported/card_base_highlighted.png-50d4af98046c8a87d73d61ca6664f89e.ctex"]
+source_file="res://objects/block/goal_frame_red.png"
+dest_files=["res://.godot/imported/goal_frame_red.png-33a617e8ebea76a5c0e24baba0e7afcc.ctex"]
 
 [params]
 
diff --git a/objects/calculator/calculator.tscn b/objects/calculator/calculator.tscn
deleted file mode 100644
index 3b2d191..0000000
--- a/objects/calculator/calculator.tscn
+++ /dev/null
@@ -1,6 +0,0 @@
-[gd_scene load_steps=2 format=3 uid="uid://xom5kpqs1rue"]
-
-[ext_resource type="Script" path="res://objects/calculator/calculator.gd" id="1_b65po"]
-
-[node name="Calculator" type="Node"]
-script = ExtResource("1_b65po")
diff --git a/objects/card/card.gd b/objects/card/card.gd
index b3676ec..bba1a27 100644
--- a/objects/card/card.gd
+++ b/objects/card/card.gd
@@ -16,11 +16,16 @@ var last_occupied_area: Block
 var is_card_base_entered = 0
 var entered_card_base_global_position: Vector2
 
-var is_victory = false
+var is_victory := false
+
+var shake_amount : float
+var is_shaking := false
+
 
 func _ready():
 	origin_global_position = global_position
 	last_global_position = global_position
+	$HighlightSprite.visible = false
 
 func _on_mouse_release():
 	#prints(entered_area.name, is_card_entered, entered_area.occupied)
@@ -69,7 +74,7 @@ func _on_mouse_pressed():
 	is_card_base_entered = 0
 	
 
-func _input_event(viewport: Object, event: InputEvent, shape_idx: int) -> void:
+func _input_event(_viewport: Object, event: InputEvent, _shape_idx: int) -> void:
 	#prints(self, event)
 	if not is_victory and event is InputEventMouseButton:
 		if event.is_pressed() and event.button_index == MOUSE_BUTTON_LEFT:
@@ -80,14 +85,21 @@ func _input_event(viewport: Object, event: InputEvent, shape_idx: int) -> void:
 		if event.is_pressed() and event.button_index == MOUSE_BUTTON_RIGHT:
 			reset_position()
 
-func _process(delta: float) -> void:
-	#prints(name, global_position)
+func _process(_delta: float) -> void:
 	if not have_deal_on_mouse_release and not Input.is_mouse_button_pressed(MOUSE_BUTTON_LEFT):
 		_on_mouse_release()
 	if is_dragging:
 		have_deal_on_mouse_release = false
 		global_position = get_global_mouse_position().round()
 		Input.set_default_cursor_shape(Input.CURSOR_DRAG)
+		
+	var offset := 0
+	if is_shaking:
+		var progress = $ShakeTimer.time_left / $ShakeTimer.wait_time * 2 * PI
+		offset = int(sin(progress) * shake_amount)
+	$CardBackSprite.position.x = offset
+	$HighlightSprite.position.x = offset
+	$Word.position.x = offset 
 
 func on_card_entered(area: Block) -> void:
 	is_card_entered += 1
@@ -106,22 +118,53 @@ func on_card_base_exited() -> void:
 	is_card_base_entered -= 1
 	#print(is_card_entered)
 
-func set_word(e: String) -> void:
-	$Word.set_word(e)
+func set_word(value: String) -> void:
+	$Word.set_word(value)
+	var card_type := "card-%s" % ExprValidator.get_char_type_as_str(get_word()).to_lower()
+	if ImageLib.PALETTE.has(card_type):
+		ImageLib.update_animation(
+			$CardBackSprite, 1, 3, 1, "res://objects/card/card%d.png", 
+			ImageLib.PALETTE["lightblue"], ImageLib.PALETTE[card_type]
+		)
+	
 
 func get_word() -> String:
 	return $Word.get_word()
 
 
+func shake(is_letter_red: bool, amount: float, duration: float) -> void:
+	$ShakeTimer.wait_time = duration
+	shake_amount = amount
+
+	# 开启震动
+	$ShakeTimer.start()
+	is_shaking = true
+	
+	
+	if is_letter_red:
+		$Word.set_color(ImageLib.PALETTE["red"])
+	else:
+		$HighlightSprite.visible = false
+
+
 
 
 func _on_mouse_entered():
-	$CardBackSprite.animation = "highlighted"
+	$HighlightSprite.visible = true
 	Input.set_default_cursor_shape(Input.CURSOR_POINTING_HAND)
 
 func _on_mouse_exited():
-	$CardBackSprite.animation = "default"
+	$HighlightSprite.visible = false
 	Input.set_default_cursor_shape(Input.CURSOR_ARROW)
 
+func set_color(value: Color) -> void:
+	$Word.set_color(value)
+
 func set_victory(v: bool):
-	$Word.set_victory(v)
+	if v:
+		$CollisionShape2D.set_deferred("disabled", true)
+
+
+func _on_shake_timer_timeout():
+	is_shaking = false
+	$Word.set_color(ImageLib.PALETTE["default"])
diff --git a/objects/card/card.tscn b/objects/card/card.tscn
index 0c0571d..02533d7 100644
--- a/objects/card/card.tscn
+++ b/objects/card/card.tscn
@@ -5,11 +5,9 @@
 [ext_resource type="Texture2D" uid="uid://cfbqh1k0etr6g" path="res://objects/card/card1.png" id="3_o4f0v"]
 [ext_resource type="Texture2D" uid="uid://c8qjbksyn1bqt" path="res://objects/card/card2.png" id="4_c30j1"]
 [ext_resource type="Texture2D" uid="uid://bevrfq1hhyqwe" path="res://objects/card/card3.png" id="5_w81n3"]
-[ext_resource type="Texture2D" uid="uid://cmcc5xrpkrd0f" path="res://objects/card/card_highlighted.png" id="6_po2i6"]
+[ext_resource type="Texture2D" uid="uid://pmapbo480in1" path="res://objects/card/card_highlight_border.png" id="7_kix4t"]
 [ext_resource type="AudioStream" uid="uid://cj4v8ehypq3sk" path="res://objects/card/put_down.wav" id="7_u4ylf"]
 
-[sub_resource type="RectangleShape2D" id="RectangleShape2D_gu6l6"]
-
 [sub_resource type="SpriteFrames" id="SpriteFrames_fo0r0"]
 animations = [{
 "frames": [{
@@ -25,35 +23,35 @@ animations = [{
 "loop": true,
 "name": &"default",
 "speed": 5.0
-}, {
-"frames": [{
-"duration": 1.0,
-"texture": ExtResource("6_po2i6")
-}],
-"loop": true,
-"name": &"highlighted",
-"speed": 5.0
 }]
 
+[sub_resource type="RectangleShape2D" id="RectangleShape2D_gu6l6"]
+
 [node name="Card" type="Area2D"]
 z_index = 50
 script = ExtResource("1_0bviv")
 
 [node name="Word" parent="." instance=ExtResource("1_ns36n")]
 z_index = 1
-frame_progress = 0.111549
+
+[node name="CardBackSprite" type="AnimatedSprite2D" parent="."]
+sprite_frames = SubResource("SpriteFrames_fo0r0")
+
+[node name="HighlightSprite" type="Sprite2D" parent="."]
+texture = ExtResource("7_kix4t")
 
 [node name="CollisionShape2D" type="CollisionShape2D" parent="."]
 z_index = 15
 shape = SubResource("RectangleShape2D_gu6l6")
 
-[node name="CardBackSprite" type="AnimatedSprite2D" parent="."]
-sprite_frames = SubResource("SpriteFrames_fo0r0")
-autoplay = "default"
-
 [node name="SFXPutDown" type="AudioStreamPlayer" parent="."]
 stream = ExtResource("7_u4ylf")
 volume_db = 13.117
 
+[node name="ShakeTimer" type="Timer" parent="."]
+wait_time = 100.0
+one_shot = true
+
 [connection signal="mouse_entered" from="." to="." method="_on_mouse_entered"]
 [connection signal="mouse_exited" from="." to="." method="_on_mouse_exited"]
+[connection signal="timeout" from="ShakeTimer" to="." method="_on_shake_timer_timeout"]
diff --git a/objects/card/card_highlight_border.png b/objects/card/card_highlight_border.png
new file mode 100644
index 0000000..2f7f195
Binary files /dev/null and b/objects/card/card_highlight_border.png differ
diff --git a/objects/card/card_highlight_border.png.import b/objects/card/card_highlight_border.png.import
new file mode 100644
index 0000000..ba37e56
--- /dev/null
+++ b/objects/card/card_highlight_border.png.import
@@ -0,0 +1,34 @@
+[remap]
+
+importer="texture"
+type="CompressedTexture2D"
+uid="uid://pmapbo480in1"
+path="res://.godot/imported/card_highlight_border.png-c0b130850c2d1dcdc5af25ea7e1dafdc.ctex"
+metadata={
+"vram_texture": false
+}
+
+[deps]
+
+source_file="res://objects/card/card_highlight_border.png"
+dest_files=["res://.godot/imported/card_highlight_border.png-c0b130850c2d1dcdc5af25ea7e1dafdc.ctex"]
+
+[params]
+
+compress/mode=0
+compress/high_quality=false
+compress/lossy_quality=0.7
+compress/hdr_compression=1
+compress/normal_map=0
+compress/channel_pack=0
+mipmaps/generate=false
+mipmaps/limit=-1
+roughness/mode=0
+roughness/src_normal=""
+process/fix_alpha_border=true
+process/premult_alpha=false
+process/normal_map_invert_y=false
+process/hdr_as_srgb=false
+process/hdr_clamp_exposure=false
+process/size_limit=0
+detect_3d/compress_to=1
diff --git a/objects/card/card_highlighted.png b/objects/card/card_highlighted.png
deleted file mode 100644
index 8a2398b..0000000
Binary files a/objects/card/card_highlighted.png and /dev/null differ
diff --git a/objects/card_base/card_base.gd b/objects/card_base/card_base.gd
index 036de2e..24b8580 100644
--- a/objects/card_base/card_base.gd
+++ b/objects/card_base/card_base.gd
@@ -2,7 +2,7 @@ extends Area2D
 
 class_name CardBase
 
-const Card := preload("res://objects/card/card.tscn")
+const CardScn := preload("res://objects/card/card.tscn")
 const FADE_MOVE_AMOUNT := 70
 
 signal card_put
@@ -11,6 +11,9 @@ signal card_put
 var fade_flag := false
 var mouse_on := false
 
+enum { DEFAULT, HIGHLIGHT, DISABLED}
+var available_stat := DEFAULT
+
 
 var card_count = 0
 var new_card_node: Card
@@ -25,11 +28,11 @@ func set_card_count(value):
 	card_count = value
 	if card_count > 0:
 		if mouse_on:
-			$AnimatedSprite2D.animation = "highlighted"
+			available_stat = HIGHLIGHT
 		else:
-			$AnimatedSprite2D.animation = "default"
+			available_stat = DEFAULT
 	else:
-		$AnimatedSprite2D.animation = "disabled"
+		available_stat = DISABLED
 	update_card_count_label()
 
 
@@ -39,7 +42,7 @@ func draw_card():
 	set_card_count(card_count - 1) 
 	$SFXPickUp.play()
 	Input.set_default_cursor_shape(Input.CURSOR_DRAG)
-	new_card_node = Card.instantiate()
+	new_card_node = CardScn.instantiate()
 	new_card_node.set_word($Word.get_word())
 	new_card_node.set_position(position)
 	$Cards.add_child(new_card_node)
@@ -66,13 +69,21 @@ func _on_area_exited(area: Card):
 	if area.get_word() == $Word.get_word():
 		area.on_card_base_exited()
 	
-func _input_event(viewport: Object, event: InputEvent, shape_idx: int) -> void:
+func _input_event(_viewport: Object, event: InputEvent, _shape_idx: int) -> void:
 	if event is InputEventMouseButton:
 		if event.is_pressed() and event.button_index == MOUSE_BUTTON_LEFT:
 			draw_card()
 
 func set_word(e: String) -> void:
 	$Word.set_word(e)
+	
+	var card_type := "card-%s" % ExprValidator.get_char_type_as_str(e).to_lower()
+	if ImageLib.PALETTE.has(card_type):
+		ImageLib.update_animation($CardBaseSprite, 1, 1, 1, "res://objects/card_base/card_base%d.png", 
+								  ImageLib.PALETTE["lightblue"], ImageLib.PALETTE[card_type])
+	
+func get_word() -> String:
+	return $Word.get_word()
 
 func _on_card_put():
 	emit_signal("card_put")
@@ -85,28 +96,33 @@ func set_victory() -> void:
 	$Label.set_visible(false)
 	
 	for card: Card in $Cards.get_children():
-		card.is_victory = true
+		card.set_victory(true)
 
 func reset_all_card_position():
 	for card: Card in $Cards.get_children():
 		card.reset_position()
 
-func _process(delta) -> void:
+func _process(_delta) -> void:
 	if fade_flag:
 		var offset = $FadeTimer.time_left / $FadeTimer.wait_time
 		offset = (1 - pow(offset, 1.5)) * FADE_MOVE_AMOUNT
-		$AnimatedSprite2D.position.y = offset
+		$CardBaseSprite.position.y = offset
+		$HighlightSprite.position.y = offset
+		$DisabledSprite.position.y = offset
 		$Word.position.y = offset
+	
+	$HighlightSprite.visible = (available_stat == HIGHLIGHT)
+	$DisabledSprite.visible = (available_stat == DISABLED)
 
 
 func _on_mouse_entered():
 	mouse_on = true
-	if $AnimatedSprite2D.animation == "default":
-		$AnimatedSprite2D.animation = "highlighted"	
+	if available_stat == DEFAULT:
+		available_stat = HIGHLIGHT
 		Input.set_default_cursor_shape(Input.CURSOR_POINTING_HAND)
 
 func _on_mouse_exited():
 	mouse_on = false
-	if $AnimatedSprite2D.animation == "highlighted":
-		$AnimatedSprite2D.animation = "default"
+	if available_stat == HIGHLIGHT:
+		available_stat = DEFAULT
 		Input.set_default_cursor_shape(Input.CURSOR_ARROW)
diff --git a/objects/card_base/card_base.tscn b/objects/card_base/card_base.tscn
index 1bdbd1b..e02c82e 100644
--- a/objects/card_base/card_base.tscn
+++ b/objects/card_base/card_base.tscn
@@ -5,7 +5,7 @@
 [ext_resource type="FontFile" uid="uid://1000owdyvwfg" path="res://fonts/unifont-15.1.04.otf" id="3_0qykx"]
 [ext_resource type="Texture2D" uid="uid://b5d2rfms7vyfi" path="res://objects/card_base/card_base1.png" id="3_h7i1h"]
 [ext_resource type="Texture2D" uid="uid://bkjbrw1ppac5q" path="res://objects/card_base/card_base_disabled.png" id="4_0unxr"]
-[ext_resource type="Texture2D" uid="uid://cs7vfmsrhpomj" path="res://objects/card_base/card_base_highlighted.png" id="5_tkdj2"]
+[ext_resource type="Texture2D" uid="uid://bkuwo3g8pyuyi" path="res://objects/card_base/card_base_highlight_border.png" id="5_r41oe"]
 [ext_resource type="AudioStream" uid="uid://0sefo32v1jne" path="res://objects/card_base/pick_up.wav" id="7_0c7kt"]
 
 [sub_resource type="RectangleShape2D" id="RectangleShape2D_2cmwb"]
@@ -28,14 +28,6 @@ animations = [{
 "loop": true,
 "name": &"disabled",
 "speed": 5.0
-}, {
-"frames": [{
-"duration": 1.0,
-"texture": ExtResource("5_tkdj2")
-}],
-"loop": true,
-"name": &"highlighted",
-"speed": 5.0
 }]
 
 [node name="CardBase" type="Area2D"]
@@ -45,10 +37,20 @@ script = ExtResource("1_k5qn1")
 shape = SubResource("RectangleShape2D_2cmwb")
 debug_color = Color(0.65098, 0.431373, 0.756863, 0.419608)
 
+[node name="CardBaseSprite" type="AnimatedSprite2D" parent="."]
+sprite_frames = SubResource("SpriteFrames_bhb3x")
+
 [node name="Word" parent="." instance=ExtResource("2_jvsp3")]
-z_index = 1
 frame_progress = 0.953211
 
+[node name="HighlightSprite" type="Sprite2D" parent="."]
+visible = false
+texture = ExtResource("5_r41oe")
+
+[node name="DisabledSprite" type="Sprite2D" parent="."]
+visible = false
+texture = ExtResource("4_0unxr")
+
 [node name="Label" type="Label" parent="."]
 offset_left = -13.0
 offset_top = 17.0
@@ -59,9 +61,6 @@ text = "0"
 horizontal_alignment = 1
 vertical_alignment = 1
 
-[node name="AnimatedSprite2D" type="AnimatedSprite2D" parent="."]
-sprite_frames = SubResource("SpriteFrames_bhb3x")
-
 [node name="Cards" type="Node" parent="."]
 
 [node name="FadeTimer" type="Timer" parent="."]
diff --git a/objects/card_base/card_base_highlight_border.png b/objects/card_base/card_base_highlight_border.png
new file mode 100644
index 0000000..19ad568
Binary files /dev/null and b/objects/card_base/card_base_highlight_border.png differ
diff --git a/objects/card_base/card_base_highlight_border.png.import b/objects/card_base/card_base_highlight_border.png.import
new file mode 100644
index 0000000..5de750e
--- /dev/null
+++ b/objects/card_base/card_base_highlight_border.png.import
@@ -0,0 +1,34 @@
+[remap]
+
+importer="texture"
+type="CompressedTexture2D"
+uid="uid://bkuwo3g8pyuyi"
+path="res://.godot/imported/card_base_highlight_border.png-02641e6f6e23a694917134adadde948a.ctex"
+metadata={
+"vram_texture": false
+}
+
+[deps]
+
+source_file="res://objects/card_base/card_base_highlight_border.png"
+dest_files=["res://.godot/imported/card_base_highlight_border.png-02641e6f6e23a694917134adadde948a.ctex"]
+
+[params]
+
+compress/mode=0
+compress/high_quality=false
+compress/lossy_quality=0.7
+compress/hdr_compression=1
+compress/normal_map=0
+compress/channel_pack=0
+mipmaps/generate=false
+mipmaps/limit=-1
+roughness/mode=0
+roughness/src_normal=""
+process/fix_alpha_border=true
+process/premult_alpha=false
+process/normal_map_invert_y=false
+process/hdr_as_srgb=false
+process/hdr_clamp_exposure=false
+process/size_limit=0
+detect_3d/compress_to=1
diff --git a/objects/card_base/card_base_highlighted.png b/objects/card_base/card_base_highlighted.png
deleted file mode 100644
index 6213968..0000000
Binary files a/objects/card_base/card_base_highlighted.png and /dev/null differ
diff --git a/objects/main_menu/main_menu.gd b/objects/main_menu/main_menu.gd
index d88730c..3102de5 100644
--- a/objects/main_menu/main_menu.gd
+++ b/objects/main_menu/main_menu.gd
@@ -1,7 +1,9 @@
 extends Node2D
 
-const ChapterMenu = preload("res://levels/chapter_menu/chapter_menu.tscn")
-const BaseLevel := preload("res://levels/base_level/base_level.tscn")
+class_name MainMenu
+
+const ChapterMenuScn := preload("res://levels/chapter_menu/chapter_menu.tscn")
+const BaseLevelScn := preload("res://levels/base_level/base_level.tscn")
 
 signal enter_level()
 
@@ -10,7 +12,7 @@ func _ready():
 
 
 func _on_start_button_pressed():
-	var base_level := BaseLevel.instantiate()
+	var base_level := BaseLevelScn.instantiate()
 	
 	# print(chap_id, lvl_id)
 	
@@ -18,7 +20,7 @@ func _on_start_button_pressed():
 	get_tree().root.add_child(base_level)
 	enter_level.emit()
 	queue_free()
-	#get_tree().root.add_child(ChapterMenu.instantiate())
+	#get_tree().root.add_child(ChapterMenuScn.instantiate())
 	#queue_free()
 
 
diff --git a/objects/main_menu/start_button.gd b/objects/main_menu/start_button.gd
index f430e49..02e8a60 100644
--- a/objects/main_menu/start_button.gd
+++ b/objects/main_menu/start_button.gd
@@ -1,11 +1,5 @@
 extends Button
 
 
-# Called when the node enters the scene tree for the first time.
 func _ready():
 	$AnimatedSprite2D.play()
-
-
-# Called every frame. 'delta' is the elapsed time since the previous frame.
-func _process(delta):
-	pass
diff --git a/objects/word/word.gd b/objects/word/word.gd
index 77fba69..74ba764 100644
--- a/objects/word/word.gd
+++ b/objects/word/word.gd
@@ -2,7 +2,7 @@ extends AnimatedSprite2D
 
 
 @export var text_id := 1
-@export var is_victory = false
+@export var color := Color.BLACK
 
 
 const STEP := 30
@@ -18,60 +18,47 @@ const LETTER_NAME = ["_", "=", "P", "b", "D",
 func get_letter_id(letter: String) -> int:
 	for i in range(len(LETTER_NAME)):
 		if LETTER_NAME[i] == letter:
-			return i + 1
+			return i
 	assert(false, "Letter " + letter + " not found")
 	return -1
 	
 
 ## 内建，不要用。
 func set_text_id(value: int) -> void:
+	assert(value >= 0, "text id < 0")
 	text_id = value
-	
-	assert(value > 0, "text id <= 0")
-	
-	var animation_id = str(text_id) + str(is_victory)
-	if not sprite_frames.has_animation(animation_id):
-		sprite_frames.add_animation(animation_id)
-		for i in range(3):
-			sprite_frames.add_frame(animation_id, load_image(i * STEP + text_id, is_victory))
-	animation = animation_id
+	update_animation()
+
+func update_animation() -> void:
+	ImageLib.update_animation(self, text_id + 1, 3, STEP, "res://objects/word/sprites/sprite%d.png", Color.BLACK, color)
 	
 	
 
 ## 更改字母为 text。
 func set_word(text: String) -> void:
 	if text == "_" or text == ".":
-		set_text_id(1)
+		set_text_id(0)
 	else:
 		set_text_id(get_letter_id(text))
 
 ## 获得当前字母。
 func get_word() -> String:
-	return LETTER_NAME[text_id - 1]
+	return LETTER_NAME[text_id]
 
 
 func _ready():
-	set_text_id(text_id)
+	update_animation()
 
+func set_color(value: Color) -> void:
+	color = value
+	update_animation()
 
-func _process(delta):
-	if animation == "default":
-		set_text_id(text_id)
-		
-func set_victory(v: bool):
-	if v != is_victory:
-		is_victory = v
-		set_text_id(text_id)
-		
-func load_image(h: int, is_victory: bool):
-	var image := load("res://objects/word/sprites/sprite" + str(h) + ".png")
-	if is_victory:
-		var new_texture = image.get_image()
-		for x in range(new_texture.get_width()):
-			for y in range(new_texture.get_height()):
-				var color = new_texture.get_pixel(x, y)
-				if color == Color(0, 0, 0, 1):  # 如果像素是黑色
-					new_texture.set_pixel(x, y, Color.hex(0xf5df4dff))  # 将其改为金黄色
-		return ImageTexture.create_from_image(new_texture)
-		
-	return image
+## 设置是否为关卡通过状态。
+## 已弃用，请使用 set_color 或 set_color_from_name 代替。
+## @deprecated
+func set_victory(v: bool) -> void:
+	push_warning("void set_victory(v: bool) is deprecated.")
+	if v:
+		set_color(ImageLib.PALETTE["golden"])
+	else:
+		set_color(ImageLib.PALETTE["default"])
diff --git a/objects/word/word.tscn b/objects/word/word.tscn
index 2a8189a..3678ecc 100644
--- a/objects/word/word.tscn
+++ b/objects/word/word.tscn
@@ -1,33 +1,19 @@
-[gd_scene load_steps=6 format=3 uid="uid://cvx7wowcbfo0r"]
+[gd_scene load_steps=4 format=3 uid="uid://cvx7wowcbfo0r"]
 
 [ext_resource type="Texture2D" uid="uid://cyyu6tsje4x72" path="res://objects/word/sprites/sprite3.png" id="1_ariam"]
 [ext_resource type="Script" path="res://objects/word/word.gd" id="1_lkxlh"]
-[ext_resource type="Texture2D" uid="uid://bqtqgiv5etyny" path="res://objects/word/sprites/sprite28.png" id="2_l4ops"]
-[ext_resource type="Texture2D" uid="uid://dua7hylyf4ws6" path="res://objects/word/sprites/sprite53.png" id="3_2kshj"]
 
 [sub_resource type="SpriteFrames" id="SpriteFrames_3n85j"]
 animations = [{
 "frames": [{
 "duration": 1.0,
 "texture": ExtResource("1_ariam")
-}, {
-"duration": 1.0,
-"texture": ExtResource("2_l4ops")
-}, {
-"duration": 1.0,
-"texture": ExtResource("3_2kshj")
 }],
 "loop": true,
 "name": &"default",
-"speed": 3.0
-}, {
-"frames": [],
-"loop": true,
-"name": &"new_animation",
 "speed": 5.0
 }]
 
 [node name="Word" type="AnimatedSprite2D"]
 sprite_frames = SubResource("SpriteFrames_3n85j")
-autoplay = "default"
 script = ExtResource("1_lkxlh")
diff --git a/project.godot b/project.godot
index 6c26cb8..0fb29d5 100644
--- a/project.godot
+++ b/project.godot
@@ -16,6 +16,10 @@ config/features=PackedStringArray("4.2", "Forward Plus")
 boot_splash/bg_color=Color(0.196078, 0.184314, 0.301961, 1)
 config/icon="res://=P3.png"
 
+[debug]
+
+gdscript/warnings/integer_division=0
+
 [display]
 
 window/size/viewport_width=1920
diff --git a/objects/calculator/calculator.gd b/scripts/expr_validator.gd
similarity index 69%
rename from objects/calculator/calculator.gd
rename to scripts/expr_validator.gd
index 9aa281a..bdf841a 100644
--- a/objects/calculator/calculator.gd
+++ b/scripts/expr_validator.gd
@@ -1,19 +1,17 @@
 ## 用于判定表达式 `expr` 是否满足通关要求的脚本。
 ## 一般情况下只需要使用 `Array check(expr: String, req_pos: Array)` 即可，其他不需要使用。
+class_name ExprValidator
 
 
-extends Node
-
-
-func is_alpha(ch: String) -> bool: ## 判断字符 ch 是否为字母。
+static func is_alpha(ch: String) -> bool: ## 判断字符 ch 是否为字母。
 	return (ch >= 'A' and ch <= 'Z') or (ch >= 'a' and ch <= 'z')
-func is_eye(ch: String) -> bool: ## 判断字符 ch 是否为眼睛。
+static func is_eye(ch: String) -> bool: ## 判断字符 ch 是否为眼睛。
 	return ch == "*" or ch == "="
-func is_left_mouth(ch: String) -> bool: ## 判断字符 ch 是否为左边的嘴巴。
+static func is_left_mouth(ch: String) -> bool: ## 判断字符 ch 是否为左边的嘴巴。
 	return ch == "q" or ch == "d" or ch == "<"
-func is_right_mouth(ch: String) -> bool:  ## 判断字符 ch 是否为右边的嘴巴。
+static func is_right_mouth(ch: String) -> bool:  ## 判断字符 ch 是否为右边的嘴巴。
 	return ch == "P" or ch == "b" or ch == "D" or ch == ">"
-func is_smile(string: String) -> bool:  ## 判断长度为 2 的字符串 string 是否为笑脸。
+static func is_smile(string: String) -> bool:  ## 判断长度为 2 的字符串 string 是否为笑脸。
 	return (is_left_mouth(string[0]) and is_eye(string[1])) or (is_eye(string[0]) and is_right_mouth(string[1]))
 
 """
@@ -23,44 +21,78 @@ bracl: (
 bracr: )
 val: Q/0/1
 
-左/右	*	<	(	)	Q
-*		0	0	1	0	1
-<		0	1	1	0	1
-(		0	0	1	0	1
-)		1	1	1	1	1
-Q		1	1	1	1	1
+左/右	*	<	(	)	Q	0
+*		0	0	1	0	1	1
+<		0	1	1	0	1	1
+(		0	0	1	0	1	1
+)		1	1	1	1	1	1
+Q		1	1	1	1	1	0
+0		1	1	1	1	0	0
 """
 
 """
-左/右	*	<	(	)	Q
+左/右	*	<	(	)	Q/0
 *		/	/	0	/	0
 <		/	0	0	/	0
 (		/	/	0	/	0
 )		0	0	1	0	1
-Q		0	0	1	0	1
+Q/0		0	0	1	0	1
 """
 
-const IS_PAIR_VALID := [[0, 0, 1, 0, 1], [0, 1, 1, 0, 1], [0, 0, 1, 0, 1], [1, 1, 1, 1, 1], [1, 1, 1, 1, 1]]
+const IS_PAIR_VALID := [
+	[0, 0, 1, 0, 1, 1], 
+	[0, 1, 1, 0, 1, 1], 
+	[0, 0, 1, 0, 1, 1], 
+	[1, 1, 1, 1, 1, 1], 
+	[1, 1, 1, 1, 1, 0], 
+	[1, 1, 1, 1, 0, 0]
+]
 
-enum {OP, COMP, BRAC_L, BRAC_R, VAL}
+enum {OP, COMP, BRACL, BRACR, VAR, CONST}
 
 
-func get_char_type(ch: String) -> int:
+static func get_char_type(ch: String) -> int:
 	if ch == "*" or ch == "+":
 		return OP
 	elif ch == "<" or ch == "=" or ch == ">":
 		return COMP
 	elif ch == "(":
-		return BRAC_L
+		return BRACL
 	elif ch == ")":
-		return BRAC_R
+		return BRACR
+	elif ch == "0" or ch == "1":
+		return CONST
+	elif is_alpha(ch):
+		return VAR
+	else:
+		push_error("get_char_type(%s) is undefined" % ch)
+		return -1
+	
+static func get_char_type_enum_name(value: int) -> String:
+	if value == OP:
+		return "OP"
+	elif value == COMP:
+		return "COMP"
+	elif value == BRACL:
+		return "BRACL"
+	elif value == BRACR:
+		return "BRACR"
+	elif value == VAR:
+		return "VAR"
+	elif value == CONST:
+		return "CONST"
 	else:
-		return VAL
+		push_error("get_char_type_enum_name(%d) is undefined" % value)
+		return "ERR"
 
-func has_implict_prod(string: String) -> bool:
-	return get_char_type(string[0]) in [BRAC_R, VAL] and get_char_type(string[1]) in [BRAC_L, VAL]
+static func get_char_type_as_str(ch: String) -> String:
+	return get_char_type_enum_name(get_char_type(ch))
+	
 	
-func get_priority(ch: String) -> int:
+static func has_implict_prod(string: String) -> bool:
+	return get_char_type(string[0]) in [BRACR, VAR, CONST] and get_char_type(string[1]) in [BRACL, VAR, CONST]
+	
+static func get_priority(ch: String) -> int:
 	if ch == "*":
 		return 4
 	elif ch == "+":
@@ -78,7 +110,7 @@ func get_priority(ch: String) -> int:
 
 
 ## 将中缀表达式 expr 转为后缀表达式并返回（不判断 expr 的合法性）。
-func infix_to_suffix(expr: String) -> String:
+static func infix_to_suffix(expr: String) -> String:
 	var opt_stack: Array = []
 	var res := ""
 	var pre_ch := "@"
@@ -93,8 +125,8 @@ func infix_to_suffix(expr: String) -> String:
 			
 			
 			
-		print("ch=", ch, " stk=", opt_stack, " res=", res)
-		if get_char_type(ch) == VAL:
+		#print("ch=", ch, " stk=", opt_stack, " res=", res)
+		if get_char_type(ch) in [VAR, CONST]:
 			res += ch
 		elif ch == "(":
 			opt_stack.push_back(ch)
@@ -119,14 +151,14 @@ func infix_to_suffix(expr: String) -> String:
 
 	if get_char_type(res[len(res) - 1]) == COMP:
 		res += "@"
+	#prints(expr, res)
 	
-	prints(expr, res)
 	return res
 	
 
 
 ## 计算后缀表达式 expr 的值，其中变量的值给定，放在字典 var_values 中（不判断 expr 的合法性）。
-func calculate_value(expr: String, var_values: Dictionary) -> bool:
+static func calculate_value(expr: String, var_values: Dictionary) -> bool:
 	var stack: Array = []
 	var val := false
 
@@ -138,7 +170,7 @@ func calculate_value(expr: String, var_values: Dictionary) -> bool:
 			val = false
 		
 		
-		elif get_char_type(ch) == VAL:
+		elif get_char_type(ch) in [VAR, CONST]:
 			if is_alpha(ch):
 				stack.push_back(var_values[ch])
 			else:
@@ -166,10 +198,10 @@ func calculate_value(expr: String, var_values: Dictionary) -> bool:
 ## 判断表达式 expr 是否合法（不检查括号匹配）。
 ##
 ## 合法返回 []，否则返回不合法的下标。
-func check_valid(expr: String) -> Array:
-	if get_char_type(expr[0]) != BRAC_L and get_char_type(expr[0]) != VAL:
+static func check_valid(expr: String) -> Array:
+	if get_char_type(expr[0]) != BRACL and get_char_type(expr[0]) not in [VAR, CONST]:
 		return [0]
-	if get_char_type(expr[len(expr) - 1]) != BRAC_R and get_char_type(expr[len(expr) - 1]) != VAL:
+	if get_char_type(expr[len(expr) - 1]) != BRACR and get_char_type(expr[len(expr) - 1]) not in [VAR, CONST]:
 		return [len(expr) - 1]
 	for i in range(len(expr) - 1):
 		if not IS_PAIR_VALID[get_char_type(expr[i])][get_char_type(expr[i + 1])]:
@@ -192,24 +224,25 @@ func check_valid(expr: String) -> Array:
 	
 ## 判断表达式 expr 是否满足笑脸要求。
 ##
-## 合法返回 -1，否则返回不为笑脸的最小字符下标。
-func check_smile(expr: String, req_pos: Array) -> int:
+## 合法返回 []，否则返回不为笑脸的字符下标列表。
+static func check_smile(expr: String, req_pos: Array) -> Array:
+	var res := []
 	for i in req_pos:
 		if (i == 0 or not is_smile(expr.substr(i - 1, 2))) and (i == len(expr) - 1 or not is_smile(expr.substr(i, 2))):
-			return i
-	return -1
+			res.append(i)
+	return res
 	
 	
 ## 判断表达式 expr 是否恒为真（不检查是否合法）。
 ##
 ## 合法返回空字典，否则一种使得表达式为假的变量取值。
-func check_always_true(expr: String) -> Dictionary:
+static func check_always_true(expr: String) -> Dictionary:
 	var var_values: Dictionary = {} # var_values[var] 获取 var 的值。类型：Dictionary[String, bool]
 	var var_names := [] # 变量名称列表
 	
 	# 中缀转后缀
 	expr = infix_to_suffix(expr)
-	print(expr)
+	#print(expr)
 	
 	for ch in expr:
 		if is_alpha(ch) and not var_names.has(ch):
@@ -232,7 +265,7 @@ func check_always_true(expr: String) -> Dictionary:
 ## 若表达式不恒为正，返回 ["NOT_ALWAYS_TRUE", var_values]，其中 var_values: Dictionary[String, bool] 是一种使得表达式为假的变量取值。
 ## 否则符合要求，返回 ["OK", 200]。
 
-func check(expr: String, req_pos: Array) -> Array:	
+static func check(expr: String, req_pos: Array) -> Array:	
 	var tmp
 
 	
@@ -243,7 +276,7 @@ func check(expr: String, req_pos: Array) -> Array:
 	
 	# 判断笑脸要求
 	tmp = check_smile(expr, req_pos)
-	if tmp != -1:
+	if tmp != []:
 		return ["SMILE_UNSATISFIED", tmp]
 	
 	# 判断是否恒为正
@@ -254,7 +287,7 @@ func check(expr: String, req_pos: Array) -> Array:
 	return ["OK", 200]
 
 
-func _ready():
+static func test():
 	#check("q*Pq*bd*b=D", [])
 	check("0=P<>P", [])	
 	#assert(check("(1=P)+(0=P)", []) == ["OK", 200], "9")
@@ -267,8 +300,3 @@ func _ready():
 	#assert(check("1+P=(0+)", [3]) == ["INVALID", [6, 7]], "4")
 	#
 	#assert(check("P+Q=P", [3]) == ["NOT_ALWAYS_TRUE", {"P": false, "Q": true}], "6")
-	
-	
-
-func _process(_delta):
-	pass
diff --git a/scripts/image_lib.gd b/scripts/image_lib.gd
new file mode 100644
index 0000000..dc9224e
--- /dev/null
+++ b/scripts/image_lib.gd
@@ -0,0 +1,50 @@
+class_name ImageLib
+
+const PALETTE = {
+	"red": Color("#dd4132"),
+	"golden": Color("#f5df4d"),
+	
+	"orange": Color("#ffb463"),
+	"card-op": Color("#ffb463"),
+	
+	"skyblue": Color("#c2fdff"),
+	"card-bracl": Color("#c2fdff"),
+	"card-bracr": Color("#c2fdff"),
+	
+	"lightblue": Color("#8eacf3"),
+	"card-var": Color("#8eacf3"),
+
+	"lightgreen": Color("#8ff297"),
+	"card-comp": Color("#8ff297"),
+	
+	"sliver": Color("#f0f0f0"),
+	"card-const": Color("#f0f0f0"),
+
+	"default": Color.BLACK,
+}
+
+static func change_color(image: Texture2D, old_color: Color, new_color: Color) -> Texture2D:
+	var new_texture = image.get_image()
+	for x in range(new_texture.get_width()):
+		for y in range(new_texture.get_height()):
+			var color = new_texture.get_pixel(x, y)
+			if color == old_color:
+				new_texture.set_pixel(x, y, new_color)
+	return ImageTexture.create_from_image(new_texture)
+
+static func update_animation(
+	sprite: AnimatedSprite2D,
+	start: int,
+	n: int,
+	step: int, 
+	path_pattern: String,
+	old_color: Color,
+	new_color: Color
+) -> void:
+	var animation_id = "%d_%d_%d_%s" % [start, n, step, new_color.to_html()]
+	if not sprite.sprite_frames.has_animation(animation_id):
+		sprite.sprite_frames.add_animation(animation_id)
+		for i in range(n):
+			var image = load(path_pattern % (i * step + start))
+			sprite.sprite_frames.add_frame(animation_id, ImageLib.change_color(image, old_color, new_color))
+	sprite.play(animation_id)