.'
+ );
+}
+
+createRoot(rootElement).render(
+
+
+
+);
+`
+);
+
+// ─── src/editor-core/schema/index.ts ─────────────────────────────────────────
+write(
+ 'src/editor-core/schema/index.ts',
+ // NOTE: the heading toDOM uses a JS template literal — the \` and \${} below
+ // are escape sequences so this setup script's own template literal is valid.
+ `import { Schema } from 'prosemirror-model';
+
+/**
+ * Carbon Type document schema.
+ *
+ * Node hierarchy:
+ * doc
+ * ├─ title (exactly one, at the top — the document title)
+ * └─ block+ (paragraphs, headings, blockquotes, code blocks, hr)
+ *
+ * Inline content: text, hard_break
+ * Marks: em, strong, code, link, underline, strikethrough
+ */
+const schema = new Schema({
+ nodes: {
+ doc: {
+ content: 'title block+',
+ },
+
+ title: {
+ content: 'inline*',
+ marks: '',
+ defining: true,
+ parseDOM: [{ tag: 'h1.doc-title' }],
+ toDOM() {
+ return ['h1', { class: 'doc-title' }, 0];
+ },
+ },
+
+ paragraph: {
+ content: 'inline*',
+ marks: 'em strong code link underline strikethrough',
+ group: 'block',
+ parseDOM: [{ tag: 'p' }],
+ toDOM() {
+ return ['p', 0];
+ },
+ },
+
+ heading: {
+ content: 'inline*',
+ marks: 'em strong code link underline strikethrough',
+ group: 'block',
+ defining: true,
+ attrs: { level: { default: 1 } },
+ parseDOM: [
+ { tag: 'h1', getAttrs: () => ({ level: 1 }) },
+ { tag: 'h2', getAttrs: () => ({ level: 2 }) },
+ { tag: 'h3', getAttrs: () => ({ level: 3 }) },
+ { tag: 'h4', getAttrs: () => ({ level: 4 }) },
+ { tag: 'h5', getAttrs: () => ({ level: 5 }) },
+ { tag: 'h6', getAttrs: () => ({ level: 6 }) },
+ ],
+ toDOM(node) {
+ return [\`h\${node.attrs['level'] as number}\`, 0];
+ },
+ },
+
+ blockquote: {
+ content: 'block+',
+ group: 'block',
+ defining: true,
+ parseDOM: [{ tag: 'blockquote' }],
+ toDOM() {
+ return ['blockquote', 0];
+ },
+ },
+
+ code_block: {
+ content: 'text*',
+ marks: '',
+ group: 'block',
+ code: true,
+ defining: true,
+ parseDOM: [{ tag: 'pre', preserveWhitespace: 'full' }],
+ toDOM() {
+ return ['pre', ['code', 0]];
+ },
+ },
+
+ horizontal_rule: {
+ group: 'block',
+ parseDOM: [{ tag: 'hr' }],
+ toDOM() {
+ return ['hr'];
+ },
+ },
+
+ hard_break: {
+ inline: true,
+ group: 'inline',
+ selectable: false,
+ parseDOM: [{ tag: 'br' }],
+ toDOM() {
+ return ['br'];
+ },
+ },
+
+ text: {
+ group: 'inline',
+ },
+ },
+
+ marks: {
+ em: {
+ parseDOM: [{ tag: 'i' }, { tag: 'em' }, { style: 'font-style=italic' }],
+ toDOM() {
+ return ['em', 0];
+ },
+ },
+
+ strong: {
+ parseDOM: [
+ { tag: 'strong' },
+ {
+ tag: 'b',
+ getAttrs: (node) => {
+ const el = node as HTMLElement;
+ return el.style?.fontWeight !== 'normal' ? null : false;
+ },
+ },
+ { style: 'font-weight=bold' },
+ ],
+ toDOM() {
+ return ['strong', 0];
+ },
+ },
+
+ code: {
+ parseDOM: [{ tag: 'code' }],
+ toDOM() {
+ return ['code', 0];
+ },
+ },
+
+ link: {
+ attrs: {
+ href: {},
+ title: { default: null },
+ },
+ inclusive: false,
+ parseDOM: [
+ {
+ tag: 'a[href]',
+ getAttrs(node) {
+ const el = node as HTMLElement;
+ return { href: el.getAttribute('href'), title: el.getAttribute('title') };
+ },
+ },
+ ],
+ toDOM(node) {
+ const { href, title } = node.attrs as { href: string; title: string | null };
+ const domAttrs: Record
= { href };
+ if (title) domAttrs['title'] = title;
+ return ['a', domAttrs, 0];
+ },
+ },
+
+ underline: {
+ parseDOM: [{ tag: 'u' }, { style: 'text-decoration=underline' }],
+ toDOM() {
+ return ['u', 0];
+ },
+ },
+
+ strikethrough: {
+ parseDOM: [{ tag: 's' }, { tag: 'del' }, { style: 'text-decoration=line-through' }],
+ toDOM() {
+ return ['s', 0];
+ },
+ },
+ },
+});
+
+export default schema;
+`
+);
+
+// ─── src/editor-core/plugins/index.ts ────────────────────────────────────────
+write(
+ 'src/editor-core/plugins/index.ts',
+ `import { Plugin } from 'prosemirror-state';
+import { history, undo, redo } from 'prosemirror-history';
+import { keymap } from 'prosemirror-keymap';
+import { baseKeymap, toggleMark } from 'prosemirror-commands';
+import { gapCursor } from 'prosemirror-gapcursor';
+import { inputRules, InputRule } from 'prosemirror-inputrules';
+import schema from '../schema';
+
+/**
+ * Input rules for common markdown-like shorthand:
+ * *text* → em
+ * **text** → strong (checked first — longer pattern takes priority)
+ * \`text\` → code
+ */
+function buildInputRules(): Plugin {
+ const rules: InputRule[] = [
+ new InputRule(/\\*\\*([^*\\s][^*]*)\\*\\*$/, (state, match, start, end) => {
+ const content = match[1] ?? '';
+ if (!content) return null;
+ return state.tr.replaceWith(
+ start,
+ end,
+ schema.text(content, [schema.marks.strong.create()])
+ );
+ }),
+
+ new InputRule(/\\*([^*\\s][^*]*)\\*$/, (state, match, start, end) => {
+ const content = match[1] ?? '';
+ if (!content) return null;
+ return state.tr.replaceWith(
+ start,
+ end,
+ schema.text(content, [schema.marks.em.create()])
+ );
+ }),
+
+ new InputRule(/\`([^\`]+)\`$/, (state, match, start, end) => {
+ const content = match[1] ?? '';
+ if (!content) return null;
+ return state.tr.replaceWith(
+ start,
+ end,
+ schema.text(content, [schema.marks.code.create()])
+ );
+ }),
+ ];
+
+ return inputRules({ rules });
+}
+
+/**
+ * Build the complete plugin array for the editor.
+ * Plugin order matters: earlier plugins have higher key-binding priority.
+ */
+export function buildPlugins(): Plugin[] {
+ return [
+ history(),
+
+ keymap({
+ 'Mod-b': toggleMark(schema.marks.strong),
+ 'Mod-i': toggleMark(schema.marks.em),
+ 'Mod-z': undo,
+ 'Mod-Shift-z': redo,
+ Enter: (state, dispatch) => {
+ if (!dispatch) return false;
+ dispatch(
+ state.tr
+ .replaceSelectionWith(schema.nodes.hard_break.create())
+ .scrollIntoView()
+ );
+ return true;
+ },
+ }),
+
+ keymap(baseKeymap),
+
+ gapCursor(),
+
+ buildInputRules(),
+ ];
+}
+`
+);
+
+// ─── src/editor-core/commands/index.ts ───────────────────────────────────────
+write(
+ 'src/editor-core/commands/index.ts',
+ `import { Command } from 'prosemirror-state';
+import { toggleMark, setBlockType } from 'prosemirror-commands';
+import schema from '../schema';
+
+/** Toggle the em (italic) mark on the current selection. */
+export const toggleItalic: Command = toggleMark(schema.marks.em);
+
+/** Toggle the strong (bold) mark on the current selection. */
+export const toggleBold: Command = toggleMark(schema.marks.strong);
+
+/** Toggle the inline code mark on the current selection. */
+export const toggleCode: Command = toggleMark(schema.marks.code);
+
+/** Toggle the underline mark on the current selection. */
+export const toggleUnderline: Command = toggleMark(schema.marks.underline);
+
+/**
+ * Set the current block to a heading of the given level (1–6).
+ * Returns a Command so callers can bind it to a key or toolbar button.
+ */
+export function setHeading(level: 1 | 2 | 3 | 4 | 5 | 6): Command {
+ return setBlockType(schema.nodes.heading, { level });
+}
+
+/**
+ * Insert a hard line break (\\) at the cursor position.
+ * This breaks the line within the same block without creating a new paragraph.
+ */
+export const insertHardBreak: Command = (state, dispatch) => {
+ if (!dispatch) return false;
+ dispatch(
+ state.tr.replaceSelectionWith(schema.nodes.hard_break.create()).scrollIntoView()
+ );
+ return true;
+};
+`
+);
+
+// ─── src/editor-core/EditorCore.tsx ──────────────────────────────────────────
+write(
+ 'src/editor-core/EditorCore.tsx',
+ `import { useEffect, useRef } from 'react';
+import { EditorState } from 'prosemirror-state';
+import { EditorView } from 'prosemirror-view';
+import schema from './schema';
+import { buildPlugins } from './plugins';
+import styles from './EditorCore.module.css';
+
+interface EditorCoreProps {
+ /** Optional extra class name applied to the editor container. */
+ className?: string;
+}
+
+/**
+ * EditorCore — the ProseMirror editing surface.
+ *
+ * Accessibility contract:
+ * - The outer container div carries role="textbox", aria-multiline, and
+ * aria-label so that assistive technology identifies the editing region.
+ * - The inner ProseMirror contenteditable div does not repeat those
+ * attributes (controlled via the EditorView \`attributes\` option) to
+ * prevent duplicate ARIA exposure.
+ *
+ * Keyboard behaviour (via plugins):
+ * - Mod-b → bold, Mod-i → italic
+ * - Mod-z → undo, Mod-Shift-z → redo
+ * - Enter → insert hard break (inline line break within a block)
+ * - All standard ProseMirror navigation keys
+ */
+export function EditorCore({ className }: EditorCoreProps) {
+ const containerRef = useRef(null);
+
+ useEffect(() => {
+ if (!containerRef.current) return;
+
+ // Minimal valid initial document: one empty title + one empty paragraph.
+ const initialDoc = schema.node('doc', null, [
+ schema.node('title', null, []),
+ schema.node('paragraph', null, []),
+ ]);
+
+ const state = EditorState.create({
+ schema,
+ plugins: buildPlugins(),
+ doc: initialDoc,
+ });
+
+ const view = new EditorView(containerRef.current, {
+ state,
+ // ARIA is handled on the outer container div.
+ // This option prevents accidental duplication on the inner
+ // ProseMirror contenteditable element.
+ attributes: {
+ 'data-editor-content': '',
+ },
+ });
+
+ return () => {
+ view.destroy();
+ };
+ }, []);
+
+ return (
+
+ );
+}
+`
+);
+
+// ─── src/editor-core/EditorCore.module.css ────────────────────────────────────
+write(
+ 'src/editor-core/EditorCore.module.css',
+ `.editor {
+ width: 100%;
+ min-height: 400px;
+ font-family: var(--font-editor);
+ font-size: var(--font-size-editor);
+ line-height: var(--line-height-editor);
+ color: var(--color-text-primary);
+ background-color: var(--color-bg-surface);
+ padding: var(--spacing-xl) var(--spacing-2xl);
+ border-radius: var(--radius-md);
+ border: 1px solid var(--color-border);
+}
+
+/* ProseMirror inner contenteditable div */
+.editor :global(.ProseMirror) {
+ outline: none;
+ min-height: 360px;
+ white-space: pre-wrap;
+}
+
+.editor :global(.ProseMirror-focused) {
+ outline: none;
+}
+
+/* Document title (h1.doc-title) */
+.editor :global(.doc-title) {
+ font-size: 1.75rem;
+ font-weight: 700;
+ line-height: 1.3;
+ color: var(--color-text-primary);
+ margin-bottom: var(--spacing-lg);
+ border-bottom: 1px solid var(--color-border);
+ padding-bottom: var(--spacing-sm);
+}
+
+/* Headings */
+.editor :global(h2) { font-size: 1.5rem; margin-top: var(--spacing-lg); }
+.editor :global(h3) { font-size: 1.25rem; margin-top: var(--spacing-lg); }
+.editor :global(h4) { font-size: 1.125rem; margin-top: var(--spacing-md); }
+
+/* Paragraphs */
+.editor :global(p) {
+ margin-top: var(--spacing-sm);
+}
+
+/* Blockquote */
+.editor :global(blockquote) {
+ border-left: 3px solid var(--color-accent-primary);
+ padding-left: var(--spacing-md);
+ color: var(--color-text-secondary);
+ margin: var(--spacing-md) 0;
+}
+
+/* Code block */
+.editor :global(pre) {
+ background-color: var(--color-bg-secondary);
+ border: 1px solid var(--color-border);
+ border-radius: var(--radius-sm);
+ padding: var(--spacing-md);
+ overflow-x: auto;
+ font-family: 'Courier New', Courier, monospace;
+ font-size: 0.875rem;
+}
+
+/* Inline code */
+.editor :global(code) {
+ background-color: var(--color-bg-secondary);
+ border-radius: var(--radius-sm);
+ padding: 0.1em 0.3em;
+ font-family: 'Courier New', Courier, monospace;
+ font-size: 0.875em;
+}
+
+/* Horizontal rule */
+.editor :global(hr) {
+ border: none;
+ border-top: 1px solid var(--color-border);
+ margin: var(--spacing-lg) 0;
+}
+`
+);
+
+// ─── src/components/Toolbar/Toolbar.tsx ───────────────────────────────────────
+write(
+ 'src/components/Toolbar/Toolbar.tsx',
+ `import styles from './Toolbar.module.css';
+
+interface ToolbarProps {
+ onBold?: () => void;
+ onItalic?: () => void;
+ onUnderline?: () => void;
+ onHeading?: (level: 1 | 2 | 3) => void;
+}
+
+/**
+ * Formatting toolbar.
+ *
+ * Accessibility contract:
+ * - role="toolbar" with aria-label groups buttons as a toolbar landmark.
+ * - Every button has a visible label AND an aria-label for screen readers.
+ * - All buttons are focusable native