diff --git a/.rubocop.yml b/.rubocop.yml
index d88da1b..069c943 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -1,5 +1,8 @@
+require: rubocop-rspec
+
 AllCops:
-  TargetRubyVersion: 2.3
+  TargetRubyVersion: 3.0
+  NewCops: enable
 
 Naming/FileName:
   Enabled: false
@@ -13,12 +16,15 @@ Naming/AccessorMethodName:
 Style/ClassAndModuleChildren:
   Enabled: false
 
-Metrics/LineLength:
+Layout/LineLength:
   Max: 120
 
 Metrics/MethodLength:
   Enabled: false
 
+Metrics/ModuleLength:
+  Enabled: false
+
 Metrics/AbcSize:
   Enabled: false
 
@@ -46,7 +52,7 @@ Style/Documentation:
 Style/GuardClause:
   Enabled: false
 
-Naming/UncommunicativeMethodParamName:
+Naming/MethodParameterName:
   Enabled: false
 
 Style/EvalWithLocation:
diff --git a/.ruby-version b/.ruby-version
new file mode 100644
index 0000000..fa7adc7
--- /dev/null
+++ b/.ruby-version
@@ -0,0 +1 @@
+3.3.5
diff --git a/Gemfile b/Gemfile
index 9a78deb..692377d 100644
--- a/Gemfile
+++ b/Gemfile
@@ -3,3 +3,9 @@
 source 'https://rubygems.org/'
 
 gemspec
+
+group :development do
+  gem 'rspec'
+  gem 'rubocop'
+  gem 'rubocop-rspec'
+end
diff --git a/Gemfile.lock b/Gemfile.lock
index 8dafb49..8d3b006 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -7,46 +7,55 @@ PATH
 GEM
   remote: https://rubygems.org/
   specs:
-    Ascii85 (1.0.2)
-    afm (0.2.0)
-    ast (2.4.0)
-    diff-lcs (1.2.5)
-    hashery (2.1.1)
-    jaro_winkler (1.5.2)
-    parallel (1.12.1)
-    parser (2.5.3.0)
-      ast (~> 2.4.0)
-    pdf-reader (1.3.3)
-      Ascii85 (~> 1.0.0)
-      afm (~> 0.2.0)
-      hashery (~> 2.0)
-      ruby-rc4
-      ttfunk
-    powerpack (0.1.2)
-    prawn (0.12.0)
-      pdf-reader (>= 0.9.0)
-      ttfunk (~> 1.0.2)
-    rainbow (3.0.0)
-    rspec (2.14.1)
-      rspec-core (~> 2.14.0)
-      rspec-expectations (~> 2.14.0)
-      rspec-mocks (~> 2.14.0)
-    rspec-core (2.14.7)
-    rspec-expectations (2.14.4)
-      diff-lcs (>= 1.1.3, < 2.0)
-    rspec-mocks (2.14.4)
-    rubocop (0.62.0)
-      jaro_winkler (~> 1.5.1)
+    ast (2.4.2)
+    bigdecimal (3.1.8)
+    diff-lcs (1.5.1)
+    json (2.7.2)
+    language_server-protocol (3.17.0.3)
+    matrix (0.4.2)
+    parallel (1.26.3)
+    parser (3.3.5.0)
+      ast (~> 2.4.1)
+      racc
+    pdf-core (0.10.0)
+    prawn (2.5.0)
+      matrix (~> 0.4)
+      pdf-core (~> 0.10.0)
+      ttfunk (~> 1.8)
+    racc (1.8.1)
+    rainbow (3.1.1)
+    regexp_parser (2.9.2)
+    rspec (3.13.0)
+      rspec-core (~> 3.13.0)
+      rspec-expectations (~> 3.13.0)
+      rspec-mocks (~> 3.13.0)
+    rspec-core (3.13.1)
+      rspec-support (~> 3.13.0)
+    rspec-expectations (3.13.3)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.13.0)
+    rspec-mocks (3.13.2)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.13.0)
+    rspec-support (3.13.1)
+    rubocop (1.66.1)
+      json (~> 2.3)
+      language_server-protocol (>= 3.17.0)
       parallel (~> 1.10)
-      parser (>= 2.5, != 2.5.1.1)
-      powerpack (~> 0.1)
+      parser (>= 3.3.0.2)
       rainbow (>= 2.2.2, < 4.0)
+      regexp_parser (>= 2.4, < 3.0)
+      rubocop-ast (>= 1.32.2, < 2.0)
       ruby-progressbar (~> 1.7)
-      unicode-display_width (~> 1.4.0)
-    ruby-progressbar (1.10.0)
-    ruby-rc4 (0.1.5)
-    ttfunk (1.0.3)
-    unicode-display_width (1.4.1)
+      unicode-display_width (>= 2.4.0, < 3.0)
+    rubocop-ast (1.32.3)
+      parser (>= 3.3.1.0)
+    rubocop-rspec (3.1.0)
+      rubocop (~> 1.61)
+    ruby-progressbar (1.13.0)
+    ttfunk (1.8.0)
+      bigdecimal (~> 3.1)
+    unicode-display_width (2.6.0)
 
 PLATFORMS
   ruby
@@ -55,6 +64,7 @@ DEPENDENCIES
   prawn-blank!
   rspec
   rubocop
+  rubocop-rspec
 
 BUNDLED WITH
-   1.17.1
+   2.5.21
diff --git a/Rakefile b/Rakefile
index 9d8f0ac..f102b7a 100644
--- a/Rakefile
+++ b/Rakefile
@@ -19,15 +19,11 @@ end
 gem 'hoe', '>=2.0.0'
 require 'hoe'
 
-require 'spec/version'
-require 'spec/rake/spectask'
-require 'spec/ruby'
-
 Spec::Rake::SpecTask.new('spec') do |t|
   t.spec_files = FileList['spec/**/*.rb']
 end
 
 desc 'Look for TODO and FIXME tags in the code'
-task :todo do
+task todo: :environment do
   egrep(/(FIXME|TODO|TBD)/)
 end
diff --git a/lib/prawn/blank.rb b/lib/prawn/blank.rb
index d9930bc..f14f3cc 100644
--- a/lib/prawn/blank.rb
+++ b/lib/prawn/blank.rb
@@ -91,12 +91,7 @@ def get_actual_page_dimensions(page)
 
       page_rotation = get_page_rotation(page)
 
-      if [90, 270].include?(page_rotation)
-        swap_width = page_width
-
-        page_width  = page_height
-        page_height = swap_width
-      end
+      page_width, page_height = page_height, page_width if [90, 270].include?(page_rotation)
 
       [page_width, page_height]
     end
diff --git a/lib/prawn/blank/appearance.rb b/lib/prawn/blank/appearance.rb
index 3be1826..9bc71e0 100755
--- a/lib/prawn/blank/appearance.rb
+++ b/lib/prawn/blank/appearance.rb
@@ -43,7 +43,7 @@ def xobject_matrix(width, height)
       raise "Unhandled page rotation for xobject_matrix! #{page_rotation}"
     end
 
-    def render(dict)
+    def render(dict, &block)
       dict = {
         Type: :XObject,
         Subtype: :Form,
@@ -51,9 +51,7 @@ def render(dict)
       }.merge(dict)
 
       result = @document.ref!(dict)
-      @document.state.page.stamp_stream(result) do
-        yield
-      end
+      @document.state.page.stamp_stream(result, &block)
       @document.acroform.add_resources(result.data[:Resources])
       result
     end
@@ -82,14 +80,14 @@ def button(element)
     alias button_over button
     alias button_down button
 
-    def checkbox_off(element, _cache_key = :checkbox_off, mousedown = false)
+    def checkbox_off(element, _cache_key = :checkbox_off, mousedown: false)
       element.width = 10 if !element.width || (element.width <= 0)
       element.height = 10 if !element.height || (element.height <= 0)
       width = element.width
       height = element.height
       # style = element.style ||= Prawn::ColorStyle(@document, 'ffffff', '888888')
 
-      style = element.style ||= {
+      element.style ||= {
         BC: [0],
         BG: [1]
       }
@@ -120,17 +118,17 @@ def checkbox_off(element, _cache_key = :checkbox_off, mousedown = false)
     alias checkbox_off_over checkbox_off
     # alias checkbox_off_down checkbox_off
     def checkbox_off_down(element)
-      checkbox_off(element, :checkbox_off_down, :down)
+      checkbox_off(element, :checkbox_off_down, mousedown: true)
     end
 
-    def checkbox_on(element, _cache_key = :checkbox_on, mousedown = false)
+    def checkbox_on(element, _cache_key = :checkbox_on, mousedown: false)
       element.width = 10 if !element.width || (element.width <= 0)
       element.height = 10 if !element.height || (element.height <= 0)
       width = element.width
       height = element.height
       # style = element.style ||= Prawn::ColorStyle(@document, 'ffffff', '888888')
       # border_style = element.border_style ||= Prawn::BorderStyle(@document, 4)
-      style = element.style ||= {
+      element.style ||= {
         BC: [0],
         BG: [1]
       }
@@ -181,7 +179,8 @@ def checkbox_on(element, _cache_key = :checkbox_on, mousedown = false)
       # x y m: Begin a new subpath by moving the current point to coordinates (x, y)
       # x1 y1 x2 y2 x3 y3 c: Append a cubic Bézier curve to the current path
       # x y l: Append a straight line segment from the current point to the point (x, y)
-      # h: Close the current subpath by appending a straight line segment from the current point to the starting point of the subpath.
+      # h: Close the current subpath by appending a straight line segment from the
+      #    current point to the starting point of the subpath.
 
       stream_ref.stream << %(
 #{bg_color} g
@@ -209,10 +208,10 @@ def checkbox_on(element, _cache_key = :checkbox_on, mousedown = false)
     alias checkbox_on_over checkbox_on
     # alias checkbox_on_down checkbox_on
     def checkbox_on_down(element)
-      checkbox_on(element, :checkbox_on_down, :down)
+      checkbox_on(element, :checkbox_on_down, mousedown: true)
     end
 
-    def radio_off(element, cache_key = :radio_off, mousedown = false)
+    def radio_off(element, cache_key = :radio_off, mousedown: false)
       element.width = 10 if !element.width || (element.width <= 0)
       element.height = 10 if !element.height || (element.height <= 0)
       width = element.width
@@ -273,10 +272,10 @@ def radio_off(element, cache_key = :radio_off, mousedown = false)
     alias radio_off_over radio_off
     # alias radio_off_down radio_off
     def radio_off_down(element)
-      radio_off(element, :radio_off_down, :down)
+      radio_off(element, :radio_off_down, mousedown: true)
     end
 
-    def radio_on(element, _cache_key = :radio_on, mousedown = false)
+    def radio_on(element, _cache_key = :radio_on, mousedown: false)
       element.width = 10 if !element.width || (element.width <= 0)
       element.height = 10 if !element.height || (element.height <= 0)
       width = element.width
@@ -340,32 +339,30 @@ def radio_on(element, _cache_key = :radio_on, mousedown = false)
     alias radio_on_over radio_on
     # alias radio_on_down radio_on
     def radio_on_down(element)
-      radio_on(element, :radio_on_down, :down)
+      radio_on(element, :radio_on_down, mousedown: true)
     end
 
     # For DA instead of AP
     def text_field_default_appearance(element)
-      text_style = element.text_style ||= Prawn::TextStyle(@document,"Helvetica",10,'000000')
+      text_style = element.text_style ||= Prawn::TextStyle(@document, 'Helvetica', 10, '000000')
 
       # Set border width to 0, don't add any borders by default
       element.border_style ||= Prawn::BorderStyle(@document, 0)
 
-      if !element.width or element.width <= 0
-        element.width = 100
-      end
-      if !element.height or element.height <= 0
+      element.width = 100 if !element.width || (element.width <= 0)
+      if !element.height || (element.height <= 0)
         element.height = text_style.size + 6 # + 2 * border_style[:W]
       end
       width = element.width
       height = element.height
-      style = element.style || Prawn::ColorStyle(@document,'ffffff','000000')
+      style = element.style || Prawn::ColorStyle(@document, 'ffffff', '000000')
       multiline = element.multiline
       value = element.value
 
       font_ref = document.state.page.fonts[text_style.font_identifier]
 
       descent_ratio = 0.23
-      vertical_offset = text_style.size * descent_ratio + 1.25
+      vertical_offset = (text_style.size * descent_ratio) + 1.25
 
       if value.blank? || value.ascii_only?
         return cached(
@@ -389,66 +386,64 @@ def text_field_default_appearance(element)
           render(
             BBox: [0, 0, width, height],
             FormType: 1,
-            Matrix: xobject_matrix(width, height),
+            Matrix: xobject_matrix(width, height)
           ) do
             document.add_content '/Tx BMC'
             document.canvas do
               document.save_font do
                 document.transparent(element.text_box_opacity || 1) do
-                    document.stroke_color( *denormalize_color(style[:BC]) )
-                    document.fill_color( *denormalize_color(style[:BG]) )
-
-                    # render background
-                    if element.text_box_background_color.present?
-                      document.fill_color(element.text_box_background_color)
-                      document.fill_rectangle( [0, height], width, height)
-                    end
-
-                    # document.line_width(border_style[:W])
-                    # bw = border_style[:W]/2.0
-
-                    next unless value.present?
-
-                    if text_style
-                      document.font(text_style.font, size: text_style.size, style: text_style.style )
-                      document.stroke_color( *text_style.color )
-                      document.fill_color( *text_style.color )
-                    end
-
-                    # document.draw_text(value, at: [0, [0, height - document.font_size - 1.5].max ] )
-
-                    # text_offset_y = [height - document.font_size - 1.5].max
-
-                    text_box_args = {
-                      # at: [0, text_offset_y],
-                      at: [0, height],
-                      width: width,
-                      height: height,
-                      align: element.text_box_align,
-                      valign: element.text_box_valign,
-                      overflow: element.text_box_overflow,
-                      min_font_size: 5,
-                      single_line: element.multiline == 0,
-                      character_spacing: element.text_box_character_spacing,
-                      direction: element.text_box_text_direction,
-                    }
-
-                    text_options = { text: value }
-
-                    if element.text_box_strikethrough
-                      text_options[:styles] = [:strikethrough]
-                    end
-
-                    formatted_text_array = [text_options]
-
-                    begin
-                      document.formatted_text_box(
-                        formatted_text_array,
-                        text_box_args
-                      )
-                    rescue Prawn::Errors::CannotFit
-                      document.draw_text value, at: [0, height], direction: element.text_box_text_direction
-                    end
+                  document.stroke_color(*denormalize_color(style[:BC]))
+                  document.fill_color(*denormalize_color(style[:BG]))
+
+                  # render background
+                  if element.text_box_background_color.present?
+                    document.fill_color(element.text_box_background_color)
+                    document.fill_rectangle([0, height], width, height)
+                  end
+
+                  # document.line_width(border_style[:W])
+                  # bw = border_style[:W]/2.0
+
+                  next if value.blank?
+
+                  if text_style
+                    document.font(text_style.font, size: text_style.size, style: text_style.style)
+                    document.stroke_color(*text_style.color)
+                    document.fill_color(*text_style.color)
+                  end
+
+                  # document.draw_text(value, at: [0, [0, height - document.font_size - 1.5].max ] )
+
+                  # text_offset_y = [height - document.font_size - 1.5].max
+
+                  text_box_args = {
+                    # at: [0, text_offset_y],
+                    at: [0, height],
+                    width: width,
+                    height: height,
+                    align: element.text_box_align,
+                    valign: element.text_box_valign,
+                    overflow: element.text_box_overflow,
+                    min_font_size: 5,
+                    single_line: element.multiline == 0,
+                    character_spacing: element.text_box_character_spacing,
+                    direction: element.text_box_text_direction
+                  }
+
+                  text_options = { text: value }
+
+                  text_options[:styles] = [:strikethrough] if element.text_box_strikethrough
+
+                  formatted_text_array = [text_options]
+
+                  begin
+                    document.formatted_text_box(
+                      formatted_text_array,
+                      text_box_args
+                    )
+                  rescue Prawn::Errors::CannotFit
+                    document.draw_text value, at: [0, height], direction: element.text_box_text_direction
+                  end
                 end
               end
             end
@@ -483,7 +478,7 @@ def text_field_default_appearance(element)
 W
 n
 BT
-#{text_style.to_s}
+#{text_style}
 2 #{vertical_offset} Td
 (#{value}) Tj
 ET
@@ -491,7 +486,6 @@ def text_field_default_appearance(element)
 EMC
       )
       stream_ref
-
     end
 
     protected
@@ -502,11 +496,12 @@ def cached(*args)
 
     def denormalize_color(color)
       s = color.size
-      if s == 1 # gray
+      case s
+      when 1 # gray
         return [0, 0, 0, color[0]]
-      elsif s == 3 # rgb
+      when 3 # rgb
         return Prawn::Graphics::Color.rgb2hex(color.map { |component| component * 255.0 })
-      elsif s == 4 # cmyk
+      when 4 # cmyk
         return color.map { |component| component * 100.0 }
       end
 
diff --git a/lib/prawn/blank/field.rb b/lib/prawn/blank/field.rb
index 20a05f7..3076dca 100644
--- a/lib/prawn/blank/field.rb
+++ b/lib/prawn/blank/field.rb
@@ -3,15 +3,17 @@
 class Prawn::Blank::Field < Prawn::Blank::FieldBase
   # Returns the ZapfDingbats character code for the checkmark (between 3 and 8)
   def check_zapf_char
-    check_char = check_string
-    if check_char&.match?(%r{^&#1000\d;$})
-      check_char = HTMLEntities.new.decode(check_char)
-    end
-    check_char = "✔" unless check_char&.length == 1
-    check_zapf_char = (check_string.ord || 0) - 10000
-    if check_zapf_char < 3 || check_zapf_char > 8
-      check_zapf_char = 4
-    end
+    # TODO: verify intended functionality and consider reimplementation
+    # This code was probably intended to use check_char as a replacement for check_string
+    # Commented out for now to avoid rubocop complaints
+    #
+    # check_char = check_string
+    # if check_char&.match?(%r{^&#1000\d;$})
+    #   check_char = HTMLEntities.new.decode(check_char)
+    # end
+    # check_char = "✔" unless check_char&.length == 1
+    check_zapf_char = (check_string.ord || 0) - 10_000
+    check_zapf_char = 4 if check_zapf_char < 3 || check_zapf_char > 8
     check_zapf_char.to_s
   end
 
diff --git a/lib/prawn/blank/field_base.rb b/lib/prawn/blank/field_base.rb
index bedae14..605b31e 100755
--- a/lib/prawn/blank/field_base.rb
+++ b/lib/prawn/blank/field_base.rb
@@ -29,62 +29,102 @@ class Prawn::Blank::FieldBase < PDF::Core::Reference
   }.freeze
 
   class << self
-    def field_attr_accessor(name, key, inheritable = true)
-      class_eval <<EVAL
-      def #{name}
-        if #{inheritable.inspect} and !@data.key?(#{key.to_sym.inspect}) and self.parent?
-          return self.parent.#{name}
-        end
-        @data[#{key.to_sym.inspect}]
-      end
-      def #{name}=(value)
-        @data[#{key.to_sym.inspect}]=value
-      end
-      def delete_#{name}
-        @data.delete #{key.to_sym.inspect}
-      end
-      def #{name}?
-        if #{inheritable.inspect}
-          @data.key?(#{key.to_sym.inspect}) or ( self.parent? and self.parent.#{name}?)
-        else
-          @data.key? #{key.to_sym.inspect}
-        end
-      end
-      def own_#{name}?
-        @data.key? #{key.to_sym.inspect}
-      end
-EVAL
+    def field_attr_accessor(name, key, inheritable: true)
+      class_eval(
+        # def rect
+        #   if false && !@data.key?(:Rect) && self.parent?
+        #     return self.parent.rect
+        #   end
+        #   @data[:Rect]
+        # end
+        # def rect=(value)
+        #   @data[:Rect]=value
+        # end
+        # def delete_rect
+        #   @data.delete :Rect
+        # end
+        # def rect?
+        #   if false
+        #     @data.key?(:Rect) || (self.parent? && self.parent.rect?)
+        #   else
+        #     @data.key? :Rect
+        #   end
+        # end
+        # def own_rect?
+        #   @data.key? :Rect
+        # end
+        <<~EVAL, __FILE__, __LINE__ + 1
+          def #{name}
+            if #{inheritable.inspect} && !@data.key?(#{key.to_sym.inspect}) && self.parent?
+              return self.parent.#{name}
+            end
+            @data[#{key.to_sym.inspect}]
+          end
+
+          def #{name}=(value)
+            @data[#{key.to_sym.inspect}]=value
+          end
+          def delete_#{name}
+            @data.delete #{key.to_sym.inspect}
+          end
+          def #{name}?
+            if #{inheritable.inspect}
+              @data.key?(#{key.to_sym.inspect}) || (self.parent? && self.parent.#{name}?)
+            else
+              @data.key? #{key.to_sym.inspect}
+            end
+          end
+          def own_#{name}?
+            @data.key? #{key.to_sym.inspect}
+          end
+        EVAL
+      )
     end
 
     def flag_accessor(name, bit, flag_name = 'flags')
       mask = (1 << (bit - 1))
 
-      class_eval <<EVAL
-      def #{name}
-        (self.#{flag_name} || 0) & #{mask.inspect}
-      end
-
-      alias #{name}? #{name}
-
-      def #{name}=(value)
-        if value
-          self.#{flag_name} = (self.#{flag_name} || 0) | #{mask.inspect}
-        else
-          self.#{flag_name} = (self.#{flag_name} || 0) & ~#{mask.inspect}
-        end
-      end
-EVAL
+      class_eval(
+        # def invisible
+        #   (self.aflags || 0) & 1
+        # end
+        #
+        # alias invisible? invisible
+        #
+        # def invisible=(value)
+        #   if value
+        #     self.aflags = (self.aflags || 0) | 1
+        #   else
+        #     self.aflags = (self.aflags || 0) & ~1
+        #   end
+        # end
+        <<~EVAL, __FILE__, __LINE__ + 1
+          def #{name}
+            (self.#{flag_name} || 0) & #{mask.inspect}
+          end
+
+          alias #{name}? #{name}
+
+          def #{name}=(value)
+            if value
+              self.#{flag_name} = (self.#{flag_name} || 0) | #{mask.inspect}
+            else
+              self.#{flag_name} = (self.#{flag_name} || 0) & ~#{mask.inspect}
+            end
+          end
+        EVAL
+      )
     end
   end
 
-  field_attr_accessor :rect, :Rect, false
-  field_attr_accessor :parent, :Parent, false
-  field_attr_accessor :children, :Kids, false
+  field_attr_accessor :rect, :Rect, inheritable: false
+  field_attr_accessor :parent, :Parent, inheritable: false
+  field_attr_accessor :children, :Kids, inheritable: false
   field_attr_accessor :type, :FT
   field_attr_accessor :aflags, :F
   field_attr_accessor :flags, :Ff
-  field_attr_accessor :name, :T, false
-  field_attr_accessor :fullname, :TU, false
+  field_attr_accessor :name, :T, inheritable: false
+  field_attr_accessor :fullname, :TU, inheritable: false
   field_attr_accessor :value, :V
   field_attr_accessor :default_value, :DV
   field_attr_accessor :default_appearance, :DA
@@ -96,18 +136,18 @@ def #{name}=(value)
   field_attr_accessor :options, :Opt
   field_attr_accessor :max_length, :MaxLen
 
-  attr_reader :text_style
-  attr_reader :shrink_to_fit
+  attr_reader :text_style,
+              :shrink_to_fit
 
-  attr_accessor :text_box_opacity
-  attr_accessor :text_box_background_color
-  attr_accessor :text_box_align
-  attr_accessor :text_box_valign
-  attr_accessor :text_box_overflow
-  attr_accessor :text_box_single_line
-  attr_accessor :text_box_character_spacing
-  attr_accessor :text_box_text_direction
-  attr_accessor :text_box_strikethrough
+  attr_accessor :text_box_opacity,
+                :text_box_background_color,
+                :text_box_align,
+                :text_box_valign,
+                :text_box_overflow,
+                :text_box_single_line,
+                :text_box_character_spacing,
+                :text_box_text_direction,
+                :text_box_strikethrough
 
   # Special case for text_style / default_appearance
   # When shrink_to_fit is true, the default_appearance font size is set to 0
@@ -180,8 +220,8 @@ def root?
     !parent?
   end
 
-  def self.create(document, *args, &block)
-    document.state.store.push(new(document.state.store.size + 1, *args, &block))
+  def self.create(document, ...)
+    document.state.store.push(new(document.state.store.size + 1, ...))
   end
 
   def self.from_ref(ref)
@@ -198,7 +238,7 @@ def initialize(id, *args)
 
     options = (args.last.is_a?(Hash) ? args.pop : {})
     options.each do |k, v|
-      send "#{k}=".to_sym, v
+      send :"#{k}=", v
     end
 
     yield self if block_given?
@@ -235,20 +275,19 @@ def validate!
     raise 'Blank: Type must be :Annot ' if data[:Type] != :Annot
     raise 'Blank: Subtype must be :Annot ' if data[:Subtype] != :Widget
 
-    if leaf?
-      raise 'Blank: FT ( Field Type ) must be :Btn, :Tx, :Ch or :Sig ' unless %i[Btn Tx Ch Sig].include type
-    end
+    raise 'Blank: FT ( Field Type ) must be :Btn, :Tx, :Ch or :Sig ' if leaf? && !(%i[Btn Tx Ch Sig].include type)
   end
 
   def finalize(document); end
 
   def denormalize_color(color)
     s = color.size
-    if s == 1 # gray
+    case s
+    when 1 # gray
       return [0, 0, 0, color[0]]
-    elsif s == 3 # rgb
+    when 3 # rgb
       return Prawn::Graphics::Color.rgb2hex(color.map { |component| component * 255.0 })
-    elsif s == 4 # cmyk
+    when 4 # cmyk
       return color.map { |component| component * 100.0 }
     end
 
diff --git a/lib/prawn/blank/text_style.rb b/lib/prawn/blank/text_style.rb
index 8bd7b84..eaf5a14 100755
--- a/lib/prawn/blank/text_style.rb
+++ b/lib/prawn/blank/text_style.rb
@@ -32,9 +32,9 @@ def font_identifier
 
     def color_cmd(color)
       if color[0].is_a? String
-        "rg"
+        'rg'
       else
-        "k"
+        'k'
       end
     end
   end
diff --git a/prawn-blank.gemspec b/prawn-blank.gemspec
index 966d7bd..2c39a60 100644
--- a/prawn-blank.gemspec
+++ b/prawn-blank.gemspec
@@ -3,16 +3,15 @@
 Gem::Specification.new do |s|
   s.name = 'prawn-blank'
   s.version = '0.0.3'
-  s.date = '2013-11-20'
   s.authors = ['HannesG']
   s.email = 'hannes.georg@googlemail.com'
   s.summary = 'This is a experimental library. See the basic example for usage and abilities.'
+  s.required_ruby_version = '>= 3.0'
 
   s.description = 'prawn-blank adds forms to prawn'
   s.files = Dir.glob('{lib}/**/**/*') + ['Rakefile']
   s.require_path = 'lib'
   s.add_dependency 'prawn'
-  s.add_development_dependency('rspec')
-  s.add_development_dependency('rubocop')
   # s.has_rdoc = true
+  s.metadata['rubygems_mfa_required'] = 'true'
 end
diff --git a/spec/base_spec.rb b/spec/base_spec.rb
deleted file mode 100644
index ddb532a..0000000
--- a/spec/base_spec.rb
+++ /dev/null
@@ -1,8 +0,0 @@
-# frozen_string_literal: true
-
-require 'helper'
-describe Prawn::Blank do
-  it 'should run tests!' do
-    true.should_not == false
-  end
-end
diff --git a/spec/prawn/blank_spec.rb b/spec/prawn/blank_spec.rb
new file mode 100644
index 0000000..d3291b8
--- /dev/null
+++ b/spec/prawn/blank_spec.rb
@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+require 'helper'
+describe Prawn::Blank do
+  #  TODO: Write some tests!!!
+  it 'runs tests!' do
+    expect(true).not_to be false # rubocop:disable RSpec/ExpectActual
+  end
+end