diff --git a/lib/phlex_ui/attribute_merger.rb b/lib/phlex_ui/attribute_merger.rb
deleted file mode 100644
index 378fd37..0000000
--- a/lib/phlex_ui/attribute_merger.rb
+++ /dev/null
@@ -1,64 +0,0 @@
-module PhlexUI
-  class AttributeMerger
-    attr_reader :default_attrs, :user_attrs
-
-    def initialize(default_attrs, user_attrs)
-      @default_attrs = flatten_hash(default_attrs)
-      @user_attrs = flatten_hash(user_attrs)
-    end
-
-    # @return [String]
-    # any key that ends with ! will override the default value
-    # ex: if default_attrs = { class: "text-right" }, user_attrs = { class!: "text-left" }
-    # the result will be { class: "text-left }
-    def call
-      merged_attrs = merge_hashes(default_attrs, user_attrs)
-      mix(merged_attrs, user_attrs)
-    end
-
-    private
-
-    # @return [Hash]
-    def mix(*args)
-      args.each_with_object({}) do |object, result|
-        result.merge!(object) do |_key, old, new|
-          case new
-          when Hash
-            old.is_a?(Hash) ? mix(old, new) : new
-          when Array
-            old.is_a?(Array) ? (old + new) : new
-          when String
-            old.is_a?(String) ? "#{old} #{new}" : new
-          else
-            new
-          end
-        end
-
-        result.transform_keys! do |key|
-          key.end_with?("!") ? key.name.chop.to_sym : key
-        end
-      end
-    end
-
-    def flatten_hash(hash, parent_key = "", result_hash = {})
-      hash.each do |key, value|
-        new_key = parent_key.empty? ? key : :"#{parent_key}_#{key}"
-        if value.is_a? Hash
-          flatten_hash(value, new_key, result_hash)
-        else
-          result_hash[new_key] = value
-        end
-      end
-      result_hash
-    end
-
-    def merge_hashes(hash1, hash2)
-      flat_hash1 = flatten_hash(hash1)
-      flat_hash2 = flatten_hash(hash2)
-
-      flat_hash1.merge(flat_hash2) do |key, oldval, newval|
-        "#{oldval} #{newval}"
-      end
-    end
-  end
-end
diff --git a/lib/phlex_ui/base.rb b/lib/phlex_ui/base.rb
index be1db55..e9713d2 100644
--- a/lib/phlex_ui/base.rb
+++ b/lib/phlex_ui/base.rb
@@ -7,7 +7,7 @@ class Base < Phlex::HTML
     attr_reader :attrs
 
     def initialize(**user_attrs)
-      @attrs = PhlexUI::AttributeMerger.new(default_attrs, user_attrs).call
+      @attrs = mix(default_attrs, user_attrs)
       @attrs[:class] = ::TailwindMerge::Merger.new.merge(@attrs[:class]) if @attrs[:class]
     end
 
diff --git a/lib/rbui/attribute_merger.rb b/lib/rbui/attribute_merger.rb
deleted file mode 100644
index 0573ae3..0000000
--- a/lib/rbui/attribute_merger.rb
+++ /dev/null
@@ -1,65 +0,0 @@
-module RBUI
-  class AttributeMerger
-    attr_reader :default_attrs, :user_attrs
-
-    def initialize(default_attrs, user_attrs)
-      @default_attrs = flatten_hash(default_attrs)
-      @user_attrs = flatten_hash(user_attrs)
-    end
-
-    # @return [String]
-    # any key that ends with ! will override the default value
-    # ex: if default_attrs = { class: "text-right" }, user_attrs = { class!: "text-left" }
-    # the result will be { class: "text-left }
-    def call
-      merged_attrs = merge_hashes(default_attrs, user_attrs)
-      mix(merged_attrs, user_attrs)
-    end
-
-    private
-
-    # @return [Hash]
-    def mix(*args)
-      args.each_with_object({}) do |object, result|
-        result.merge!(object) do |_key, old, new|
-          case new
-          when Hash
-            old.is_a?(Hash) ? mix(old, new) : new
-          when Array
-            old.is_a?(Array) ? (old + new) : new
-          when String
-            value = "#{old} #{new}".split.uniq.join(" ")
-            old.is_a?(String) ? value : new
-          else
-            new
-          end
-        end
-
-        result.transform_keys! do |key|
-          key.end_with?("!") ? key.name.chop.to_sym : key
-        end
-      end
-    end
-
-    def flatten_hash(hash, parent_key = "", result_hash = {})
-      hash.each do |key, value|
-        new_key = parent_key.empty? ? key : :"#{parent_key}_#{key}"
-        if value.is_a? Hash
-          flatten_hash(value, new_key, result_hash)
-        else
-          result_hash[new_key] = value
-        end
-      end
-      result_hash
-    end
-
-    def merge_hashes(hash1, hash2)
-      flat_hash1 = flatten_hash(hash1)
-      flat_hash2 = flatten_hash(hash2)
-
-      flat_hash1.merge(flat_hash2) do |key, oldval, newval|
-        "#{oldval} #{newval}"
-      end
-    end
-  end
-end
diff --git a/lib/rbui/base.rb b/lib/rbui/base.rb
index 20cfcfb..7920f3d 100644
--- a/lib/rbui/base.rb
+++ b/lib/rbui/base.rb
@@ -7,7 +7,7 @@ class Base < Phlex::HTML
     attr_reader :attrs
 
     def initialize(**user_attrs)
-      @attrs = AttributeMerger.new(default_attrs, user_attrs).call
+      @attrs = mix(default_attrs, user_attrs)
       @attrs[:class] = ::TailwindMerge::Merger.new.merge(@attrs[:class]) if @attrs[:class]
     end
 
diff --git a/lib/rbui/theme_toggle/theme_toggle.rb b/lib/rbui/theme_toggle/theme_toggle.rb
index ba27112..3a14041 100644
--- a/lib/rbui/theme_toggle/theme_toggle.rb
+++ b/lib/rbui/theme_toggle/theme_toggle.rb
@@ -7,12 +7,12 @@ def view_template(&)
     end
 
     def light_mode(**user_attrs, &)
-      light_attrs = AttributeMerger.new(default_light_attrs, user_attrs).call
+      light_attrs = mix(default_light_attrs, user_attrs)
       div(**light_attrs, &)
     end
 
     def dark_mode(**user_attrs, &)
-      dark_attrs = AttributeMerger.new(default_dark_attrs, user_attrs).call
+      dark_attrs = mix(default_dark_attrs, user_attrs)
       div(**dark_attrs, &)
     end