Code-block card and inline-code chip rendering (opt-in)

CHANGELOG.md

@@ -7,6 +7,33 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+- Code-block CARD rendering (opt-in): `CodeBlockStyle.cornerRadius` draws a
+  fenced block as one continuous rounded card spanning the whole block —
+  wrapped lines included — instead of square per-paragraph fills, and
+  `CodeBlockStyle.cardVerticalPadding` pins the hidden fence lines' height so
+  they read as the card's interior padding (fences revert to their natural
+  height while the caret reveals them). Selection stays visible above the
+  card. `nil` (the default) keeps the historical rendering exactly.
+- Inline-code CHIP rendering (opt-in): `InlineCodeStyle.chipCornerRadius`
+  draws a small rounded background hugging each inline `code` span (per
+  wrapped line) with `chipHorizontalPadding` of breathing room, replacing the
+  square glyph-run fill. `MarkdownEditorTheme.inlineCodeBackground` colors the
+  chip (nil = `codeBackground`, then the syntax-highlighter background).
+- Code typography and background knobs: `CodeBlockStyle.fontName` and
+  `InlineCodeStyle.fontName` swap the code face (nil = the
+  syntax-highlighter service's font, as before; inline follows the block
+  face unless set independently), and `MarkdownEditorTheme.codeBackground`
+  replaces the background behind fenced blocks and inline spans (nil = the
+  service's background, as before).
+- Custom heading typeface and color: `HeadingStyle.fontName` renders headings
+  in a specific PostScript face (honored exactly, so the chosen weight is
+  respected; an unresolvable name falls back to the stock bold base font),
+  and `MarkdownEditorTheme.headingText` colors heading text independently of
+  `bodyText` — the `#` glyphs stay on `headingMarker`, and inline constructs
+  inside a heading keep their own ink (both opt-in; the defaults are
+  unchanged).
+
 ## [0.11.0] - 2026-07-31
 
 ### Added

Sources/MarkdownEngine/Configuration/MarkdownEditorConfiguration.swift

@@ -249,21 +249,46 @@ public struct MarkerStyle: Sendable {
 
 /// Styling for fenced code blocks (```language ... ```).
 public struct CodeBlockStyle: Sendable {
+    /// PostScript name of the typeface used for code-block text, for example
+    /// `"GeistMono-Regular"`. `nil` (the default) keeps the historical
+    /// behavior: the syntax-highlighter service's code font. A name that
+    /// doesn't resolve degrades to that service font as well.
+    public var fontName: String?
     /// Code-block font size as a fraction of the document base font size.
     public var fontSizeScale: CGFloat
     /// Vertical paragraph spacing applied above and below the code block.
     public var paragraphSpacing: CGFloat
     /// Left/right indent (in points) so code blocks don't run into the gutter.
     public var horizontalIndent: CGFloat
+    /// Corner radius of the code-block CARD. Setting it opts the block into
+    /// card rendering: one continuous rounded background spanning the whole
+    /// fenced block (wrapped lines included), with the corners rounded on the
+    /// block's first and last lines only. `nil` (the default) keeps the
+    /// historical rendering — a square per-paragraph fill from the
+    /// `.backgroundColor` attribute.
+    public var cornerRadius: CGFloat?
+    /// Interior vertical padding of the card: the hidden fence lines' pinned
+    /// line height, i.e. the space between the card's edge and the first/last
+    /// code line. Only takes effect in card mode while the fences are hidden;
+    /// while the caret reveals the fences they keep their natural code line
+    /// height so editing them stays comfortable. `nil` (the default) keeps
+    /// the fences' natural height.
+    public var cardVerticalPadding: CGFloat?
 
     public init(
+        fontName: String? = nil,
         fontSizeScale: CGFloat = 0.85,
         paragraphSpacing: CGFloat = 2.0,
-        horizontalIndent: CGFloat = 12.0
+        horizontalIndent: CGFloat = 12.0,
+        cornerRadius: CGFloat? = nil,
+        cardVerticalPadding: CGFloat? = nil
     ) {
+        self.fontName = fontName
         self.fontSizeScale = fontSizeScale
         self.paragraphSpacing = paragraphSpacing
         self.horizontalIndent = horizontalIndent
+        self.cornerRadius = cornerRadius
+        self.cardVerticalPadding = cardVerticalPadding
     }
 
     public static let `default` = CodeBlockStyle()
@@ -275,9 +300,32 @@ public struct CodeBlockStyle: Sendable {
 public struct InlineCodeStyle: Sendable {
     /// Inline-code reuses the code block font size scale by default.
     public var fontSizeScale: CGFloat
+    /// PostScript name of the typeface used for inline-code text. `nil`
+    /// (the default) keeps the historical behavior: inline code renders in
+    /// the code-block font. A name that doesn't resolve degrades the same
+    /// way.
+    public var fontName: String?
+    /// Corner radius of the inline-code CHIP. Setting it opts inline `code`
+    /// spans into chip rendering: a small rounded background drawn behind the
+    /// span (per wrapped line) with `chipHorizontalPadding` of breathing room
+    /// on each side, hugging the code text's own height instead of the whole
+    /// line box. `nil` (the default) keeps the historical rendering — a
+    /// square glyph-run fill from the `.backgroundColor` attribute.
+    public var chipCornerRadius: CGFloat?
+    /// Horizontal padding (in points) the chip extends beyond the span's
+    /// first and last glyph. Only read in chip mode.
+    public var chipHorizontalPadding: CGFloat
 
-    public init(fontSizeScale: CGFloat = 0.85) {
+    public init(
+        fontSizeScale: CGFloat = 0.85,
+        fontName: String? = nil,
+        chipCornerRadius: CGFloat? = nil,
+        chipHorizontalPadding: CGFloat = 3.0
+    ) {
         self.fontSizeScale = fontSizeScale
+        self.fontName = fontName
+        self.chipCornerRadius = chipCornerRadius
+        self.chipHorizontalPadding = chipHorizontalPadding
     }
 
     public static let `default` = InlineCodeStyle()
@@ -349,15 +397,30 @@ public struct TaskCheckboxStyle: Sendable {
 /// Per-level heading metrics. Defaults follow the historical Nodes ratios,
 /// which are loosely based on browser default heading sizes.
 public struct HeadingStyle: Sendable {
+    /// PostScript name of the typeface used for heading text, for example
+    /// `"AvenirNext-DemiBold"`. `nil` (the default) keeps the historical
+    /// behavior: headings render in the editor's base font with the bold
+    /// trait added.
+    ///
+    /// The name is honored exactly, so the chosen face's weight and style
+    /// are respected — pick a `-Bold` / `-Semibold` face for heavier
+    /// headings. Emphasis inside a heading still composes on top of it:
+    /// bold / italic add their traits while the family and the per-level
+    /// size are kept. A name that doesn't resolve falls back to the default
+    /// heading font at draw time, so a typo degrades to the stock look
+    /// instead of changing metrics.
+    public var fontName: String?
     /// Font-size multiplier per heading level (1...6).
     public var fontMultipliers: [CGFloat]
     /// Top spacing in `em` units per heading level (1...6).
     public var topSpacingEm: [CGFloat]
 
     public init(
+        fontName: String? = nil,
         fontMultipliers: [CGFloat] = [2.0, 1.5, 1.17, 1.0, 0.83, 0.67],
         topSpacingEm: [CGFloat] = [0.35, 0.30, 0.25, 0.20, 0.15, 0.10]
     ) {
+        self.fontName = fontName
         self.fontMultipliers = fontMultipliers
         self.topSpacingEm = topSpacingEm
     }

Sources/MarkdownEngine/Configuration/MarkdownEditorTheme.swift

@@ -36,6 +36,15 @@ public struct MarkdownEditorTheme: Sendable {
     /// Foreground color for content the engine wants to deemphasize further
     /// than `mutedText` — for example, broken wiki-links.
     public var disabledText: NSColor
+    /// Foreground color for heading text. `nil` (the default) keeps the
+    /// historical behavior: headings render in ``bodyText`` like the rest
+    /// of the document.
+    ///
+    /// Only the heading's own text takes this color. The `#` marker glyphs
+    /// stay on ``headingMarker``, and inline constructs inside a heading
+    /// (links, inline code, extension spans) keep their own colors, exactly
+    /// as they do over ``bodyText``.
+    public var headingText: NSColor?
     /// Foreground color for heading marker glyphs (`#`, `##`, …).
     public var headingMarker: NSColor
 
@@ -79,12 +88,26 @@ public struct MarkdownEditorTheme: Sendable {
     /// Background color used for `==highlight==` inline markup.
     public var highlightColor: NSColor
 
+    // MARK: Code
+
+    /// Background color behind fenced code blocks and inline `` `code` ``
+    /// spans. `nil` (the default) keeps the historical behavior: the
+    /// syntax-highlighter service's background color.
+    public var codeBackground: NSColor?
+
+    /// Background color of the inline-code CHIP
+    /// (``InlineCodeStyle/chipCornerRadius`` set). `nil` (the default) falls
+    /// back to ``codeBackground`` and then to the syntax-highlighter
+    /// service's background color.
+    public var inlineCodeBackground: NSColor?
+
     // MARK: Init
 
     public init(
         bodyText: NSColor = .labelColor,
         mutedText: NSColor = .secondaryLabelColor,
         disabledText: NSColor = .tertiaryLabelColor,
+        headingText: NSColor? = nil,
         headingMarker: NSColor = .gray,
         link: NSColor = .linkColor,
         incompleteLink: NSColor = .systemBlue,
@@ -93,11 +116,14 @@ public struct MarkdownEditorTheme: Sendable {
         latexLightModeText: NSColor = .black,
         latexDarkModeText: NSColor = .white,
         strikethroughColor: NSColor = .labelColor,
-        highlightColor: NSColor = .systemOrange.withAlphaComponent(0.4)
+        highlightColor: NSColor = .systemOrange.withAlphaComponent(0.4),
+        codeBackground: NSColor? = nil,
+        inlineCodeBackground: NSColor? = nil
     ) {
         self.bodyText = bodyText
         self.mutedText = mutedText
         self.disabledText = disabledText
+        self.headingText = headingText
         self.headingMarker = headingMarker
         self.link = link
         self.incompleteLink = incompleteLink
@@ -107,6 +133,8 @@ public struct MarkdownEditorTheme: Sendable {
         self.latexDarkModeText = latexDarkModeText
         self.strikethroughColor = strikethroughColor
         self.highlightColor = highlightColor
+        self.codeBackground = codeBackground
+        self.inlineCodeBackground = inlineCodeBackground
     }
 
     /// System-native palette built from `NSColor` dynamic system colors.