diff --git a/CLAUDE.md b/CLAUDE.md
index a91a8fb..23c7be4 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -25,18 +25,23 @@ Ezdoc is a Ruby gem for creating .docx files using a DSL. The gem generates vali
 
 - **Document** (`lib/ezdoc/document.rb`): Entry point via `Document.create`. Includes the Builder module and maintains a collection of nodes.
 
-- **Builder** (`lib/ezdoc/builder.rb`): DSL methods (`p`, `text`, `b`, `i`, `u`, `ul`, `ol`, `li`, `table`, `tr`, `td`). Uses a format stack for nested formatting and target tracking for content placement.
+- **Builder** (`lib/ezdoc/builder.rb`): DSL methods (`p`, `text`, `h1`-`h6`, `b`, `i`, `u`, `ul`, `ol`, `li`, `table`, `tr`, `td`, `image`). Uses a format stack for nested formatting and target tracking for content placement.
 
-- **Nodes** (`lib/ezdoc/nodes/`): Document element representations (Paragraph, Run, List, ListItem, Table, TableRow, TableCell). All inherit from `Nodes::Base`.
+- **Nodes** (`lib/ezdoc/nodes/`): Document element representations (Paragraph, Run, Image, List, ListItem, Table, TableRow, TableCell). All inherit from `Nodes::Base`.
+
+- **Style** (`lib/ezdoc/style.rb`): Style definitions with text properties (bold, italic, color, size, font) and paragraph properties (align, indent, spacing).
 
 - **Package** (`lib/ezdoc/package.rb`): Assembles the docx ZIP structure using rubyzip. Coordinates XML generation.
 
 - **XML generators** (`lib/ezdoc/xml/`): Generate OOXML-compliant XML:
-  - `DocumentXml`: Main content with paragraphs, lists, tables
+  - `DocumentXml`: Main content with paragraphs, lists, tables, images
+  - `StylesXml`: styles.xml with built-in and custom styles
   - `ContentTypes`: [Content_Types].xml
   - `Relationships`: .rels files
   - `Numbering`: numbering.xml for lists
 
+- **ImageDimensions** (`lib/ezdoc/image_dimensions.rb`): Uses fastimage gem to read image dimensions for EMU calculations.
+
 ### Data Flow
 
 1. User calls DSL methods on Document
diff --git a/README.md b/README.md
index f5be899..91142c2 100644
--- a/README.md
+++ b/README.md
@@ -69,6 +69,93 @@ Ezdoc::Document.create("output.docx") do |doc|
 end
 ```
 
+### Headings
+
+Use `h1` through `h6` for document headings:
+
+```ruby
+Ezdoc::Document.create("output.docx") do |doc|
+  doc.h1 "Document Title"
+  doc.h2 "Chapter 1"
+  doc.h3 "Section 1.1"
+  doc.h4 "Subsection"
+  doc.h5 "Minor heading"
+  doc.h6 "Smallest heading"
+
+  # Headings with formatted content
+  doc.h2 do
+    doc.text "Chapter with "
+    doc.i { doc.text "emphasis" }
+  end
+end
+```
+
+### Styles
+
+Ezdoc includes built-in styles and supports custom style definitions.
+
+#### Built-in Styles
+
+```ruby
+Ezdoc::Document.create("output.docx") do |doc|
+  doc.p "This is a title", style: :title
+  doc.p "A subtitle", style: :subtitle
+  doc.p "A quotation", style: :quote
+  doc.p "puts 'code'", style: :code
+end
+```
+
+#### Custom Styles
+
+Define your own styles with text and paragraph properties:
+
+```ruby
+Ezdoc::Document.create("output.docx") do |doc|
+  # Define custom styles
+  doc.define_style :warning,
+    bold: true,
+    color: "FF0000",
+    size: 14
+
+  doc.define_style :note,
+    italic: true,
+    color: "0066CC",
+    font: "Georgia"
+
+  doc.define_style :centered,
+    align: :center,
+    size: 12
+
+  # Apply to paragraphs
+  doc.p "Warning message!", style: :warning
+  doc.p "Centered text", style: :centered
+
+  # Apply to text runs
+  doc.p do
+    doc.text "Normal text, "
+    doc.text "important!", style: :warning
+    doc.text ", and "
+    doc.text "a note", style: :note
+  end
+end
+```
+
+#### Style Properties
+
+**Text properties:**
+- `bold: true/false`
+- `italic: true/false`
+- `underline: true/false`
+- `color: "FF0000"` (hex RGB)
+- `size: 14` (points)
+- `font: "Arial"` (font family)
+
+**Paragraph properties:**
+- `align: :left / :center / :right / :justify`
+- `indent: 720` (twips, 1 inch = 1440 twips)
+- `spacing_before: 240` (twips)
+- `spacing_after: 240` (twips)
+
 ### Lists
 
 #### Bullet Lists
@@ -202,12 +289,14 @@ end
 
 | Method | Description |
 |--------|-------------|
-| `p(text)` | Create a paragraph with text |
-| `p { }` | Create a paragraph with block content |
-| `text(value)` | Add text to the current context |
+| `p(text, style:)` | Create a paragraph with text and optional style |
+| `p(style:) { }` | Create a paragraph with block content and optional style |
+| `text(value, style:)` | Add text with optional style to the current context |
+| `h1(text)` - `h6(text)` | Create headings (level 1-6) |
 | `b { }` | Bold formatting |
 | `i { }` | Italic formatting |
 | `u { }` | Underline formatting |
+| `define_style(name, **props)` | Define a custom style |
 | `ul { }` | Bullet list |
 | `ol { }` | Numbered list |
 | `li(text)` | List item with text |
diff --git a/examples/full_demo.rb b/examples/full_demo.rb
new file mode 100755
index 0000000..dc89e8d
--- /dev/null
+++ b/examples/full_demo.rb
@@ -0,0 +1,182 @@
+#!/usr/bin/env ruby
+# frozen_string_literal: true
+
+# Full demo of all Ezdoc features
+# Run with: bundle exec ruby examples/full_demo.rb
+
+require_relative "../lib/ezdoc"
+
+OUTPUT_FILE = File.expand_path("../example.docx", __dir__)
+FIXTURES_DIR = File.expand_path("../test/fixtures", __dir__)
+
+Ezdoc::Document.create(OUTPUT_FILE) do |doc|
+  # ============================================================================
+  # Custom Styles
+  # ============================================================================
+  doc.define_style :highlight, bold: true, color: "FF6600"
+  doc.define_style :success, color: "228B22", italic: true
+  doc.define_style :centered_large, align: :center, size: 16, bold: true
+
+  # ============================================================================
+  # Title and Introduction
+  # ============================================================================
+  doc.h1 "Ezdoc Feature Demo"
+  doc.p "A comprehensive example of all supported features", style: :subtitle
+
+  # ============================================================================
+  # 1. Text Formatting
+  # ============================================================================
+  doc.h2 "1. Text Formatting"
+  doc.p do
+    doc.text "This paragraph demonstrates "
+    doc.b { doc.text "bold" }
+    doc.text ", "
+    doc.i { doc.text "italic" }
+    doc.text ", "
+    doc.u { doc.text "underlined" }
+    doc.text ", and "
+    doc.b do
+      doc.i do
+        doc.u { doc.text "combined" }
+      end
+    end
+    doc.text " formatting."
+  end
+
+  # ============================================================================
+  # 2. Headings
+  # ============================================================================
+  doc.h2 "2. Headings"
+  doc.h3 "This is Heading 3"
+  doc.h4 "This is Heading 4"
+  doc.h5 "This is Heading 5"
+  doc.h6 "This is Heading 6"
+
+  # ============================================================================
+  # 3. Built-in Styles
+  # ============================================================================
+  doc.h2 "3. Built-in Styles"
+  doc.p "This is styled as a title", style: :title
+  doc.p "This is styled as a subtitle", style: :subtitle
+  doc.p "This is styled as a quote - perfect for citations and quotations.", style: :quote
+  doc.p "def hello; puts \"world\"; end", style: :code
+
+  # ============================================================================
+  # 4. Custom Styles
+  # ============================================================================
+  doc.h2 "4. Custom Styles"
+  doc.p "This text uses our custom highlight style!", style: :highlight
+  doc.p do
+    doc.text "Mixed styles: "
+    doc.text "success message", style: :success
+    doc.text " and "
+    doc.text "highlighted text", style: :highlight
+    doc.text " in one paragraph."
+  end
+  doc.p "Centered and large text", style: :centered_large
+
+  # ============================================================================
+  # 5. Lists
+  # ============================================================================
+  doc.h2 "5. Lists"
+
+  doc.h3 "Bullet List"
+  doc.ul do
+    doc.li "First item"
+    doc.li "Second item"
+    doc.li do
+      doc.text "Item with "
+      doc.b { doc.text "bold" }
+      doc.text " text"
+    end
+  end
+
+  doc.h3 "Numbered List"
+  doc.ol do
+    doc.li "Step one"
+    doc.li "Step two"
+    doc.li "Step three"
+  end
+
+  # ============================================================================
+  # 6. Tables
+  # ============================================================================
+  doc.h2 "6. Tables"
+  doc.table do
+    doc.tr do
+      doc.td { doc.b { doc.text "Feature" } }
+      doc.td { doc.b { doc.text "Status" } }
+      doc.td { doc.b { doc.text "Notes" } }
+    end
+    doc.tr do
+      doc.td "Paragraphs"
+      doc.td { doc.text "Complete", style: :success }
+      doc.td "Basic text support"
+    end
+    doc.tr do
+      doc.td "Formatting"
+      doc.td { doc.text "Complete", style: :success }
+      doc.td "Bold, italic, underline"
+    end
+    doc.tr do
+      doc.td "Headings"
+      doc.td { doc.text "Complete", style: :success }
+      doc.td "h1 through h6"
+    end
+    doc.tr do
+      doc.td "Styles"
+      doc.td { doc.text "Complete", style: :success }
+      doc.td "Built-in and custom"
+    end
+    doc.tr do
+      doc.td "Images"
+      doc.td { doc.text "Complete", style: :success }
+      doc.td "PNG and JPEG"
+    end
+  end
+
+  # ============================================================================
+  # 7. Images
+  # ============================================================================
+  doc.h2 "7. Images"
+
+  doc.p "Image with explicit dimensions:"
+  doc.p do
+    doc.image File.join(FIXTURES_DIR, "test.png"), width: "2in", height: "2in"
+  end
+
+  doc.p "Inline image with text:"
+  doc.p do
+    doc.text "Before "
+    doc.image File.join(FIXTURES_DIR, "test.jpg"), width: "0.75in", height: "0.75in"
+    doc.text " After"
+  end
+
+  doc.p "Image in a table:"
+  doc.table do
+    doc.tr do
+      doc.td "Description"
+      doc.td do
+        doc.image File.join(FIXTURES_DIR, "test.png"), width: "1in", height: "1in"
+      end
+    end
+  end
+
+  # ============================================================================
+  # 8. Combined Features
+  # ============================================================================
+  doc.h2 "8. Combined Features"
+  doc.p do
+    doc.text "This final paragraph combines "
+    doc.b { doc.text "multiple" }
+    doc.text " "
+    doc.i { doc.text "formatting" }
+    doc.text " options with "
+    doc.text "custom styles", style: :highlight
+    doc.text " to demonstrate the full power of Ezdoc."
+  end
+
+  doc.p "End of demo document.", style: :centered_large
+end
+
+puts "Created #{OUTPUT_FILE}"
diff --git a/lib/ezdoc.rb b/lib/ezdoc.rb
index 4ec96f5..5a3874d 100644
--- a/lib/ezdoc.rb
+++ b/lib/ezdoc.rb
@@ -13,10 +13,12 @@ require_relative "ezdoc/nodes/table"
 require_relative "ezdoc/nodes/table_row"
 require_relative "ezdoc/nodes/table_cell"
 require_relative "ezdoc/image_dimensions"
+require_relative "ezdoc/style"
 require_relative "ezdoc/xml/content_types"
 require_relative "ezdoc/xml/relationships"
 require_relative "ezdoc/xml/document_xml"
 require_relative "ezdoc/xml/numbering"
+require_relative "ezdoc/xml/styles_xml"
 require_relative "ezdoc/builder"
 require_relative "ezdoc/package"
 require_relative "ezdoc/document"
diff --git a/lib/ezdoc/builder.rb b/lib/ezdoc/builder.rb
index 4c81506..1fcfdc0 100644
--- a/lib/ezdoc/builder.rb
+++ b/lib/ezdoc/builder.rb
@@ -2,8 +2,8 @@
 
 module Ezdoc
   module Builder
-    def p(text = nil, &block)
-      para = Nodes::Paragraph.new
+    def p(text = nil, style: nil, &block)
+      para = Nodes::Paragraph.new(style: resolve_style(style))
       if block
         with_target(para, &block)
       elsif text
@@ -12,8 +12,34 @@ module Ezdoc
       @nodes << para
     end
 
-    def text(value)
-      @current_target.add_run(Nodes::Run.new(value, **current_formatting))
+    def text(value, style: nil)
+      formatting = current_formatting.merge(style: resolve_style(style))
+      @current_target.add_run(Nodes::Run.new(value, **formatting))
+    end
+
+    # Heading shortcuts
+    def h1(text = nil, &block)
+      p(text, style: :heading1, &block)
+    end
+
+    def h2(text = nil, &block)
+      p(text, style: :heading2, &block)
+    end
+
+    def h3(text = nil, &block)
+      p(text, style: :heading3, &block)
+    end
+
+    def h4(text = nil, &block)
+      p(text, style: :heading4, &block)
+    end
+
+    def h5(text = nil, &block)
+      p(text, style: :heading5, &block)
+    end
+
+    def h6(text = nil, &block)
+      p(text, style: :heading6, &block)
     end
 
     def image(path, width: nil, height: nil)
@@ -125,5 +151,12 @@ module Ezdoc
 
       raise ArgumentError, "Unsupported image format: #{ext}. Use PNG or JPEG."
     end
+
+    def resolve_style(style_or_name)
+      return nil if style_or_name.nil?
+      return style_or_name if style_or_name.is_a?(Style)
+
+      style(style_or_name) || raise(ArgumentError, "Unknown style: #{style_or_name}")
+    end
   end
 end
diff --git a/lib/ezdoc/document.rb b/lib/ezdoc/document.rb
index d6a3dda..21945c1 100644
--- a/lib/ezdoc/document.rb
+++ b/lib/ezdoc/document.rb
@@ -4,7 +4,7 @@ module Ezdoc
   class Document
     include Builder
 
-    attr_reader :nodes
+    attr_reader :nodes, :styles
 
     def self.create(path, &block)
       doc = new
@@ -22,6 +22,16 @@ module Ezdoc
       @current_row = nil
       @num_id_counter = 0
       @images = {}
+      @styles = {}
+      register_built_in_styles
+    end
+
+    def define_style(name, **properties)
+      @styles[name] = Style.new(name, **properties)
+    end
+
+    def style(name)
+      @styles[name]
     end
 
     def save(path)
@@ -49,8 +59,27 @@ module Ezdoc
     private
 
     def next_image_rid
-      base = lists.any? ? 2 : 1
+      # rId1 = styles.xml (always present)
+      # rId2 = numbering.xml (if lists present)
+      # rId3+ = images
+      base = lists.any? ? 3 : 2
       "rId#{base + @images.size}"
     end
+
+    def register_built_in_styles
+      # Headings
+      define_style :heading1, size: 24, bold: true
+      define_style :heading2, size: 18, bold: true
+      define_style :heading3, size: 14, bold: true
+      define_style :heading4, size: 12, bold: true
+      define_style :heading5, size: 11, bold: true, italic: true
+      define_style :heading6, size: 10, bold: true, italic: true
+
+      # Other built-in styles
+      define_style :title, size: 26, bold: true, align: :center
+      define_style :subtitle, size: 15, italic: true, color: "666666"
+      define_style :quote, italic: true, color: "666666", indent: 720
+      define_style :code, font: "Courier New", size: 10
+    end
   end
 end
diff --git a/lib/ezdoc/nodes/paragraph.rb b/lib/ezdoc/nodes/paragraph.rb
index cb43ae9..ac10acf 100644
--- a/lib/ezdoc/nodes/paragraph.rb
+++ b/lib/ezdoc/nodes/paragraph.rb
@@ -3,11 +3,12 @@
 module Ezdoc
   module Nodes
     class Paragraph < Base
-      attr_reader :runs
+      attr_reader :runs, :style
 
-      def initialize(runs = [])
+      def initialize(runs = [], style: nil)
         super()
         @runs = runs
+        @style = style
       end
 
       def add_run(run)
diff --git a/lib/ezdoc/nodes/run.rb b/lib/ezdoc/nodes/run.rb
index 0831c35..9f4740e 100644
--- a/lib/ezdoc/nodes/run.rb
+++ b/lib/ezdoc/nodes/run.rb
@@ -3,14 +3,15 @@
 module Ezdoc
   module Nodes
     class Run < Base
-      attr_reader :text, :bold, :italic, :underline
+      attr_reader :text, :bold, :italic, :underline, :style
 
-      def initialize(text, bold: false, italic: false, underline: false)
+      def initialize(text, bold: false, italic: false, underline: false, style: nil)
         super()
         @text = text
         @bold = bold
         @italic = italic
         @underline = underline
+        @style = style
       end
     end
   end
diff --git a/lib/ezdoc/package.rb b/lib/ezdoc/package.rb
index cef8547..bf99ebe 100644
--- a/lib/ezdoc/package.rb
+++ b/lib/ezdoc/package.rb
@@ -14,6 +14,7 @@ module Ezdoc
         zipfile.get_output_stream("_rels/.rels") { |f| f.write(relationships_xml) }
         zipfile.get_output_stream("word/_rels/document.xml.rels") { |f| f.write(document_relationships_xml) }
         zipfile.get_output_stream("word/document.xml") { |f| f.write(document_xml) }
+        zipfile.get_output_stream("word/styles.xml") { |f| f.write(styles_xml) }
 
         zipfile.get_output_stream("word/numbering.xml") { |f| f.write(numbering_xml) } if lists?
 
@@ -36,7 +37,7 @@ module Ezdoc
     end
 
     def content_types_xml
-      Xml::ContentTypes.new(has_numbering: lists?, images: images).to_xml
+      Xml::ContentTypes.new(has_numbering: lists?, images: images, has_styles: true).to_xml
     end
 
     def relationships_xml
@@ -44,13 +45,17 @@ module Ezdoc
     end
 
     def document_relationships_xml
-      Xml::DocumentRelationships.new(has_numbering: lists?, images: images).to_xml
+      Xml::DocumentRelationships.new(has_numbering: lists?, images: images, has_styles: true).to_xml
     end
 
     def document_xml
       Xml::DocumentXml.new(@document.nodes).to_xml
     end
 
+    def styles_xml
+      Xml::StylesXml.new(@document.styles).to_xml
+    end
+
     def numbering_xml
       Xml::Numbering.new(@document.lists).to_xml
     end
diff --git a/lib/ezdoc/style.rb b/lib/ezdoc/style.rb
new file mode 100644
index 0000000..95ec42a
--- /dev/null
+++ b/lib/ezdoc/style.rb
@@ -0,0 +1,65 @@
+# frozen_string_literal: true
+
+module Ezdoc
+  class Style
+    attr_reader :name, :bold, :italic, :underline, :color, :size, :font,
+                :align, :indent, :spacing_before, :spacing_after
+
+    ALIGNMENTS = %i[left center right justify].freeze
+
+    def initialize(name, bold: nil, italic: nil, underline: nil, color: nil,
+                   size: nil, font: nil, align: nil, indent: nil,
+                   spacing_before: nil, spacing_after: nil)
+      @name = name
+      @bold = bold
+      @italic = italic
+      @underline = underline
+      @color = normalize_color(color)
+      @size = size
+      @font = font
+      @align = validate_align(align)
+      @indent = indent
+      @spacing_before = spacing_before
+      @spacing_after = spacing_after
+    end
+
+    def style_id
+      name.to_s.split("_").map(&:capitalize).join
+    end
+
+    def display_name
+      name.to_s.split("_").map(&:capitalize).join(" ")
+    end
+
+    def paragraph_properties?
+      !!(align || indent || spacing_before || spacing_after)
+    end
+
+    def text_properties?
+      !!(bold || italic || underline || color || size || font)
+    end
+
+    # Size in half-points for OOXML (14pt = 28 half-points)
+    def size_half_points
+      size ? (size * 2).to_i : nil
+    end
+
+    private
+
+    def normalize_color(color)
+      return nil if color.nil?
+
+      hex = color.to_s.sub(/^#/, "").upcase
+      return hex if hex.match?(/\A[0-9A-F]{6}\z/)
+
+      raise ArgumentError, "Invalid color: #{color}. Use 6-digit hex (e.g., 'FF0000')"
+    end
+
+    def validate_align(align)
+      return nil if align.nil?
+      return align if ALIGNMENTS.include?(align)
+
+      raise ArgumentError, "Invalid alignment: #{align}. Use #{ALIGNMENTS.join(", ")}"
+    end
+  end
+end
diff --git a/lib/ezdoc/xml/content_types.rb b/lib/ezdoc/xml/content_types.rb
index f04fa34..a35611e 100644
--- a/lib/ezdoc/xml/content_types.rb
+++ b/lib/ezdoc/xml/content_types.rb
@@ -5,9 +5,10 @@ module Ezdoc
     class ContentTypes
       NAMESPACE = "http://schemas.openxmlformats.org/package/2006/content-types"
 
-      def initialize(has_numbering: false, images: [])
+      def initialize(has_numbering: false, images: [], has_styles: false)
         @has_numbering = has_numbering
         @images = images
+        @has_styles = has_styles
       end
 
       def to_xml
@@ -24,6 +25,12 @@ module Ezdoc
               PartName: "/word/document.xml",
               ContentType: "application/vnd.openxmlformats-officedocument.wordprocessingml.document.main+xml"
             )
+            if @has_styles
+              xml.Override(
+                PartName: "/word/styles.xml",
+                ContentType: "application/vnd.openxmlformats-officedocument.wordprocessingml.styles+xml"
+              )
+            end
             if @has_numbering
               xml.Override(
                 PartName: "/word/numbering.xml",
diff --git a/lib/ezdoc/xml/document_xml.rb b/lib/ezdoc/xml/document_xml.rb
index f67e2b5..d97cd02 100644
--- a/lib/ezdoc/xml/document_xml.rb
+++ b/lib/ezdoc/xml/document_xml.rb
@@ -42,6 +42,11 @@ module Ezdoc
 
       def render_paragraph(xml, para)
         xml["w"].p do
+          if para.style
+            xml["w"].pPr do
+              xml["w"].pStyle("w:val" => para.style.style_id)
+            end
+          end
           para.runs.each { |run| render_run(xml, run) }
         end
       end
@@ -73,8 +78,9 @@ module Ezdoc
 
       def render_text_run(xml, run)
         xml["w"].r do
-          if run.bold || run.italic || run.underline
+          if run.bold || run.italic || run.underline || run.style
             xml["w"].rPr do
+              xml["w"].rStyle("w:val" => run.style.style_id) if run.style
               xml["w"].b if run.bold
               xml["w"].i if run.italic
               xml["w"].u("w:val" => "single") if run.underline
diff --git a/lib/ezdoc/xml/relationships.rb b/lib/ezdoc/xml/relationships.rb
index 68b5dfa..47a198b 100644
--- a/lib/ezdoc/xml/relationships.rb
+++ b/lib/ezdoc/xml/relationships.rb
@@ -21,24 +21,38 @@ module Ezdoc
 
     class DocumentRelationships
       NAMESPACE = "http://schemas.openxmlformats.org/package/2006/relationships"
+      STYLES_TYPE = "http://schemas.openxmlformats.org/officeDocument/2006/relationships/styles"
+      NUMBERING_TYPE = "http://schemas.openxmlformats.org/officeDocument/2006/relationships/numbering"
       IMAGE_TYPE = "http://schemas.openxmlformats.org/officeDocument/2006/relationships/image"
 
-      def initialize(has_numbering: false, images: [])
+      def initialize(has_numbering: false, images: [], has_styles: false)
         @has_numbering = has_numbering
         @images = images
+        @has_styles = has_styles
       end
 
       def to_xml
         builder = Nokogiri::XML::Builder.new(encoding: "UTF-8") do |xml|
           xml.Relationships(xmlns: NAMESPACE) do
-            if @has_numbering
+            # rId1 = styles.xml (always first when present)
+            if @has_styles
               xml.Relationship(
                 Id: "rId1",
-                Type: "http://schemas.openxmlformats.org/officeDocument/2006/relationships/numbering",
+                Type: STYLES_TYPE,
+                Target: "styles.xml"
+              )
+            end
+
+            # rId2 = numbering.xml (if lists present)
+            if @has_numbering
+              xml.Relationship(
+                Id: "rId2",
+                Type: NUMBERING_TYPE,
                 Target: "numbering.xml"
               )
             end
 
+            # Images start at rId2 or rId3 depending on numbering
             @images.each do |image|
               xml.Relationship(
                 Id: image.rid,
diff --git a/lib/ezdoc/xml/styles_xml.rb b/lib/ezdoc/xml/styles_xml.rb
new file mode 100644
index 0000000..a33a3b0
--- /dev/null
+++ b/lib/ezdoc/xml/styles_xml.rb
@@ -0,0 +1,66 @@
+# frozen_string_literal: true
+
+module Ezdoc
+  module Xml
+    class StylesXml
+      NAMESPACE = "http://schemas.openxmlformats.org/wordprocessingml/2006/main"
+
+      ALIGNMENT_MAP = {
+        left: "left",
+        center: "center",
+        right: "right",
+        justify: "both"
+      }.freeze
+
+      def initialize(styles)
+        @styles = styles
+      end
+
+      def to_xml
+        builder = Nokogiri::XML::Builder.new(encoding: "UTF-8") do |xml|
+          xml.styles("xmlns:w" => NAMESPACE) do
+            xml.parent.namespace = xml.parent.namespace_definitions.find { |ns| ns.prefix == "w" }
+
+            @styles.each_value do |style|
+              render_style(xml, style)
+            end
+          end
+        end
+        builder.to_xml
+      end
+
+      private
+
+      def render_style(xml, style)
+        style_type = style.paragraph_properties? ? "paragraph" : "character"
+
+        xml["w"].style("w:type" => style_type, "w:styleId" => style.style_id) do
+          xml["w"].name("w:val" => style.display_name)
+
+          render_paragraph_properties(xml, style) if style.paragraph_properties?
+          render_run_properties(xml, style) if style.text_properties?
+        end
+      end
+
+      def render_paragraph_properties(xml, style)
+        xml["w"].pPr do
+          xml["w"].jc("w:val" => ALIGNMENT_MAP[style.align]) if style.align
+          xml["w"].ind("w:left" => style.indent.to_s) if style.indent
+          xml["w"].spacing("w:before" => style.spacing_before.to_s) if style.spacing_before
+          xml["w"].spacing("w:after" => style.spacing_after.to_s) if style.spacing_after
+        end
+      end
+
+      def render_run_properties(xml, style)
+        xml["w"].rPr do
+          xml["w"].rFonts("w:ascii" => style.font, "w:hAnsi" => style.font) if style.font
+          xml["w"].sz("w:val" => style.size_half_points.to_s) if style.size
+          xml["w"].color("w:val" => style.color) if style.color
+          xml["w"].b if style.bold
+          xml["w"].i if style.italic
+          xml["w"].u("w:val" => "single") if style.underline
+        end
+      end
+    end
+  end
+end
diff --git a/test/heading_test.rb b/test/heading_test.rb
new file mode 100644
index 0000000..cb47e11
--- /dev/null
+++ b/test/heading_test.rb
@@ -0,0 +1,87 @@
+# frozen_string_literal: true
+
+require "test_helper"
+
+class HeadingTest < Minitest::Test
+  include EzdocTestHelpers
+
+  def test_h1
+    xml = create_doc_and_read_xml { |doc| doc.h1 "Title" }
+
+    assert_includes xml, "<w:pStyle"
+    assert_includes xml, 'w:val="Heading1"'
+    assert_includes xml, "Title"
+  end
+
+  def test_h2
+    xml = create_doc_and_read_xml { |doc| doc.h2 "Chapter" }
+
+    assert_includes xml, 'w:val="Heading2"'
+    assert_includes xml, "Chapter"
+  end
+
+  def test_h3
+    xml = create_doc_and_read_xml { |doc| doc.h3 "Section" }
+
+    assert_includes xml, 'w:val="Heading3"'
+  end
+
+  def test_h4
+    xml = create_doc_and_read_xml { |doc| doc.h4 "Subsection" }
+
+    assert_includes xml, 'w:val="Heading4"'
+  end
+
+  def test_h5
+    xml = create_doc_and_read_xml { |doc| doc.h5 "Minor" }
+
+    assert_includes xml, 'w:val="Heading5"'
+  end
+
+  def test_h6
+    xml = create_doc_and_read_xml { |doc| doc.h6 "Smallest" }
+
+    assert_includes xml, 'w:val="Heading6"'
+  end
+
+  def test_heading_with_block
+    xml = create_doc_and_read_xml do |doc|
+      doc.h1 do
+        doc.text "Part 1 "
+        doc.b { doc.text "Bold" }
+      end
+    end
+
+    assert_includes xml, 'w:val="Heading1"'
+    assert_includes xml, "Part 1 "
+    assert_includes xml, "<w:b/>"
+    assert_includes xml, "Bold"
+  end
+
+  def test_multiple_headings
+    xml = create_doc_and_read_xml do |doc|
+      doc.h1 "Title"
+      doc.h2 "Chapter 1"
+      doc.h3 "Section 1.1"
+      doc.p "Normal paragraph"
+    end
+
+    assert_includes xml, 'w:val="Heading1"'
+    assert_includes xml, 'w:val="Heading2"'
+    assert_includes xml, 'w:val="Heading3"'
+    # Regular paragraph should not have pStyle
+    assert_equal 3, xml.scan("<w:pStyle").count
+  end
+
+  def test_heading_styles_in_styles_xml
+    xml_files = create_doc_and_read_all_xml do |doc|
+      doc.h1 "Test"
+    end
+
+    styles_xml = xml_files["word/styles.xml"]
+    assert styles_xml, "styles.xml should exist"
+    assert_includes styles_xml, 'w:styleId="Heading1"'
+    assert_includes styles_xml, "<w:b/>"
+    assert_includes styles_xml, "<w:sz"
+  end
+end
diff --git a/test/style_test.rb b/test/style_test.rb
new file mode 100644
index 0000000..24c9f57
--- /dev/null
+++ b/test/style_test.rb
@@ -0,0 +1,171 @@
+# frozen_string_literal: true
+
+require "test_helper"
+
+class StyleTest < Minitest::Test
+  include EzdocTestHelpers
+
+  def test_define_custom_style
+    xml_files = create_doc_and_read_all_xml do |doc|
+      doc.define_style :warning, bold: true, color: "FF0000"
+      doc.p "Test", style: :warning
+    end
+
+    styles_xml = xml_files["word/styles.xml"]
+    assert_includes styles_xml, 'w:styleId="Warning"'
+    assert_includes styles_xml, "<w:b/>"
+    assert_includes styles_xml, 'w:val="FF0000"'
+  end
+
+  def test_apply_style_to_paragraph
+    xml = create_doc_and_read_xml do |doc|
+      doc.p "Quote text", style: :quote
+    end
+
+    assert_includes xml, '<w:pStyle w:val="Quote"'
+    assert_includes xml, "Quote text"
+  end
+
+  def test_apply_style_to_text_run
+    xml = create_doc_and_read_xml do |doc|
+      doc.p do
+        doc.text "Normal "
+        doc.text "code", style: :code
+      end
+    end
+
+    assert_includes xml, '<w:rStyle w:val="Code"'
+    assert_includes xml, "code"
+  end
+
+  def test_built_in_styles_exist
+    xml_files = create_doc_and_read_all_xml do |doc|
+      doc.p "Test"
+    end
+
+    styles_xml = xml_files["word/styles.xml"]
+    assert_includes styles_xml, 'w:styleId="Heading1"'
+    assert_includes styles_xml, 'w:styleId="Heading2"'
+    assert_includes styles_xml, 'w:styleId="Title"'
+    assert_includes styles_xml, 'w:styleId="Subtitle"'
+    assert_includes styles_xml, 'w:styleId="Quote"'
+    assert_includes styles_xml, 'w:styleId="Code"'
+  end
+
+  def test_style_with_color
+    xml_files = create_doc_and_read_all_xml do |doc|
+      doc.define_style :red_text, color: "FF0000"
+      doc.p "Red", style: :red_text
+    end
+
+    styles_xml = xml_files["word/styles.xml"]
+    assert_includes styles_xml, 'w:val="FF0000"'
+  end
+
+  def test_style_with_font
+    xml_files = create_doc_and_read_all_xml do |doc|
+      doc.define_style :mono, font: "Courier New"
+      doc.p "Mono", style: :mono
+    end
+
+    styles_xml = xml_files["word/styles.xml"]
+    assert_includes styles_xml, 'w:ascii="Courier New"'
+  end
+
+  def test_style_with_size
+    xml_files = create_doc_and_read_all_xml do |doc|
+      doc.define_style :big, size: 24
+      doc.p "Big", style: :big
+    end
+
+    styles_xml = xml_files["word/styles.xml"]
+    # 24pt = 48 half-points
+    assert_includes styles_xml, 'w:val="48"'
+  end
+
+  def test_style_with_alignment
+    xml_files = create_doc_and_read_all_xml do |doc|
+      doc.define_style :centered, align: :center
+      doc.p "Centered", style: :centered
+    end
+
+    styles_xml = xml_files["word/styles.xml"]
+    assert_includes styles_xml, '<w:jc w:val="center"'
+  end
+
+  def test_styles_xml_generated
+    xml_files = create_doc_and_read_all_xml do |doc|
+      doc.p "Test"
+    end
+
+    assert xml_files["word/styles.xml"], "styles.xml should be generated"
+  end
+
+  def test_styles_xml_in_content_types
+    xml_files = create_doc_and_read_all_xml do |doc|
+      doc.p "Test"
+    end
+
+    content_types = xml_files["[Content_Types].xml"]
+    assert_includes content_types, "/word/styles.xml"
+    assert_includes content_types, "wordprocessingml.styles+xml"
+  end
+
+  def test_styles_xml_in_relationships
+    xml_files = create_doc_and_read_all_xml do |doc|
+      doc.p "Test"
+    end
+
+    rels = xml_files["word/_rels/document.xml.rels"]
+    assert_includes rels, "styles.xml"
+    assert_includes rels, "relationships/styles"
+  end
+
+  def test_unknown_style_raises_error
+    assert_raises(ArgumentError) do
+      Tempfile.create(["test", ".docx"]) do |file|
+        Ezdoc::Document.create(file.path) do |doc|
+          doc.p "Test", style: :nonexistent
+        end
+      end
+    end
+  end
+
+  def test_invalid_color_raises_error
+    assert_raises(ArgumentError) do
+      Ezdoc::Style.new(:bad, color: "invalid")
+    end
+  end
+
+  def test_invalid_alignment_raises_error
+    assert_raises(ArgumentError) do
+      Ezdoc::Style.new(:bad, align: :invalid)
+    end
+  end
+
+  def test_color_normalizes_hash
+    style = Ezdoc::Style.new(:test, color: "#ff0000")
+    assert_equal "FF0000", style.color
+  end
+
+  def test_combined_style_properties
+    xml_files = create_doc_and_read_all_xml do |doc|
+      doc.define_style :fancy,
+                       bold: true,
+                       italic: true,
+                       color: "0000FF",
+                       size: 16,
+                       font: "Arial",
+                       align: :center
+      doc.p "Fancy", style: :fancy
+    end
+
+    styles_xml = xml_files["word/styles.xml"]
+    assert_includes styles_xml, "<w:b/>"
+    assert_includes styles_xml, "<w:i/>"
+    assert_includes styles_xml, 'w:val="0000FF"'
+    assert_includes styles_xml, 'w:val="32"' # 16pt = 32 half-points
+    assert_includes styles_xml, 'w:ascii="Arial"'
+    assert_includes styles_xml, '<w:jc w:val="center"'
+  end
+end