@@ -208,6 +208,11 @@ cursor: pointer;
   text-decoration: underline;
 }
 
+var {
+  font-style: normal;
+  font-family: var(--mono-font);
+}
+
 @media only screen and (max-width: 600px) {
   header > nav {
     display: unset;

@@ -9,6 +9,7 @@ "go.alanpearce.eu/searchix/internal/nixdocs/command"
 	"go.alanpearce.eu/searchix/internal/nixdocs/envvar"
 	"go.alanpearce.eu/searchix/internal/nixdocs/option"
 	"go.alanpearce.eu/searchix/internal/nixdocs/optlink"
+	"go.alanpearce.eu/searchix/internal/nixdocs/variable"
 )
 
 func WithNixDocsExtensions() goldmark.Option {
@@ -19,5 +20,6 @@ optlink.New(),
 		option.New(),
 		command.New(),
 		envvar.New(),
+		variable.New(),
 	)
 }

@@ -0,0 +1,44 @@
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+
+	"github.com/yuin/goldmark"
+	"go.alanpearce.eu/searchix/internal/nixdocs/variable"
+)
+
+func main() {
+	// Create a new Goldmark instance with our variable extension
+	md := goldmark.New(
+		goldmark.WithExtensions(
+			variable.New(),
+		),
+	)
+
+	// Some example Markdown content with variable references
+	src := []byte(`
+# Variable References Example
+
+Nix packages like {var}` + "`pkgs.virtualbox`" + ` and {var}` + "`pkgs.firefox`" + `
+can be installed in your system.
+
+The {var}` + "`services.postgresql.enable`" + ` option enables the PostgreSQL service.
+
+Configuration variables are often found in these contexts:
+- {var}` + "`system.stateVersion`" + ` for system configuration
+- {var}` + "`networking.hostName`" + ` for network settings
+- {var}` + "`users.users.alice`" + ` for user accounts
+`)
+
+	// Convert the markdown to HTML
+	var buf bytes.Buffer
+	if err := md.Convert(src, &buf); err != nil {
+		fmt.Println("Conversion error:", err)
+		os.Exit(1)
+	}
+
+	// Print the HTML output
+	fmt.Println(buf.String())
+}

@@ -0,0 +1,172 @@
+//nolint:wrapcheck
+package variable
+
+import (
+	"bytes"
+
+	"github.com/yuin/goldmark"
+	"github.com/yuin/goldmark/ast"
+	"github.com/yuin/goldmark/parser"
+	"github.com/yuin/goldmark/renderer"
+	"github.com/yuin/goldmark/renderer/html"
+	"github.com/yuin/goldmark/text"
+	"github.com/yuin/goldmark/util"
+)
+
+// Node represents a variable reference node in markdown AST.
+type Node struct {
+	ast.BaseInline
+	VarName []byte
+}
+
+// Inline implements ast.Inline interface.
+func (n *Node) Inline() bool {
+	return true
+}
+
+// Kind implements ast.Node.Kind interface.
+func (n *Node) Kind() ast.NodeKind {
+	return KindVar
+}
+
+// Dump implements ast.Node.Dump interface.
+func (n *Node) Dump(source []byte, level int) {
+	ast.DumpHelper(n, source, level, map[string]string{
+		"VarName": string(n.VarName),
+	}, nil)
+}
+
+// KindVar is a NodeKind for variable nodes.
+var KindVar = ast.NewNodeKind("Var")
+
+// Parser is a Goldmark inline parser for parsing variable nodes.
+//
+// Variable references have the format {var}`pkgs.virtualbox` which will be rendered as
+// a var HTML element with the variable name.
+type Parser struct{}
+
+var _ parser.InlineParser = (*Parser)(nil)
+
+// Trigger reports characters that trigger this parser.
+func (*Parser) Trigger() []byte {
+	return []byte{'{'}
+}
+
+// Parse parses a variable node.
+func (p *Parser) Parse(_ ast.Node, block text.Reader, _ parser.Context) ast.Node {
+	line, segment := block.PeekLine()
+
+	// Check if we have enough characters for {var}`
+	if len(line) < 6 || line[0] != '{' {
+		return nil
+	}
+
+	// Check for {var}` prefix
+	if !bytes.HasPrefix(line, []byte("{var}`")) {
+		return nil
+	}
+
+	// Skip the {var}` prefix
+	line = line[6:]
+	start := segment.Start + 6
+
+	// Find the closing backtick
+	endPos := bytes.IndexByte(line, '`')
+	if endPos < 0 {
+		return nil
+	}
+
+	// Extract the variable name
+	varName := line[:endPos]
+	if len(varName) == 0 {
+		return nil
+	}
+
+	// Create the node
+	n := &Node{
+		VarName: varName,
+	}
+
+	// Set the text segment to include the entire {var}`name` text
+	textSegment := text.NewSegment(segment.Start, start+endPos+1)
+	n.AppendChild(n, ast.NewTextSegment(textSegment))
+
+	// Advance the reader past this node
+	block.Advance(6 + endPos + 1) // {var}` + name + `
+
+	return n
+}
+
+// HTMLRenderer is a renderer for variable nodes.
+type HTMLRenderer struct {
+	html.Config
+}
+
+// NewHTMLRenderer returns a new HTMLRenderer.
+func NewHTMLRenderer(opts ...html.Option) renderer.NodeRenderer {
+	r := &HTMLRenderer{
+		Config: html.NewConfig(),
+	}
+	for _, opt := range opts {
+		opt.SetHTMLOption(&r.Config)
+	}
+
+	return r
+}
+
+// RegisterFuncs implements renderer.NodeRenderer.RegisterFuncs.
+func (r *HTMLRenderer) RegisterFuncs(reg renderer.NodeRendererFuncRegisterer) {
+	reg.Register(KindVar, r.renderVar)
+}
+
+func (r *HTMLRenderer) renderVar(
+	w util.BufWriter,
+	source []byte, //nolint:revive
+	node ast.Node,
+	entering bool,
+) (ast.WalkStatus, error) {
+	if !entering {
+		return ast.WalkContinue, nil
+	}
+
+	n := node.(*Node)
+
+	if _, err := w.WriteString("<var>"); err != nil {
+		return ast.WalkStop, err
+	}
+
+	if _, err := w.Write(n.VarName); err != nil {
+		return ast.WalkStop, err
+	}
+
+	if _, err := w.WriteString("</var>"); err != nil {
+		return ast.WalkStop, err
+	}
+
+	return ast.WalkSkipChildren, nil
+}
+
+// Extension is a goldmark extension for variable references.
+type Extension struct{}
+
+// Extend implements goldmark.Extender.Extend.
+func (e *Extension) Extend(m goldmark.Markdown) {
+	// Register the parser
+	m.Parser().AddOptions(
+		parser.WithInlineParsers(
+			util.Prioritized(new(Parser), 100),
+		),
+	)
+
+	// Register the renderer
+	m.Renderer().AddOptions(
+		renderer.WithNodeRenderers(
+			util.Prioritized(NewHTMLRenderer(), 500),
+		),
+	)
+}
+
+// New returns a new variable extension.
+func New() goldmark.Extender {
+	return &Extension{}
+}

@@ -0,0 +1,78 @@
+package variable
+
+import (
+	"bytes"
+	"testing"
+
+	"github.com/yuin/goldmark"
+)
+
+func TestVarExtension(t *testing.T) {
+	markdown := goldmark.New(
+		goldmark.WithExtensions(
+			New(),
+		),
+	)
+
+	tests := []struct {
+		name     string
+		input    string
+		expected string
+	}{
+		{
+			name:     "basic variable reference",
+			input:    "{var}`pkgs.virtualbox`",
+			expected: "<p><var>pkgs.virtualbox</var></p>\n",
+		},
+		{
+			name:     "variable reference in sentence",
+			input:    "Use {var}`nixpkgs.lib.attrsets` to manipulate attribute sets.",
+			expected: "<p>Use <var>nixpkgs.lib.attrsets</var> to manipulate attribute sets.</p>\n",
+		},
+		{
+			name:  "multiple variable references",
+			input: "Both {var}`config.services.nginx` and {var}`config.services.postgresql` define service configurations.",
+			expected: "<p>Both <var>config.services.nginx</var> and <var>" +
+				"config.services.postgresql</var> define service configurations.</p>\n",
+		},
+		{
+			name:     "incomplete variable reference - no closing backtick",
+			input:    "{var}`MISSING_BACKTICK",
+			expected: "<p>{var}`MISSING_BACKTICK</p>\n",
+		},
+		{
+			name:     "incomplete variable reference - empty variable name",
+			input:    "{var}``",
+			expected: "<p>{var}``</p>\n",
+		},
+		{
+			name:  "variable reference with code block",
+			input: "Set {var}`pkgs.hello` in your `configuration.nix` file.",
+			expected: "<p>Set <var>pkgs.hello</var> " +
+				"in your <code>configuration.nix</code> file.</p>\n",
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			var buf bytes.Buffer
+			if err := markdown.Convert([]byte(test.input), &buf); err != nil {
+				t.Fatalf("Failed to convert markdown: %v", err)
+			}
+
+			if got := buf.String(); got != test.expected {
+				t.Errorf("Expected:\n%q\nGot:\n%q", test.expected, got)
+			}
+		})
+	}
+}
+
+func TestVarNodeKind(t *testing.T) {
+	n := &Node{}
+	if kind := n.Kind(); kind != KindVar {
+		t.Errorf("Expected node kind %v, got %v", KindVar, kind)
+	}
+	if !n.Inline() {
+		t.Error("Expected node to be inline")
+	}
+}