feat(client): add EditNoteModal for editing note-based cards

- Create EditNoteModal component that loads note and field values
- Update DeckDetailPage to use EditNoteModal for cards with noteId
- Keep EditCardModal for legacy cards without note association
- Add visual indicator for reversed cards in card list
- Add comprehensive tests for EditNoteModal

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

3 files changed, 1037 insertions, 2 deletions

diff --git a/src/client/components/EditNoteModal.test.tsx b/src/client/components/EditNoteModal.test.tsx
new file mode 100644
index 0000000..61f94bd
--- /dev/null
+++ b/src/client/components/EditNoteModal.test.tsx
@@ -0,0 +1,658 @@
+/**
+ * @vitest-environment jsdom
+ */
+import { cleanup, render, screen, waitFor } from "@testing-library/react";
+import userEvent from "@testing-library/user-event";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import { apiClient } from "../api/client";
+
+vi.mock("../api/client", () => ({
+	apiClient: {
+		getAuthHeader: vi.fn(),
+	},
+	ApiClientError: class ApiClientError extends Error {
+		constructor(
+			message: string,
+			public status: number,
+			public code?: string,
+		) {
+			super(message);
+			this.name = "ApiClientError";
+		}
+	},
+}));
+
+// Import after mock is set up
+import { EditNoteModal } from "./EditNoteModal";
+
+// Mock fetch globally
+const mockFetch = vi.fn();
+global.fetch = mockFetch;
+
+describe("EditNoteModal", () => {
+	const defaultProps = {
+		isOpen: true,
+		deckId: "deck-123",
+		noteId: "note-456",
+		onClose: vi.fn(),
+		onNoteUpdated: vi.fn(),
+	};
+
+	const mockNoteWithFieldValues = {
+		id: "note-456",
+		deckId: "deck-123",
+		noteTypeId: "note-type-1",
+		fieldValues: [
+			{
+				id: "fv-1",
+				noteId: "note-456",
+				noteFieldTypeId: "field-1",
+				value: "Existing front",
+			},
+			{
+				id: "fv-2",
+				noteId: "note-456",
+				noteFieldTypeId: "field-2",
+				value: "Existing back",
+			},
+		],
+	};
+
+	const mockNoteTypeWithFields = {
+		id: "note-type-1",
+		name: "Basic",
+		frontTemplate: "{{Front}}",
+		backTemplate: "{{Back}}",
+		isReversible: false,
+		fields: [
+			{ id: "field-1", name: "Front", order: 0 },
+			{ id: "field-2", name: "Back", order: 1 },
+		],
+	};
+
+	beforeEach(() => {
+		vi.clearAllMocks();
+		vi.mocked(apiClient.getAuthHeader).mockReturnValue({
+			Authorization: "Bearer access-token",
+		});
+	});
+
+	afterEach(() => {
+		cleanup();
+		vi.restoreAllMocks();
+	});
+
+	it("does not render when closed", () => {
+		render(<EditNoteModal {...defaultProps} isOpen={false} />);
+
+		expect(screen.queryByRole("dialog")).toBeNull();
+	});
+
+	it("does not render when noteId is null", () => {
+		render(<EditNoteModal {...defaultProps} noteId={null} />);
+
+		expect(screen.queryByRole("dialog")).toBeNull();
+	});
+
+	it("renders modal when open with noteId", async () => {
+		mockFetch
+			.mockResolvedValueOnce({
+				ok: true,
+				json: async () => ({ note: mockNoteWithFieldValues }),
+			})
+			.mockResolvedValueOnce({
+				ok: true,
+				json: async () => ({ noteType: mockNoteTypeWithFields }),
+			});
+
+		render(<EditNoteModal {...defaultProps} />);
+
+		expect(screen.getByRole("dialog")).toBeDefined();
+		expect(screen.getByRole("heading", { name: "Edit Note" })).toBeDefined();
+
+		// Wait for fields to load
+		await waitFor(() => {
+			expect(screen.getByLabelText("Front")).toBeDefined();
+		});
+	});
+
+	it("fetches note and note type on open", async () => {
+		mockFetch
+			.mockResolvedValueOnce({
+				ok: true,
+				json: async () => ({ note: mockNoteWithFieldValues }),
+			})
+			.mockResolvedValueOnce({
+				ok: true,
+				json: async () => ({ noteType: mockNoteTypeWithFields }),
+			});
+
+		render(<EditNoteModal {...defaultProps} />);
+
+		await waitFor(() => {
+			expect(mockFetch).toHaveBeenCalledWith(
+				"/api/decks/deck-123/notes/note-456",
+				{
+					headers: { Authorization: "Bearer access-token" },
+				},
+			);
+		});
+
+		await waitFor(() => {
+			expect(mockFetch).toHaveBeenCalledWith("/api/note-types/note-type-1", {
+				headers: { Authorization: "Bearer access-token" },
+			});
+		});
+	});
+
+	it("populates form with note field values", async () => {
+		mockFetch
+			.mockResolvedValueOnce({
+				ok: true,
+				json: async () => ({ note: mockNoteWithFieldValues }),
+			})
+			.mockResolvedValueOnce({
+				ok: true,
+				json: async () => ({ noteType: mockNoteTypeWithFields }),
+			});
+
+		render(<EditNoteModal {...defaultProps} />);
+
+		await waitFor(() => {
+			expect(screen.getByLabelText("Front")).toHaveProperty(
+				"value",
+				"Existing front",
+			);
+			expect(screen.getByLabelText("Back")).toHaveProperty(
+				"value",
+				"Existing back",
+			);
+		});
+	});
+
+	it("displays note type name (read-only)", async () => {
+		mockFetch
+			.mockResolvedValueOnce({
+				ok: true,
+				json: async () => ({ note: mockNoteWithFieldValues }),
+			})
+			.mockResolvedValueOnce({
+				ok: true,
+				json: async () => ({ noteType: mockNoteTypeWithFields }),
+			});
+
+		render(<EditNoteModal {...defaultProps} />);
+
+		await waitFor(() => {
+			expect(screen.getByText("Basic")).toBeDefined();
+		});
+	});
+
+	it("disables save button when fields are empty", async () => {
+		const user = userEvent.setup();
+
+		mockFetch
+			.mockResolvedValueOnce({
+				ok: true,
+				json: async () => ({ note: mockNoteWithFieldValues }),
+			})
+			.mockResolvedValueOnce({
+				ok: true,
+				json: async () => ({ noteType: mockNoteTypeWithFields }),
+			});
+
+		render(<EditNoteModal {...defaultProps} />);
+
+		await waitFor(() => {
+			expect(screen.getByLabelText("Front")).toBeDefined();
+		});
+
+		// Clear front field
+		const frontInput = screen.getByLabelText("Front");
+		await user.clear(frontInput);
+
+		const saveButton = screen.getByRole("button", { name: "Save Changes" });
+		expect(saveButton).toHaveProperty("disabled", true);
+	});
+
+	it("enables save button when all fields have values", async () => {
+		mockFetch
+			.mockResolvedValueOnce({
+				ok: true,
+				json: async () => ({ note: mockNoteWithFieldValues }),
+			})
+			.mockResolvedValueOnce({
+				ok: true,
+				json: async () => ({ noteType: mockNoteTypeWithFields }),
+			});
+
+		render(<EditNoteModal {...defaultProps} />);
+
+		await waitFor(() => {
+			expect(screen.getByLabelText("Front")).toBeDefined();
+		});
+
+		const saveButton = screen.getByRole("button", { name: "Save Changes" });
+		expect(saveButton).toHaveProperty("disabled", false);
+	});
+
+	it("calls onClose when Cancel is clicked", async () => {
+		const user = userEvent.setup();
+		const onClose = vi.fn();
+
+		mockFetch
+			.mockResolvedValueOnce({
+				ok: true,
+				json: async () => ({ note: mockNoteWithFieldValues }),
+			})
+			.mockResolvedValueOnce({
+				ok: true,
+				json: async () => ({ noteType: mockNoteTypeWithFields }),
+			});
+
+		render(<EditNoteModal {...defaultProps} onClose={onClose} />);
+
+		await waitFor(() => {
+			expect(screen.getByRole("button", { name: "Cancel" })).toBeDefined();
+		});
+
+		await user.click(screen.getByRole("button", { name: "Cancel" }));
+
+		expect(onClose).toHaveBeenCalledTimes(1);
+	});
+
+	it("calls onClose when clicking outside the modal", async () => {
+		const user = userEvent.setup();
+		const onClose = vi.fn();
+
+		mockFetch
+			.mockResolvedValueOnce({
+				ok: true,
+				json: async () => ({ note: mockNoteWithFieldValues }),
+			})
+			.mockResolvedValueOnce({
+				ok: true,
+				json: async () => ({ noteType: mockNoteTypeWithFields }),
+			});
+
+		render(<EditNoteModal {...defaultProps} onClose={onClose} />);
+
+		await waitFor(() => {
+			expect(screen.getByRole("dialog")).toBeDefined();
+		});
+
+		// Click on the backdrop (the dialog element itself)
+		const dialog = screen.getByRole("dialog");
+		await user.click(dialog);
+
+		expect(onClose).toHaveBeenCalledTimes(1);
+	});
+
+	it("updates note with new field values", async () => {
+		const user = userEvent.setup();
+		const onClose = vi.fn();
+		const onNoteUpdated = vi.fn();
+
+		mockFetch
+			.mockResolvedValueOnce({
+				ok: true,
+				json: async () => ({ note: mockNoteWithFieldValues }),
+			})
+			.mockResolvedValueOnce({
+				ok: true,
+				json: async () => ({ noteType: mockNoteTypeWithFields }),
+			})
+			.mockResolvedValueOnce({
+				ok: true,
+				json: async () => ({ note: mockNoteWithFieldValues }),
+			});
+
+		render(
+			<EditNoteModal
+				isOpen={true}
+				deckId="deck-123"
+				noteId="note-456"
+				onClose={onClose}
+				onNoteUpdated={onNoteUpdated}
+			/>,
+		);
+
+		await waitFor(() => {
+			expect(screen.getByLabelText("Front")).toBeDefined();
+		});
+
+		const frontInput = screen.getByLabelText("Front");
+		await user.clear(frontInput);
+		await user.type(frontInput, "Updated front");
+		await user.click(screen.getByRole("button", { name: "Save Changes" }));
+
+		await waitFor(() => {
+			expect(mockFetch).toHaveBeenCalledWith(
+				"/api/decks/deck-123/notes/note-456",
+				{
+					method: "PUT",
+					headers: {
+						"Content-Type": "application/json",
+						Authorization: "Bearer access-token",
+					},
+					body: JSON.stringify({
+						fields: {
+							"field-1": "Updated front",
+							"field-2": "Existing back",
+						},
+					}),
+				},
+			);
+		});
+
+		expect(onNoteUpdated).toHaveBeenCalledTimes(1);
+		expect(onClose).toHaveBeenCalledTimes(1);
+	});
+
+	it("trims whitespace from field values", async () => {
+		const user = userEvent.setup();
+
+		const noteWithWhitespace = {
+			...mockNoteWithFieldValues,
+			fieldValues: [
+				{
+					id: "fv-1",
+					noteId: "note-456",
+					noteFieldTypeId: "field-1",
+					value: "  Trimmed  ",
+				},
+				{
+					id: "fv-2",
+					noteId: "note-456",
+					noteFieldTypeId: "field-2",
+					value: "  Value  ",
+				},
+			],
+		};
+
+		mockFetch
+			.mockResolvedValueOnce({
+				ok: true,
+				json: async () => ({ note: noteWithWhitespace }),
+			})
+			.mockResolvedValueOnce({
+				ok: true,
+				json: async () => ({ noteType: mockNoteTypeWithFields }),
+			})
+			.mockResolvedValueOnce({
+				ok: true,
+				json: async () => ({ note: noteWithWhitespace }),
+			});
+
+		render(<EditNoteModal {...defaultProps} />);
+
+		await waitFor(() => {
+			expect(screen.getByLabelText("Front")).toBeDefined();
+		});
+
+		await user.click(screen.getByRole("button", { name: "Save Changes" }));
+
+		await waitFor(() => {
+			expect(mockFetch).toHaveBeenCalledWith(
+				"/api/decks/deck-123/notes/note-456",
+				{
+					method: "PUT",
+					headers: {
+						"Content-Type": "application/json",
+						Authorization: "Bearer access-token",
+					},
+					body: JSON.stringify({
+						fields: {
+							"field-1": "Trimmed",
+							"field-2": "Value",
+						},
+					}),
+				},
+			);
+		});
+	});
+
+	it("shows loading state during fetch", async () => {
+		mockFetch.mockImplementationOnce(() => new Promise(() => {})); // Never resolves
+
+		render(<EditNoteModal {...defaultProps} />);
+
+		expect(screen.getByText("Loading note...")).toBeDefined();
+	});
+
+	it("shows loading state during submission", async () => {
+		const user = userEvent.setup();
+
+		mockFetch
+			.mockResolvedValueOnce({
+				ok: true,
+				json: async () => ({ note: mockNoteWithFieldValues }),
+			})
+			.mockResolvedValueOnce({
+				ok: true,
+				json: async () => ({ noteType: mockNoteTypeWithFields }),
+			})
+			.mockImplementationOnce(() => new Promise(() => {})); // Never resolves
+
+		render(<EditNoteModal {...defaultProps} />);
+
+		await waitFor(() => {
+			expect(screen.getByLabelText("Front")).toBeDefined();
+		});
+
+		await user.click(screen.getByRole("button", { name: "Save Changes" }));
+
+		expect(screen.getByRole("button", { name: "Saving..." })).toBeDefined();
+		expect(screen.getByRole("button", { name: "Saving..." })).toHaveProperty(
+			"disabled",
+			true,
+		);
+	});
+
+	it("displays API error message when note fetch fails", async () => {
+		mockFetch.mockResolvedValueOnce({
+			ok: false,
+			status: 404,
+			json: async () => ({ error: "Note not found" }),
+		});
+
+		render(<EditNoteModal {...defaultProps} />);
+
+		await waitFor(() => {
+			expect(screen.getByRole("alert").textContent).toContain("Note not found");
+		});
+	});
+
+	it("displays API error message when note type fetch fails", async () => {
+		mockFetch
+			.mockResolvedValueOnce({
+				ok: true,
+				json: async () => ({ note: mockNoteWithFieldValues }),
+			})
+			.mockResolvedValueOnce({
+				ok: false,
+				status: 404,
+				json: async () => ({ error: "Note type not found" }),
+			});
+
+		render(<EditNoteModal {...defaultProps} />);
+
+		await waitFor(() => {
+			expect(screen.getByRole("alert").textContent).toContain(
+				"Note type not found",
+			);
+		});
+	});
+
+	it("displays API error message when update fails", async () => {
+		const user = userEvent.setup();
+
+		mockFetch
+			.mockResolvedValueOnce({
+				ok: true,
+				json: async () => ({ note: mockNoteWithFieldValues }),
+			})
+			.mockResolvedValueOnce({
+				ok: true,
+				json: async () => ({ noteType: mockNoteTypeWithFields }),
+			})
+			.mockResolvedValueOnce({
+				ok: false,
+				status: 400,
+				json: async () => ({ error: "Failed to update note" }),
+			});
+
+		render(<EditNoteModal {...defaultProps} />);
+
+		await waitFor(() => {
+			expect(screen.getByLabelText("Front")).toBeDefined();
+		});
+
+		await user.click(screen.getByRole("button", { name: "Save Changes" }));
+
+		await waitFor(() => {
+			expect(screen.getByRole("alert").textContent).toContain(
+				"Failed to update note",
+			);
+		});
+	});
+
+	it("displays generic error on unexpected failure", async () => {
+		mockFetch.mockRejectedValueOnce(new Error("Network error"));
+
+		render(<EditNoteModal {...defaultProps} />);
+
+		await waitFor(() => {
+			expect(screen.getByRole("alert").textContent).toContain(
+				"Failed to load note. Please try again.",
+			);
+		});
+	});
+
+	it("displays error when not authenticated", async () => {
+		vi.mocked(apiClient.getAuthHeader).mockReturnValue(undefined);
+
+		render(<EditNoteModal {...defaultProps} />);
+
+		await waitFor(() => {
+			expect(screen.getByRole("alert").textContent).toContain(
+				"Not authenticated",
+			);
+		});
+	});
+
+	it("resets form when modal is closed and reopened with different noteId", async () => {
+		const onClose = vi.fn();
+
+		mockFetch
+			.mockResolvedValueOnce({
+				ok: true,
+				json: async () => ({ note: mockNoteWithFieldValues }),
+			})
+			.mockResolvedValueOnce({
+				ok: true,
+				json: async () => ({ noteType: mockNoteTypeWithFields }),
+			});
+
+		const { rerender } = render(
+			<EditNoteModal
+				isOpen={true}
+				deckId="deck-123"
+				noteId="note-456"
+				onClose={onClose}
+				onNoteUpdated={vi.fn()}
+			/>,
+		);
+
+		await waitFor(() => {
+			expect(screen.getByLabelText("Front")).toHaveProperty(
+				"value",
+				"Existing front",
+			);
+		});
+
+		// Close modal
+		rerender(
+			<EditNoteModal
+				isOpen={false}
+				deckId="deck-123"
+				noteId={null}
+				onClose={onClose}
+				onNoteUpdated={vi.fn()}
+			/>,
+		);
+
+		// Setup new note data
+		const newNoteWithFieldValues = {
+			id: "note-789",
+			deckId: "deck-123",
+			noteTypeId: "note-type-1",
+			fieldValues: [
+				{
+					id: "fv-3",
+					noteId: "note-789",
+					noteFieldTypeId: "field-1",
+					value: "New front",
+				},
+				{
+					id: "fv-4",
+					noteId: "note-789",
+					noteFieldTypeId: "field-2",
+					value: "New back",
+				},
+			],
+		};
+
+		mockFetch
+			.mockResolvedValueOnce({
+				ok: true,
+				json: async () => ({ note: newNoteWithFieldValues }),
+			})
+			.mockResolvedValueOnce({
+				ok: true,
+				json: async () => ({ noteType: mockNoteTypeWithFields }),
+			});
+
+		// Reopen with different noteId
+		rerender(
+			<EditNoteModal
+				isOpen={true}
+				deckId="deck-123"
+				noteId="note-789"
+				onClose={onClose}
+				onNoteUpdated={vi.fn()}
+			/>,
+		);
+
+		await waitFor(() => {
+			expect(screen.getByLabelText("Front")).toHaveProperty(
+				"value",
+				"New front",
+			);
+			expect(screen.getByLabelText("Back")).toHaveProperty("value", "New back");
+		});
+	});
+
+	it("shows reversed indicator for reversible note type", async () => {
+		const reversibleNoteType = {
+			...mockNoteTypeWithFields,
+			isReversible: true,
+		};
+
+		mockFetch
+			.mockResolvedValueOnce({
+				ok: true,
+				json: async () => ({ note: mockNoteWithFieldValues }),
+			})
+			.mockResolvedValueOnce({
+				ok: true,
+				json: async () => ({ noteType: reversibleNoteType }),
+			});
+
+		render(<EditNoteModal {...defaultProps} />);
+
+		await waitFor(() => {
+			expect(screen.getByText("Basic (reversed)")).toBeDefined();
+		});
+	});
+});
diff --git a/src/client/components/EditNoteModal.tsx b/src/client/components/EditNoteModal.tsx
new file mode 100644
index 0000000..5bd864d
--- /dev/null
+++ b/src/client/components/EditNoteModal.tsx
@@ -0,0 +1,352 @@
+import { faSpinner } from "@fortawesome/free-solid-svg-icons";
+import { FontAwesomeIcon } from "@fortawesome/react-fontawesome";
+import { type FormEvent, useCallback, useEffect, useState } from "react";
+import { ApiClientError, apiClient } from "../api";
+
+interface NoteField {
+	id: string;
+	name: string;
+	order: number;
+}
+
+interface NoteType {
+	id: string;
+	name: string;
+	frontTemplate: string;
+	backTemplate: string;
+	isReversible: boolean;
+	fields: NoteField[];
+}
+
+interface NoteFieldValue {
+	id: string;
+	noteId: string;
+	noteFieldTypeId: string;
+	value: string;
+}
+
+interface NoteWithFieldValues {
+	id: string;
+	deckId: string;
+	noteTypeId: string;
+	fieldValues: NoteFieldValue[];
+}
+
+interface EditNoteModalProps {
+	isOpen: boolean;
+	deckId: string;
+	noteId: string | null;
+	onClose: () => void;
+	onNoteUpdated: () => void;
+}
+
+export function EditNoteModal({
+	isOpen,
+	deckId,
+	noteId,
+	onClose,
+	onNoteUpdated,
+}: EditNoteModalProps) {
+	const [note, setNote] = useState<NoteWithFieldValues | null>(null);
+	const [noteType, setNoteType] = useState<NoteType | null>(null);
+	const [fieldValues, setFieldValues] = useState<Record<string, string>>({});
+	const [error, setError] = useState<string | null>(null);
+	const [isLoadingNote, setIsLoadingNote] = useState(false);
+	const [isLoadingNoteType, setIsLoadingNoteType] = useState(false);
+	const [isSubmitting, setIsSubmitting] = useState(false);
+
+	const fetchNoteTypeDetails = useCallback(async (noteTypeId: string) => {
+		setIsLoadingNoteType(true);
+		setError(null);
+
+		try {
+			const authHeader = apiClient.getAuthHeader();
+			if (!authHeader) {
+				throw new ApiClientError("Not authenticated", 401);
+			}
+
+			const res = await fetch(`/api/note-types/${noteTypeId}`, {
+				headers: authHeader,
+			});
+
+			if (!res.ok) {
+				const errorBody = await res.json().catch(() => ({}));
+				throw new ApiClientError(
+					(errorBody as { error?: string }).error ||
+						`Request failed with status ${res.status}`,
+					res.status,
+				);
+			}
+
+			const data = await res.json();
+			setNoteType(data.noteType);
+		} catch (err) {
+			if (err instanceof ApiClientError) {
+				setError(err.message);
+			} else {
+				setError("Failed to load note type details. Please try again.");
+			}
+		} finally {
+			setIsLoadingNoteType(false);
+		}
+	}, []);
+
+	const fetchNote = useCallback(async () => {
+		if (!noteId) return;
+
+		setIsLoadingNote(true);
+		setError(null);
+
+		try {
+			const authHeader = apiClient.getAuthHeader();
+			if (!authHeader) {
+				throw new ApiClientError("Not authenticated", 401);
+			}
+
+			const res = await fetch(`/api/decks/${deckId}/notes/${noteId}`, {
+				headers: authHeader,
+			});
+
+			if (!res.ok) {
+				const errorBody = await res.json().catch(() => ({}));
+				throw new ApiClientError(
+					(errorBody as { error?: string }).error ||
+						`Request failed with status ${res.status}`,
+					res.status,
+				);
+			}
+
+			const data = await res.json();
+			setNote(data.note);
+
+			// Initialize field values from note
+			const initialValues: Record<string, string> = {};
+			for (const fv of data.note.fieldValues) {
+				initialValues[fv.noteFieldTypeId] = fv.value;
+			}
+			setFieldValues(initialValues);
+
+			// Fetch note type details
+			await fetchNoteTypeDetails(data.note.noteTypeId);
+		} catch (err) {
+			if (err instanceof ApiClientError) {
+				setError(err.message);
+			} else {
+				setError("Failed to load note. Please try again.");
+			}
+		} finally {
+			setIsLoadingNote(false);
+		}
+	}, [noteId, deckId, fetchNoteTypeDetails]);
+
+	useEffect(() => {
+		if (isOpen && noteId) {
+			fetchNote();
+		}
+	}, [isOpen, noteId, fetchNote]);
+
+	const resetForm = () => {
+		setNote(null);
+		setNoteType(null);
+		setFieldValues({});
+		setError(null);
+	};
+
+	const handleClose = () => {
+		resetForm();
+		onClose();
+	};
+
+	const handleFieldChange = (fieldId: string, value: string) => {
+		setFieldValues((prev) => ({
+			...prev,
+			[fieldId]: value,
+		}));
+	};
+
+	const handleSubmit = async (e: FormEvent) => {
+		e.preventDefault();
+		setError(null);
+
+		if (!note) {
+			setError("Note data is not loaded.");
+			return;
+		}
+
+		setIsSubmitting(true);
+
+		try {
+			const authHeader = apiClient.getAuthHeader();
+			if (!authHeader) {
+				throw new ApiClientError("Not authenticated", 401);
+			}
+
+			// Trim all field values
+			const trimmedFields: Record<string, string> = {};
+			for (const [fieldId, value] of Object.entries(fieldValues)) {
+				trimmedFields[fieldId] = value.trim();
+			}
+
+			const res = await fetch(`/api/decks/${deckId}/notes/${note.id}`, {
+				method: "PUT",
+				headers: {
+					"Content-Type": "application/json",
+					...authHeader,
+				},
+				body: JSON.stringify({
+					fields: trimmedFields,
+				}),
+			});
+
+			if (!res.ok) {
+				const errorBody = await res.json().catch(() => ({}));
+				throw new ApiClientError(
+					(errorBody as { error?: string }).error ||
+						`Request failed with status ${res.status}`,
+					res.status,
+				);
+			}
+
+			onNoteUpdated();
+			handleClose();
+		} catch (err) {
+			if (err instanceof ApiClientError) {
+				setError(err.message);
+			} else {
+				setError("Failed to update note. Please try again.");
+			}
+		} finally {
+			setIsSubmitting(false);
+		}
+	};
+
+	if (!isOpen || !noteId) {
+		return null;
+	}
+
+	// Check if all required fields have values
+	const isFormValid =
+		noteType &&
+		noteType.fields.length > 0 &&
+		noteType.fields.every((field) => fieldValues[field.id]?.trim());
+
+	const isLoading = isLoadingNote || isLoadingNoteType;
+
+	return (
+		<div
+			role="dialog"
+			aria-modal="true"
+			aria-labelledby="edit-note-title"
+			className="fixed inset-0 bg-ink/40 backdrop-blur-sm flex items-center justify-center z-50 p-4 animate-fade-in"
+			onClick={(e) => {
+				if (e.target === e.currentTarget) {
+					handleClose();
+				}
+			}}
+			onKeyDown={(e) => {
+				if (e.key === "Escape") {
+					handleClose();
+				}
+			}}
+		>
+			<div className="bg-white rounded-2xl shadow-xl w-full max-w-lg animate-scale-in">
+				<div className="p-6">
+					<h2
+						id="edit-note-title"
+						className="font-display text-xl font-medium text-ink mb-6"
+					>
+						Edit Note
+					</h2>
+
+					<form onSubmit={handleSubmit} className="space-y-4">
+						{error && (
+							<div
+								role="alert"
+								className="bg-error/5 text-error text-sm px-4 py-3 rounded-lg border border-error/20"
+							>
+								{error}
+							</div>
+						)}
+
+						{/* Loading indicator */}
+						{isLoading && (
+							<div className="flex items-center gap-2 text-muted text-sm py-4">
+								<FontAwesomeIcon
+									icon={faSpinner}
+									className="h-4 w-4 animate-spin"
+									aria-hidden="true"
+								/>
+								Loading note...
+							</div>
+						)}
+
+						{/* Note Type Display (read-only) */}
+						{noteType && !isLoading && (
+							<div>
+								<span className="block text-sm font-medium text-slate mb-1.5">
+									Note Type
+								</span>
+								<div className="px-4 py-2.5 bg-ivory border border-border rounded-lg text-muted">
+									{noteType.name}
+									{noteType.isReversible ? " (reversed)" : ""}
+								</div>
+							</div>
+						)}
+
+						{/* Dynamic Field Inputs */}
+						{noteType &&
+							!isLoading &&
+							(noteType.fields.length === 0 ? (
+								<div className="text-muted text-sm py-2">
+									This note type has no fields.
+								</div>
+							) : (
+								noteType.fields
+									.sort((a, b) => a.order - b.order)
+									.map((field) => (
+										<div key={field.id}>
+											<label
+												htmlFor={`field-${field.id}`}
+												className="block text-sm font-medium text-slate mb-1.5"
+											>
+												{field.name}
+											</label>
+											<textarea
+												id={`field-${field.id}`}
+												value={fieldValues[field.id] || ""}
+												onChange={(e) =>
+													handleFieldChange(field.id, e.target.value)
+												}
+												required
+												disabled={isSubmitting}
+												rows={3}
+												placeholder={`Enter ${field.name.toLowerCase()}`}
+												className="w-full px-4 py-2.5 bg-ivory border border-border rounded-lg text-slate placeholder-muted transition-all duration-200 hover:border-muted focus:border-primary focus:ring-2 focus:ring-primary/10 disabled:opacity-50 disabled:cursor-not-allowed resize-none"
+											/>
+										</div>
+									))
+							))}
+
+						<div className="flex gap-3 justify-end pt-2">
+							<button
+								type="button"
+								onClick={handleClose}
+								disabled={isSubmitting}
+								className="px-4 py-2 text-slate hover:bg-ivory rounded-lg transition-colors disabled:opacity-50"
+							>
+								Cancel
+							</button>
+							<button
+								type="submit"
+								disabled={isSubmitting || !isFormValid || isLoading}
+								className="px-4 py-2 bg-primary hover:bg-primary-dark text-white font-medium rounded-lg transition-all duration-200 disabled:opacity-50 disabled:cursor-not-allowed"
+							>
+								{isSubmitting ? "Saving..." : "Save Changes"}
+							</button>
+						</div>
+					</form>
+				</div>
+			</div>
+		</div>
+	);
+}
diff --git a/src/client/pages/DeckDetailPage.tsx b/src/client/pages/DeckDetailPage.tsx
index 9a158f6..a06fcc7 100644
--- a/src/client/pages/DeckDetailPage.tsx
+++ b/src/client/pages/DeckDetailPage.tsx
@@ -14,10 +14,13 @@ import { ApiClientError, apiClient } from "../api";
 import { CreateNoteModal } from "../components/CreateNoteModal";
 import { DeleteCardModal } from "../components/DeleteCardModal";
 import { EditCardModal } from "../components/EditCardModal";
+import { EditNoteModal } from "../components/EditNoteModal";
 
 interface Card {
 	id: string;
 	deckId: string;
+	noteId: string | null;
+	isReversed: boolean | null;
 	front: string;
 	back: string;
 	state: number;
@@ -56,6 +59,7 @@ export function DeckDetailPage() {
 	const [error, setError] = useState<string | null>(null);
 	const [isCreateModalOpen, setIsCreateModalOpen] = useState(false);
 	const [editingCard, setEditingCard] = useState<Card | null>(null);
+	const [editingNoteId, setEditingNoteId] = useState<string | null>(null);
 	const [deletingCard, setDeletingCard] = useState<Card | null>(null);
 
 	const fetchDeck = useCallback(async () => {
@@ -311,6 +315,11 @@ export function DeckDetailPage() {
 													>
 														{CardStateLabels[card.state] || "Unknown"}
 													</span>
+													{card.isReversed && (
+														<span className="px-2 py-0.5 rounded-full font-medium bg-slate/10 text-slate">
+															Reversed
+														</span>
+													)}
 													<span className="text-muted">
 														{card.reps} reviews
 													</span>
@@ -326,9 +335,15 @@ export function DeckDetailPage() {
 											<div className="flex items-center gap-1 shrink-0">
 												<button
 													type="button"
-													onClick={() => setEditingCard(card)}
+													onClick={() => {
+														if (card.noteId) {
+															setEditingNoteId(card.noteId);
+														} else {
+															setEditingCard(card);
+														}
+													}}
 													className="p-2 text-muted hover:text-slate hover:bg-ivory rounded-lg transition-colors"
-													title="Edit card"
+													title={card.noteId ? "Edit note" : "Edit card"}
 												>
 													<FontAwesomeIcon
 														icon={faPen}
@@ -379,6 +394,16 @@ export function DeckDetailPage() {
 			)}
 
 			{deckId && (
+				<EditNoteModal
+					isOpen={editingNoteId !== null}
+					deckId={deckId}
+					noteId={editingNoteId}
+					onClose={() => setEditingNoteId(null)}
+					onNoteUpdated={fetchCards}
+				/>
+			)}
+
+			{deckId && (
 				<DeleteCardModal
 					isOpen={deletingCard !== null}
 					deckId={deckId}