diff --git a/README.md b/README.md
index 903c876f9..a64be6840 100644
--- a/README.md
+++ b/README.md
@@ -33,4 +33,4 @@ Implement a simple [TODO app](https://mate-academy.github.io/react_todo-app/) th
 - Implement a solution following the [React task guidelines](https://github.com/mate-academy/react_task-guideline#react-tasks-guideline).
 - Use the [React TypeScript cheat sheet](https://mate-academy.github.io/fe-program/js/extra/react-typescript).
 - Open another terminal and run tests with `npm test` to ensure your solution is correct.
-- Replace `<your_account>` with your GitHub username in the [DEMO LINK](https://<your_account>.github.io/react_todo-app/) and add it to the PR description.
+- Replace `<your_account>` with your GitHub username in the [DEMO LINK](https://Nazarin565.github.io/react_todo-app/) and add it to the PR description.
diff --git a/src/App.tsx b/src/App.tsx
index a399287bd..b9aac861a 100644
--- a/src/App.tsx
+++ b/src/App.tsx
@@ -1,156 +1,23 @@
 /* eslint-disable jsx-a11y/control-has-associated-label */
 import React from 'react';
+import { TodoList } from './components/TodoList';
+import { Header } from './components/Header';
+import { Footer } from './components/Footer';
+import { useGlobalState } from './Store';
 
 export const App: React.FC = () => {
+  const { todos } = useGlobalState();
+
   return (
     <div className="todoapp">
       <h1 className="todoapp__title">todos</h1>
 
       <div className="todoapp__content">
-        <header className="todoapp__header">
-          {/* this button should have `active` class only if all todos are completed */}
-          <button
-            type="button"
-            className="todoapp__toggle-all active"
-            data-cy="ToggleAllButton"
-          />
-
-          {/* Add a todo on form submit */}
-          <form>
-            <input
-              data-cy="NewTodoField"
-              type="text"
-              className="todoapp__new-todo"
-              placeholder="What needs to be done?"
-            />
-          </form>
-        </header>
-
-        <section className="todoapp__main" data-cy="TodoList">
-          {/* This is a completed todo */}
-          <div data-cy="Todo" className="todo completed">
-            <label className="todo__status-label">
-              <input
-                data-cy="TodoStatus"
-                type="checkbox"
-                className="todo__status"
-                checked
-              />
-            </label>
-
-            <span data-cy="TodoTitle" className="todo__title">
-              Completed Todo
-            </span>
-
-            {/* Remove button appears only on hover */}
-            <button type="button" className="todo__remove" data-cy="TodoDelete">
-              ×
-            </button>
-          </div>
-
-          {/* This todo is an active todo */}
-          <div data-cy="Todo" className="todo">
-            <label className="todo__status-label">
-              <input
-                data-cy="TodoStatus"
-                type="checkbox"
-                className="todo__status"
-              />
-            </label>
-
-            <span data-cy="TodoTitle" className="todo__title">
-              Not Completed Todo
-            </span>
-
-            <button type="button" className="todo__remove" data-cy="TodoDelete">
-              ×
-            </button>
-          </div>
-
-          {/* This todo is being edited */}
-          <div data-cy="Todo" className="todo">
-            <label className="todo__status-label">
-              <input
-                data-cy="TodoStatus"
-                type="checkbox"
-                className="todo__status"
-              />
-            </label>
-
-            {/* This form is shown instead of the title and remove button */}
-            <form>
-              <input
-                data-cy="TodoTitleField"
-                type="text"
-                className="todo__title-field"
-                placeholder="Empty todo will be deleted"
-                value="Todo is being edited now"
-              />
-            </form>
-          </div>
-
-          {/* This todo is in loadind state */}
-          <div data-cy="Todo" className="todo">
-            <label className="todo__status-label">
-              <input
-                data-cy="TodoStatus"
-                type="checkbox"
-                className="todo__status"
-              />
-            </label>
-
-            <span data-cy="TodoTitle" className="todo__title">
-              Todo is being saved now
-            </span>
-
-            <button type="button" className="todo__remove" data-cy="TodoDelete">
-              ×
-            </button>
-          </div>
-        </section>
-
-        {/* Hide the footer if there are no todos */}
-        <footer className="todoapp__footer" data-cy="Footer">
-          <span className="todo-count" data-cy="TodosCounter">
-            3 items left
-          </span>
-
-          {/* Active link should have the 'selected' class */}
-          <nav className="filter" data-cy="Filter">
-            <a
-              href="#/"
-              className="filter__link selected"
-              data-cy="FilterLinkAll"
-            >
-              All
-            </a>
-
-            <a
-              href="#/active"
-              className="filter__link"
-              data-cy="FilterLinkActive"
-            >
-              Active
-            </a>
+        <Header />
 
-            <a
-              href="#/completed"
-              className="filter__link"
-              data-cy="FilterLinkCompleted"
-            >
-              Completed
-            </a>
-          </nav>
+        {!!todos.length && <TodoList />}
 
-          {/* this button should be disabled if there are no completed todos */}
-          <button
-            type="button"
-            className="todoapp__clear-completed"
-            data-cy="ClearCompletedButton"
-          >
-            Clear completed
-          </button>
-        </footer>
+        {!!todos.length && <Footer />}
       </div>
     </div>
   );
diff --git a/src/Store.tsx b/src/Store.tsx
new file mode 100644
index 000000000..fc6df0a94
--- /dev/null
+++ b/src/Store.tsx
@@ -0,0 +1,125 @@
+import React, { useEffect, useReducer } from 'react';
+import { SelectedFilter } from './types/SelectedFilter';
+import { State } from './types/State';
+import { Action } from './types/Action';
+import { loadFromLocalStorage } from './utils/LocaleStorage';
+
+const initialState: State = {
+  todos: [],
+  query: '',
+  filter: SelectedFilter.ALL,
+  editingTodoId: null,
+  currentTitle: '',
+};
+
+function reducer(state: State, action: Action): State {
+  switch (action.type) {
+    case 'toogleAllChecked':
+      const checked = state.todos.every(todo => todo.completed);
+
+      return {
+        ...state,
+        todos: [...state.todos.map(todo => ({ ...todo, completed: !checked }))],
+      };
+
+    case 'addTodo':
+      return {
+        ...state,
+        todos: [...state.todos, action.payload],
+      };
+
+    case 'setQuery':
+      return {
+        ...state,
+        query: action.payload,
+      };
+
+    case 'deleteTodo':
+      return {
+        ...state,
+        todos: [...state.todos.filter(todo => todo.id !== action.payload)],
+      };
+
+    case 'massDelete':
+      return {
+        ...state,
+        todos: [
+          ...state.todos.filter(todo => !action.payload.includes(todo.id)),
+        ],
+      };
+
+    case 'changeCheckbox':
+      return {
+        ...state,
+        todos: [
+          ...state.todos.map(todo =>
+            todo.id === action.payload
+              ? { ...todo, completed: !todo.completed }
+              : todo,
+          ),
+        ],
+      };
+
+    case 'updateTodo':
+      return {
+        ...state,
+        todos: [
+          ...state.todos.map(todo => {
+            return todo.id === action.payload.id
+              ? { ...todo, title: action.payload.title }
+              : todo;
+          }),
+        ],
+      };
+
+    case 'setCurrentTitle':
+      return {
+        ...state,
+        currentTitle: action.payload,
+      };
+
+    case 'setEditingTodoId':
+      return {
+        ...state,
+        editingTodoId: action.payload,
+      };
+
+    case 'setFilter':
+      return {
+        ...state,
+        filter: action.payload,
+      };
+  }
+}
+
+export const StateContext = React.createContext<State>(initialState);
+export const DispatchContext = React.createContext<React.Dispatch<Action>>(
+  () => {},
+);
+
+type Props = {
+  children: React.ReactNode;
+};
+
+export const GlobalStateProvider: React.FC<Props> = ({ children }) => {
+  const [state, dispatch] = useReducer(reducer, initialState, () => ({
+    todos: loadFromLocalStorage('todos'),
+    query: '',
+    filter: SelectedFilter.ALL,
+    editingTodoId: null,
+    currentTitle: '',
+  }));
+
+  useEffect(() => {
+    localStorage.setItem('todos', JSON.stringify(state.todos));
+  }, [state.todos]);
+
+  return (
+    <DispatchContext.Provider value={dispatch}>
+      <StateContext.Provider value={state}>{children}</StateContext.Provider>
+    </DispatchContext.Provider>
+  );
+};
+
+export const useGlobalState = () => React.useContext(StateContext);
+export const useGlobalDispatch = () => React.useContext(DispatchContext);
diff --git a/src/components/EditForm.tsx b/src/components/EditForm.tsx
new file mode 100644
index 000000000..950a1bd05
--- /dev/null
+++ b/src/components/EditForm.tsx
@@ -0,0 +1,72 @@
+import { useEffect, useRef } from 'react';
+import { useGlobalDispatch, useGlobalState } from '../Store';
+import { Todo } from '../types/Todo';
+
+type Props = {
+  newTodo: Todo;
+};
+
+export const EditForm: React.FC<Props> = ({
+  newTodo: { id, title, completed },
+}) => {
+  const { currentTitle, editingTodoId } = useGlobalState();
+  const dispatch = useGlobalDispatch();
+
+  const editRef = useRef<HTMLInputElement>(null);
+
+  useEffect(() => {
+    if (editRef.current && editingTodoId) {
+      editRef.current.focus();
+    }
+  }, [editRef, editingTodoId]);
+
+  const handleUpdateTitle = (newTodo: Todo) => {
+    const trimmedTitle = currentTitle.trim();
+
+    if (!trimmedTitle) {
+      dispatch({ type: 'deleteTodo', payload: newTodo.id });
+    } else {
+      dispatch({
+        type: 'updateTodo',
+        payload: { ...newTodo, title: trimmedTitle },
+      });
+    }
+
+    dispatch({ type: 'setEditingTodoId', payload: null });
+  };
+
+  const handleUpdateTitleSubmit = (event: React.FormEvent, newTodo: Todo) => {
+    event.preventDefault();
+    handleUpdateTitle(newTodo);
+  };
+
+  const handleChange = (event: React.ChangeEvent<HTMLInputElement>) =>
+    dispatch({ type: 'setCurrentTitle', payload: event.target.value });
+
+  const handleKeyUp = (event: React.KeyboardEvent<HTMLInputElement>) => {
+    if (event.key === 'Escape') {
+      dispatch({ type: 'setCurrentTitle', payload: title });
+      dispatch({ type: 'setEditingTodoId', payload: null });
+    }
+  };
+
+  return (
+    <form
+      onSubmit={event =>
+        handleUpdateTitleSubmit(event, { id, title, completed })
+      }
+    >
+      <input
+        ref={editRef}
+        data-cy="TodoTitleField"
+        type="text"
+        className="todo__title-field"
+        placeholder="Empty todo will be deleted"
+        value={currentTitle}
+        onBlur={() => handleUpdateTitle({ id, title, completed })}
+        onChange={handleChange}
+        onKeyUp={handleKeyUp}
+      />
+    </form>
+  );
+};
diff --git a/src/components/FilterOption.tsx b/src/components/FilterOption.tsx
new file mode 100644
index 000000000..5c0a4dd8d
--- /dev/null
+++ b/src/components/FilterOption.tsx
@@ -0,0 +1,28 @@
+import cn from 'classnames';
+import { FilteredOptions } from '../types/FilteredOptions';
+import { useGlobalDispatch, useGlobalState } from '../Store';
+
+type Props = {
+  option: FilteredOptions;
+};
+
+export const FilterOptions: React.FC<Props> = ({
+  option: { type, href, data },
+}) => {
+  const { filter } = useGlobalState();
+  const dispatch = useGlobalDispatch();
+
+  return (
+    <a
+      href={href}
+      className={cn('filter__link', {
+        selected: type === filter,
+      })}
+      data-cy={data}
+      key={type}
+      onClick={() => dispatch({ type: 'setFilter', payload: type })}
+    >
+      {type}
+    </a>
+  );
+};
diff --git a/src/components/Footer.tsx b/src/components/Footer.tsx
new file mode 100644
index 000000000..b49bfa5d0
--- /dev/null
+++ b/src/components/Footer.tsx
@@ -0,0 +1,65 @@
+import { SelectedFilter } from '../types/SelectedFilter';
+import { FilterOptions } from './FilterOption';
+import { useGlobalDispatch, useGlobalState } from '../Store';
+
+export const Footer = () => {
+  const { todos } = useGlobalState();
+  const dispatch = useGlobalDispatch();
+
+  const filteredOptions = [
+    { type: SelectedFilter.ALL, href: '#/', data: 'FilterLinkAll' },
+
+    { type: SelectedFilter.ACTIVE, href: '#/active', data: 'FilterLinkActive' },
+
+    {
+      type: SelectedFilter.COMPLETED,
+      href: '#/completed',
+      data: 'FilterLinkCompleted',
+    },
+  ];
+
+  const handleMassDeleteTodo = (ids: number[]) => {
+    dispatch({ type: 'massDelete', payload: ids });
+  };
+
+  const itemsLeft = () => {
+    const uncompletedTodos = todos.filter(todo => !todo.completed).length;
+
+    if (uncompletedTodos === 1) {
+      return `${uncompletedTodos} item left`;
+    }
+
+    return `${uncompletedTodos} items left`;
+  };
+
+  const completedTodosIds = todos
+    .filter(todo => todo.completed)
+    .map(todo => todo.id);
+
+  return (
+    <footer className="todoapp__footer" data-cy="Footer">
+      <span className="todo-count" data-cy="TodosCounter">
+        {itemsLeft()}
+      </span>
+
+      <nav className="filter" data-cy="Filter">
+        {filteredOptions.map(option => (
+          <FilterOptions key={option.type} option={option} />
+        ))}
+      </nav>
+
+      <button
+        type="button"
+        className="todoapp__clear-completed"
+        data-cy="ClearCompletedButton"
+        onClick={() => handleMassDeleteTodo(completedTodosIds)}
+        disabled={!completedTodosIds.length}
+        style={{
+          visibility: !completedTodosIds.length ? 'hidden' : 'visible',
+        }}
+      >
+        Clear completed
+      </button>
+    </footer>
+  );
+};
diff --git a/src/components/Header.tsx b/src/components/Header.tsx
new file mode 100644
index 000000000..ecee1aeac
--- /dev/null
+++ b/src/components/Header.tsx
@@ -0,0 +1,33 @@
+import cn from 'classnames';
+import { MainInput } from './MainInput';
+import { useGlobalDispatch, useGlobalState } from '../Store';
+
+export const Header = () => {
+  const { todos } = useGlobalState();
+  const dispatch = useGlobalDispatch();
+
+  const completedTodosIds = todos
+    .filter(todo => todo.completed)
+    .map(todo => todo.id);
+
+  const toogleAllChecked = () => {
+    dispatch({ type: 'toogleAllChecked' });
+  };
+
+  return (
+    <header className="todoapp__header">
+      {!!todos.length && (
+        <button
+          type="button"
+          className={cn('todoapp__toggle-all', {
+            active: completedTodosIds.length === todos.length,
+          })}
+          data-cy="ToggleAllButton"
+          onClick={toogleAllChecked}
+        />
+      )}
+
+      <MainInput />
+    </header>
+  );
+};
diff --git a/src/components/MainInput.tsx b/src/components/MainInput.tsx
new file mode 100644
index 000000000..05b017651
--- /dev/null
+++ b/src/components/MainInput.tsx
@@ -0,0 +1,53 @@
+import { useEffect, useRef } from 'react';
+import { useGlobalDispatch, useGlobalState } from '../Store';
+import { Todo } from '../types/Todo';
+
+export const MainInput = () => {
+  const { query, editingTodoId, todos } = useGlobalState();
+  const dispatch = useGlobalDispatch();
+
+  const mainInputRef = useRef<HTMLInputElement>(null);
+
+  useEffect(() => {
+    if (mainInputRef.current && !editingTodoId) {
+      mainInputRef.current.focus();
+    }
+  }, [todos, editingTodoId]);
+
+  const handleSubmit = (event: React.FormEvent) => {
+    event.preventDefault();
+
+    const trimmedTitle = query.trim();
+
+    if (!trimmedTitle) {
+      return;
+    }
+
+    const newTodo: Todo = {
+      id: +new Date(),
+      title: trimmedTitle,
+      completed: false,
+    };
+
+    dispatch({ type: 'addTodo', payload: newTodo });
+    dispatch({ type: 'setQuery', payload: '' });
+  };
+
+  const handleQueryChange = (event: React.ChangeEvent<HTMLInputElement>) => {
+    dispatch({ type: 'setQuery', payload: event.target.value });
+  };
+
+  return (
+    <form onSubmit={handleSubmit}>
+      <input
+        ref={mainInputRef}
+        data-cy="NewTodoField"
+        type="text"
+        className="todoapp__new-todo"
+        placeholder="What needs to be done?"
+        value={query}
+        onChange={handleQueryChange}
+      />
+    </form>
+  );
+};
diff --git a/src/components/TodoItem.tsx b/src/components/TodoItem.tsx
new file mode 100644
index 000000000..6b6f707de
--- /dev/null
+++ b/src/components/TodoItem.tsx
@@ -0,0 +1,70 @@
+import cn from 'classnames';
+import { Todo } from '../types/Todo';
+import { EditForm } from './EditForm';
+import { useGlobalDispatch, useGlobalState } from '../Store';
+
+type Props = {
+  todo: Todo;
+};
+
+export const TodoItem: React.FC<Props> = ({
+  todo: { id, title, completed },
+}) => {
+  const { editingTodoId } = useGlobalState();
+  const dispatch = useGlobalDispatch();
+
+  const handleDeleteTodo = (index: number) => {
+    dispatch({ type: 'deleteTodo', payload: index });
+  };
+
+  const handleChangeCheckbox = (index: number) => {
+    dispatch({ type: 'changeCheckbox', payload: index });
+  };
+
+  const handleDoubleClick = (editId: number, editTitle: string) => {
+    dispatch({ type: 'setCurrentTitle', payload: editTitle });
+    dispatch({ type: 'setEditingTodoId', payload: editId });
+  };
+
+  return (
+    <div
+      data-cy="Todo"
+      className={cn('todo', {
+        completed: completed,
+      })}
+    >
+      <label className="todo__status-label">
+        <input
+          data-cy="TodoStatus"
+          type="checkbox"
+          className="todo__status"
+          checked={completed}
+          onClick={() => handleChangeCheckbox(id)}
+        />
+      </label>
+
+      {editingTodoId === id ? (
+        <EditForm newTodo={{ id, title, completed }} />
+      ) : (
+        <>
+          <span
+            data-cy="TodoTitle"
+            className="todo__title"
+            onDoubleClick={() => handleDoubleClick(id, title)}
+          >
+            {title}
+          </span>
+
+          <button
+            type="button"
+            className="todo__remove"
+            data-cy="TodoDelete"
+            onClick={() => handleDeleteTodo(id)}
+          >
+            ×
+          </button>
+        </>
+      )}
+    </div>
+  );
+};
diff --git a/src/components/TodoList.tsx b/src/components/TodoList.tsx
new file mode 100644
index 000000000..94a622727
--- /dev/null
+++ b/src/components/TodoList.tsx
@@ -0,0 +1,29 @@
+import { useMemo } from 'react';
+import { TodoItem } from './TodoItem';
+import { useGlobalState } from '../Store';
+import { SelectedFilter } from '../types/SelectedFilter';
+
+export const TodoList = () => {
+  const { todos, filter } = useGlobalState();
+
+  const visibleTodos = useMemo(() => {
+    switch (filter) {
+      case SelectedFilter.ACTIVE:
+        return todos.filter(todo => !todo.completed);
+
+      case SelectedFilter.COMPLETED:
+        return todos.filter(todo => todo.completed);
+
+      default:
+        return todos;
+    }
+  }, [todos, filter]);
+
+  return (
+    <section className="todoapp__main" data-cy="TodoList">
+      {visibleTodos.map(todo => (
+        <TodoItem key={todo.id} todo={todo} />
+      ))}
+    </section>
+  );
+};
diff --git a/src/index.tsx b/src/index.tsx
index a9689cb38..285a018a2 100644
--- a/src/index.tsx
+++ b/src/index.tsx
@@ -1,11 +1,17 @@
 import { createRoot } from 'react-dom/client';
 
-import './styles/index.css';
-import './styles/todo-list.css';
-import './styles/filters.css';
-
 import { App } from './App';
 
+import './styles/index.scss';
+import './styles/todo.scss';
+import './styles/todoapp.scss';
+import './styles/filter.scss';
+import { GlobalStateProvider } from './Store';
+
 const container = document.getElementById('root') as HTMLDivElement;
 
-createRoot(container).render(<App />);
+createRoot(container).render(
+  <GlobalStateProvider>
+    <App />
+  </GlobalStateProvider>,
+);
diff --git a/src/styles/todo.scss b/src/styles/todo.scss
index 4576af434..0eddc2686 100644
--- a/src/styles/todo.scss
+++ b/src/styles/todo.scss
@@ -1,3 +1,7 @@
+* {
+  box-sizing: border-box;
+}
+
 .todo {
   position: relative;
 
diff --git a/src/types/Action.ts b/src/types/Action.ts
new file mode 100644
index 000000000..2df7920ba
--- /dev/null
+++ b/src/types/Action.ts
@@ -0,0 +1,14 @@
+import { SelectedFilter } from './SelectedFilter';
+import { Todo } from './Todo';
+
+export type Action =
+  | { type: 'toogleAllChecked' }
+  | { type: 'addTodo'; payload: Todo }
+  | { type: 'setQuery'; payload: string }
+  | { type: 'deleteTodo'; payload: number }
+  | { type: 'massDelete'; payload: number[] }
+  | { type: 'changeCheckbox'; payload: number }
+  | { type: 'updateTodo'; payload: Todo }
+  | { type: 'setCurrentTitle'; payload: string }
+  | { type: 'setEditingTodoId'; payload: number | null }
+  | { type: 'setFilter'; payload: SelectedFilter };
diff --git a/src/types/FilteredOptions.ts b/src/types/FilteredOptions.ts
new file mode 100644
index 000000000..880e3264c
--- /dev/null
+++ b/src/types/FilteredOptions.ts
@@ -0,0 +1,7 @@
+import { SelectedFilter } from './SelectedFilter';
+
+export type FilteredOptions = {
+  type: SelectedFilter;
+  href: string;
+  data: string;
+};
diff --git a/src/types/SelectedFilter.ts b/src/types/SelectedFilter.ts
new file mode 100644
index 000000000..e41ff3695
--- /dev/null
+++ b/src/types/SelectedFilter.ts
@@ -0,0 +1,5 @@
+export enum SelectedFilter {
+  ALL = 'All',
+  ACTIVE = 'Active',
+  COMPLETED = 'Completed',
+}
diff --git a/src/types/State.ts b/src/types/State.ts
new file mode 100644
index 000000000..b54ce40ba
--- /dev/null
+++ b/src/types/State.ts
@@ -0,0 +1,10 @@
+import { SelectedFilter } from './SelectedFilter';
+import { Todo } from './Todo';
+
+export type State = {
+  todos: Todo[];
+  query: string;
+  filter: SelectedFilter;
+  editingTodoId: number | null;
+  currentTitle: string;
+};
diff --git a/src/types/Todo.ts b/src/types/Todo.ts
new file mode 100644
index 000000000..d94ea1bff
--- /dev/null
+++ b/src/types/Todo.ts
@@ -0,0 +1,5 @@
+export type Todo = {
+  id: number;
+  title: string;
+  completed: boolean;
+};
diff --git a/src/utils/LocaleStorage.ts b/src/utils/LocaleStorage.ts
new file mode 100644
index 000000000..2f8bfa692
--- /dev/null
+++ b/src/utils/LocaleStorage.ts
@@ -0,0 +1,7 @@
+import { Todo } from '../types/Todo';
+
+export const loadFromLocalStorage = (key: string): Todo[] => {
+  const todos = localStorage.getItem(key);
+
+  return todos ? JSON.parse(todos) : [];
+};