diff --git a/src/hooks/__tests__/useCardSettings.test.ts b/src/hooks/__tests__/useCardSettings.test.ts
new file mode 100644
index 0000000..426a513
--- /dev/null
+++ b/src/hooks/__tests__/useCardSettings.test.ts
@@ -0,0 +1,166 @@
+// @vitest-environment jsdom
+import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";
+import { renderHook, act } from "@testing-library/react";
+import { useCardSettings } from "../useCardSettings";
+import { DEFAULT_CARD_LAYOUT } from "@/lib/types";
+import { DEFAULT_DISPLAY_OPTIONS } from "@/lib/cardSettings";
+import * as cardSettingsLib from "@/lib/cardSettings";
+
+describe("useCardSettings", () => {
+  beforeEach(() => {
+    window.localStorage.clear();
+    vi.clearAllMocks();
+  });
+
+  afterEach(() => {
+    window.localStorage.clear();
+    vi.restoreAllMocks();
+  });
+
+  it("should initialize with default settings when localStorage is empty", () => {
+    const { result } = renderHook(() => useCardSettings(false));
+
+    expect(result.current.layout).toEqual(DEFAULT_CARD_LAYOUT);
+    expect(result.current.displayOptions).toEqual(DEFAULT_DISPLAY_OPTIONS);
+  });
+
+  it("should load settings from localStorage on initial render if available", () => {
+    const customOptions = { ...DEFAULT_DISPLAY_OPTIONS, showAvatar: false };
+    window.localStorage.setItem("card-display-options", JSON.stringify(customOptions));
+
+    const { result } = renderHook(() => useCardSettings(false));
+
+    expect(result.current.displayOptions.showAvatar).toBe(false);
+  });
+
+  it("should hydrate when mounted becomes true and not change state if options are identical", () => {
+    // Set exact default options to local storage so JSON.stringify(prev) === JSON.stringify(stored)
+    window.localStorage.setItem("card-display-options", JSON.stringify(DEFAULT_DISPLAY_OPTIONS));
+    window.localStorage.setItem("card-layout", JSON.stringify(DEFAULT_CARD_LAYOUT));
+
+    const { result, rerender } = renderHook(({ mounted }) => useCardSettings(mounted), {
+      initialProps: { mounted: false }
+    });
+
+    const initialLayout = result.current.layout;
+    const initialOptions = result.current.displayOptions;
+
+    // Rerender as mounted
+    rerender({ mounted: true });
+
+    // Ensure state references didn't change because values were identical
+    expect(result.current.layout).toBe(initialLayout);
+    expect(result.current.displayOptions).toBe(initialOptions);
+  });
+
+  it("should hydrate when mounted becomes true and change state if options differ", () => {
+    // Change options so they differ from initial state to hit true branch of ternary
+    const customOptions = { ...DEFAULT_DISPLAY_OPTIONS, showAvatar: false };
+    const customLayout = { blocks: [{ id: "profile", visible: false, column: "full" }] };
+
+    const { result, rerender } = renderHook(({ mounted }) => useCardSettings(mounted), {
+      initialProps: { mounted: false }
+    });
+
+    // Mock loadCardSettings to return new values during effect execution
+    vi.spyOn(cardSettingsLib, 'loadCardSettings').mockReturnValueOnce({
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      layout: customLayout as any,
+      options: customOptions
+    });
+
+    rerender({ mounted: true });
+
+    expect(result.current.displayOptions.showAvatar).toBe(false);
+    expect(result.current.layout).toEqual(customLayout);
+  });
+
+  it("should not hydrate if already hydrated", () => {
+    // Spy on setItem to see if saveCardSettings was called again
+    const saveCardSettingsSpy = vi.spyOn(cardSettingsLib, 'saveCardSettings');
+
+    const { rerender } = renderHook(({ mounted }) => useCardSettings(mounted), {
+      initialProps: { mounted: true }
+    });
+
+    // Initial mount hydration complete
+    expect(saveCardSettingsSpy).toHaveBeenCalledTimes(1);
+
+    // Rerender again with mounted: true
+    rerender({ mounted: true });
+
+    // It should not trigger hydration logic again, but saveCardSettings will trigger
+    // because of useEffect dependencies unless we verify state setter didn't fire again.
+    // Testing the early return in the first useEffect:
+    const loadCardSettingsSpy = vi.spyOn(cardSettingsLib, 'loadCardSettings');
+    rerender({ mounted: true });
+
+    // The load shouldn't be called again since isHydrated is true
+    expect(loadCardSettingsSpy).toHaveBeenCalledTimes(0);
+  });
+
+
+  it("should update display options when toggleDisplayOption is called", () => {
+    const { result } = renderHook(() => useCardSettings(true));
+
+    expect(result.current.displayOptions.showAvatar).toBe(true);
+
+    act(() => {
+      result.current.toggleDisplayOption("showAvatar");
+    });
+
+    expect(result.current.displayOptions.showAvatar).toBe(false);
+
+    // Verify it was saved to storage
+    const savedOptions = JSON.parse(window.localStorage.getItem("card-display-options") || "{}");
+    expect(savedOptions.showAvatar).toBe(false);
+  });
+
+  it("should update layout when toggleMainBlockVisibility is called", () => {
+    const { result } = renderHook(() => useCardSettings(true));
+
+    const profileBlock = result.current.layout.blocks.find(b => b.id === "profile");
+    expect(profileBlock?.visible).toBe(true);
+
+    act(() => {
+      result.current.toggleMainBlockVisibility("profile");
+    });
+
+    const updatedProfileBlock = result.current.layout.blocks.find(b => b.id === "profile");
+    expect(updatedProfileBlock?.visible).toBe(false);
+
+    // Verify it was saved to storage
+    const savedLayout = JSON.parse(window.localStorage.getItem("card-layout") || "{}");
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    const savedProfileBlock = savedLayout.blocks.find((b: any) => b.id === "profile");
+    expect(savedProfileBlock.visible).toBe(false);
+  });
+
+  it("should return correct visibility using isBlockVisible", () => {
+    const { result } = renderHook(() => useCardSettings(true));
+
+    expect(result.current.isBlockVisible("profile")).toBe(true);
+
+    act(() => {
+      result.current.toggleMainBlockVisibility("profile");
+    });
+
+    expect(result.current.isBlockVisible("profile")).toBe(false);
+    // @ts-expect-error Testing invalid id
+    expect(result.current.isBlockVisible("invalid-id")).toBe(false);
+  });
+
+  it("should not save settings to localStorage if not hydrated", () => {
+    // Spy on setItem
+    const setItemSpy = vi.spyOn(Storage.prototype, 'setItem');
+
+    const { result } = renderHook(() => useCardSettings(false));
+
+    act(() => {
+      result.current.toggleDisplayOption("showAvatar");
+    });
+
+    // It shouldn't have setItem because it's not mounted and hydrated
+    expect(setItemSpy).not.toHaveBeenCalled();
+  });
+});
diff --git a/src/hooks/useCardSettings.ts b/src/hooks/useCardSettings.ts
index c54dbc3..db3e777 100644
--- a/src/hooks/useCardSettings.ts
+++ b/src/hooks/useCardSettings.ts
@@ -26,7 +26,6 @@ export function useCardSettings(mounted: boolean) {
     
     // eslint-disable-next-line react-hooks/set-state-in-effect
     setLayout((prev) => JSON.stringify(prev) !== JSON.stringify(storedLayout) ? storedLayout : prev);
-    // eslint-disable-next-line react-hooks/set-state-in-effect
     setDisplayOptions((prev) => JSON.stringify(prev) !== JSON.stringify(storedOptions) ? storedOptions : prev);
     
     setIsHydrated(true);