diff --git a/app.js b/app.js
index ab737a600..1f38204f3 100644
--- a/app.js
+++ b/app.js
@@ -5,191 +5,171 @@
 //Solution: Add interactivity so the user can manage daily tasks.
 //Break things down into smaller steps and take each step at a time.
 
-
 // Event handling, user interaction is what starts the code execution.
 
-var taskInput=document.getElementById("new-task");//Add a new task.
-var addButton=document.getElementsByTagName("button")[0];//first button
-var incompleteTaskHolder=document.getElementById("incompleteTasks");//ul of #incompleteTasks
-var completedTasksHolder=document.getElementById("completed-tasks");//completed-tasks
-
+var taskInput = document.getElementById("new-task"); //Add a new task.
+var addButton = document.getElementsByTagName("button")[0]; //first button
+//var incompleteTaskHolder=document.getElementById("incompleteTasks");//ul of #incompleteTasks
+var incompleteTaskHolder = document.getElementById("todo-tasks"); //ul of #todo-tasks
+var completedTasksHolder = document.getElementById("completed-tasks"); //completed-tasks
 
 //New task list item
-var createNewTaskElement=function(taskString){
-
-    var listItem=document.createElement("li");
-
-    //input (checkbox)
-    var checkBox=document.createElement("input");//checkbx
-    //label
-    var label=document.createElement("label");//label
-    //input (text)
-    var editInput=document.createElement("input");//text
-    //button.edit
-    var editButton=document.createElement("button");//edit button
-
-    //button.delete
-    var deleteButton=document.createElement("button");//delete button
-    var deleteButtonImg=document.createElement("img");//delete button image
-
-    label.innerText=taskString;
-    label.className='task';
-
-    //Each elements, needs appending
-    checkBox.type="checkbox";
-    editInput.type="text";
-    editInput.className="task";
-
-    editButton.innerText="Edit"; //innerText encodes special characters, HTML does not.
-    editButton.className="edit";
-
-    deleteButton.className="delete";
-    deleteButtonImg.src='./remove.svg';
-    deleteButton.appendChild(deleteButtonImg);
-
-
-    //and appending.
-    listItem.appendChild(checkBox);
-    listItem.appendChild(label);
-    listItem.appendChild(editInput);
-    listItem.appendChild(editButton);
-    listItem.appendChild(deleteButton);
-    return listItem;
-}
-
-
-
-var addTask=function(){
-    console.log("Add Task...");
-    //Create a new list item with the text from the #new-task:
-    if (!taskInput.value) return;
-    var listItem=createNewTaskElement(taskInput.value);
+var createNewTaskElement = function (taskString) {
+  var listItem = document.createElement("li");
+
+  listItem.className = "li"; // не закончил
+
+  //input (checkbox)
+  var checkBox = document.createElement("input"); //checkbx
+  //label
+  var label = document.createElement("label"); //label
+  //input (text)
+  var editInput = document.createElement("input"); //text
+  //button.edit
+  var editButton = document.createElement("button"); //edit button
+
+  //button.delete
+  var deleteButton = document.createElement("button"); //delete button
+  var deleteButtonImg = document.createElement("img"); //delete button image
+
+  label.innerText = taskString;
+  label.className = "task";
+
+  //Each elements, needs appending
+  checkBox.type = "checkbox";
+  editInput.type = "text";
+  editInput.className = "task task_text";
+
+  editButton.innerText = "Edit"; //innerText encodes special characters, HTML does not.
+  editButton.className = "button button_edit";
+
+  deleteButton.className = "button button_delete";
+  deleteButtonImg.src = "./remove.svg";
+  deleteButtonImg.className = "button__img_delete";
+  deleteButton.appendChild(deleteButtonImg);
+
+  //and appending.
+  listItem.appendChild(checkBox);
+  listItem.appendChild(label);
+  listItem.appendChild(editInput);
+  listItem.appendChild(editButton);
+  listItem.appendChild(deleteButton);
+  return listItem;
+};
 
-    //Append listItem to incompleteTaskHolder
-    incompleteTaskHolder.appendChild(listItem);
-    bindTaskEvents(listItem, taskCompleted);
+var addTask = function () {
+  console.log("Add Task...");
+  //Create a new list item with the text from the #new-task:
+  if (!taskInput.value) return;
+  var listItem = createNewTaskElement(taskInput.value);
+  listItem.className = "li add-label__input"; // не закончил
 
-    taskInput.value="";
+  //Append listItem to incompleteTaskHolder
+  incompleteTaskHolder.appendChild(listItem);
+  bindTaskEvents(listItem, taskCompleted);
 
-}
+  taskInput.value = "";
+};
 
 //Edit an existing task.
 
-var editTask=function(){
-    console.log("Edit Task...");
-    console.log("Change 'edit' to 'save'");
-
-
-    var listItem=this.parentNode;
-
-    var editInput=listItem.querySelector('input[type=text]');
-    var label=listItem.querySelector("label");
-    var editBtn=listItem.querySelector(".edit");
-    var containsClass=listItem.classList.contains("editMode");
-    //If class of the parent is .editmode
-    if(containsClass){
-
-        //switch to .editmode
-        //label becomes the inputs value.
-        label.innerText=editInput.value;
-        editBtn.innerText="Edit";
-    }else{
-        editInput.value=label.innerText;
-        editBtn.innerText="Save";
-    }
-
-    //toggle .editmode on the parent.
-    listItem.classList.toggle("editMode");
+var editTask = function () {
+  console.log("Edit Task...");
+  console.log("Change 'edit' to 'save'");
+
+  var listItem = this.parentNode;
+
+  var editInput = listItem.querySelector("input[type=text]");
+  var label = listItem.querySelector("label");
+  var editBtn = listItem.querySelector(".button_edit");
+  //var containsClass=listItem.classList.contains("editMode");
+  var containsClass = listItem.classList.contains("li_edit-mode");
+  //If class of the parent is .editmode
+  if (containsClass) {
+    //switch to .editmode
+    //label becomes the inputs value.
+    label.innerText = editInput.value;
+    editBtn.innerText = "Edit";
+  } else {
+    editInput.value = label.innerText;
+    editBtn.innerText = "Save";
+  }
+
+  //toggle .editmode on the parent.
+  listItem.classList.toggle("li_edit-mode");
+  //listItem.classList.toggle("editMode");
 };
 
-
 //Delete task.
-var deleteTask=function(){
-    console.log("Delete Task...");
-
-    var listItem=this.parentNode;
-    var ul=listItem.parentNode;
-    //Remove the parent list item from the ul.
-    ul.removeChild(listItem);
-
-}
+var deleteTask = function () {
+  console.log("Delete Task...");
 
+  var listItem = this.parentNode;
+  var ul = listItem.parentNode;
+  //Remove the parent list item from the ul.
+  ul.removeChild(listItem);
+};
 
 //Mark task completed
-var taskCompleted=function(){
-    console.log("Complete Task...");
-
-    //Append the task list item to the #completed-tasks
-    var listItem=this.parentNode;
-    completedTasksHolder.appendChild(listItem);
-    bindTaskEvents(listItem, taskIncomplete);
-
-}
-
-
-var taskIncomplete=function(){
-    console.log("Incomplete Task...");
-//Mark task as incomplete.
-    //When the checkbox is unchecked
-    //Append the task list item to the #incompleteTasks.
-    var listItem=this.parentNode;
-    incompleteTaskHolder.appendChild(listItem);
-    bindTaskEvents(listItem,taskCompleted);
-}
+var taskCompleted = function () {
+  console.log("Complete Task...");
 
+  //Append the task list item to the #completed-tasks
+  var listItem = this.parentNode;
+  completedTasksHolder.appendChild(listItem);
+  bindTaskEvents(listItem, taskIncomplete);
+};
 
+var taskIncomplete = function () {
+  console.log("Incomplete Task...");
+  //Mark task as incomplete.
+  //When the checkbox is unchecked
+  //Append the task list item to the #todo-tasks.
+  var listItem = this.parentNode;
+  incompleteTaskHolder.appendChild(listItem);
+  bindTaskEvents(listItem, taskCompleted);
+};
 
-var ajaxRequest=function(){
-    console.log("AJAX Request");
-}
+var ajaxRequest = function () {
+  console.log("AJAX Request");
+};
 
 //The glue to hold it all together.
 
-
 //Set the click handler to the addTask function.
-addButton.onclick=addTask;
-addButton.addEventListener("click",addTask);
-addButton.addEventListener("click",ajaxRequest);
-
-
-var bindTaskEvents=function(taskListItem,checkBoxEventHandler){
-    console.log("bind list item events");
-//select ListItems children
-    var checkBox=taskListItem.querySelector("input[type=checkbox]");
-    var editButton=taskListItem.querySelector("button.edit");
-    var deleteButton=taskListItem.querySelector("button.delete");
-
-
-    //Bind editTask to edit button.
-    editButton.onclick=editTask;
-    //Bind deleteTask to delete button.
-    deleteButton.onclick=deleteTask;
-    //Bind taskCompleted to checkBoxEventHandler.
-    checkBox.onchange=checkBoxEventHandler;
-}
+addButton.onclick = addTask;
+addButton.addEventListener("click", addTask);
+addButton.addEventListener("click", ajaxRequest);
+
+var bindTaskEvents = function (taskListItem, checkBoxEventHandler) {
+  console.log("bind list item events");
+  //select ListItems children
+  var checkBox = taskListItem.querySelector("input[type=checkbox]");
+  var editButton = taskListItem.querySelector("button.button_edit");
+  var deleteButton = taskListItem.querySelector("button.button_delete");
+
+  //Bind editTask to edit button.
+  editButton.onclick = editTask;
+  //Bind deleteTask to delete button.
+  deleteButton.onclick = deleteTask;
+  //Bind taskCompleted to checkBoxEventHandler.
+  checkBox.onchange = checkBoxEventHandler;
+};
 
 //cycle over incompleteTaskHolder ul list items
 //for each list item
-for (var i=0; i<incompleteTaskHolder.children.length;i++){
-
-    //bind events to list items chldren(tasksCompleted)
-    bindTaskEvents(incompleteTaskHolder.children[i],taskCompleted);
+for (var i = 0; i < incompleteTaskHolder.children.length; i++) {
+  //bind events to list items chldren(tasksCompleted)
+  bindTaskEvents(incompleteTaskHolder.children[i], taskCompleted);
 }
 
-
-
-
 //cycle over completedTasksHolder ul list items
-for (var i=0; i<completedTasksHolder.children.length;i++){
-    //bind events to list items chldren(tasksIncompleted)
-    bindTaskEvents(completedTasksHolder.children[i],taskIncomplete);
+for (var i = 0; i < completedTasksHolder.children.length; i++) {
+  //bind events to list items chldren(tasksIncompleted)
+  bindTaskEvents(completedTasksHolder.children[i], taskIncomplete);
 }
 
-
-
-
 // Issues with usability don't get seen until they are in front of a human tester.
 
 //prevent creation of empty tasks.
 
-//Change edit to save when you are in edit mode.
\ No newline at end of file
diff --git a/index.html b/index.html
index ef4aa1f60..0f7004bcc 100644
--- a/index.html
+++ b/index.html
@@ -1,19 +1,70 @@
-<html>
-<HEAD><title>Todo App</title>
-<link href='https://fonts.googleapis.com/css?family=Lato:300,400,700' rel='stylesheet' type='text/css'>
-<link rel="stylesheet" href="style.css" type="text/css" MEDIA="screen" charset="utf-8">
-</HEAD>
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <meta charset="UTF-8">
+  <meta http-equiv="X-UA-Compatible" content="IE=edge">
+  <meta name="viewport" content="width=device-width, initial-scale=1.0">
+  <title>Todo App</title>
+  <link href="https://fonts.googleapis.com/css?family=Lato:300,400,700" rel="stylesheet" type="font/woff2">
+  <link href="./style.css" rel="stylesheet" media="screen">
+</head>
 <body>
-<div class="aaa"><img src="./eisenhower-matrix.jpg"><a class='more_inf' href="https://goal-life.com/page/method/matrix-eisenhower">Want more details&quest;</a></div>
-<div class="centered-main-page-element"><p id='topSectionForAddingElementToList'><label for="new-task">Add Item</label><div class="task-row-wrapper"><input id='new-task'class="task" type="text"><button>Add</button></div>
-</p><h3>Todo</h3>
-<ul id='incompleteTasks'>
-<li><input type='checkbox'><label class="task">Pay Bills</label><input type="text" class="task"><button class="edit">Edit</button><button class="delete"><img src="./remove.svg"></button></li>
-<li class="editMode"><input type="checkbox"><label class="task">Go Shopping</label><input type="text" value="Go Shopping" class="task"><button class='edit'>Save</button><button class="delete"><img src="./remove.svg"></button></li>
-</ul><h3>Completed</h3><ul id="completed-tasks"><li><input type="checkbox" checked><label class="task">See the Doctor</label><input type="text" class="task"><button class="edit">Edit</button><button class="delete"><img src="./remove.svg"></button>
-</li>
-</ul>
-</div>
-<script type="text/javascript" SRC="app.js"></script>
+
+  <header class="header">
+    <div class="container container_header">
+      <img class="header__start-img" src="./eisenhower-matrix.jpg" alt="Eisenhower-matrix">
+      <a class="header__link" href="https://goal-life.com/page/method/matrix-eisenhower">Want more details?</a>
+    </div>
+  </header>
+
+  <main class="main">
+    <div class="container">
+
+      <section class="add">
+        <h3 class="title add__title">Add Item</h3>
+        <label class="add-label" for="new-task"></label>
+        <div class="add-label__wrapper">
+          <input class="task task_text add-label__input" id="new-task" type="text">
+          <button class="button button_add add-label__btn">Add</button>
+        </div>
+      </section>
+
+      <section class="todo">
+        <h3 class="title todo__title">Todo</h3>
+        <ul class="todo-tasks" id="todo-tasks">
+          <li class="li">
+            <input class="li__input-checkbox" type="checkbox">
+            <label class="task li__label">Pay Bills</label>
+            <input class="task task_text li__input-text" type="text">
+            <button class="button button_edit">Edit</button>
+            <button class="button button_delete"><img class="button__img_delete" src="./remove.svg" alt="delete"></button>
+          </li>
+          <li class="li li_edit-mode">
+            <input class="li__input-checkbox" type="checkbox">
+            <label class="task li__label">Go Shopping</label>
+            <input class="task task_text li__input-text" type="text" value="Go Shopping">
+            <button class="button button_edit">Save</button>
+            <button class="button button_delete"><img class="button__img_delete" src="./remove.svg" alt="delete"></button>
+          </li>
+        </ul>
+      </section>
+
+      <section class="completed">
+        <h3 class="title completed__title">Completed</h3>
+        <ul class="completed-tasks" id="completed-tasks">
+          <li class="li">
+            <input class="li__input-checkbox" type="checkbox" checked>
+            <label class="task li__label" >See the Doctor</label>
+            <input class="task task_text li__input-text" type="text">
+            <button class="button button_edit">Edit</button>
+            <button class="button button_delete"><img class="button__img_delete" src="./remove.svg" alt="delete"></button>
+          </li>
+        </ul>
+      </section>
+
+    </div>
+  </main>
+
+  <script src="./app.js"></script>
 </body>
 </html>
\ No newline at end of file
diff --git a/style.css b/style.css
index ab3622770..004add1cb 100644
--- a/style.css
+++ b/style.css
@@ -1,148 +1,176 @@
-/* Basic Style */
-body {
-    background-color: #f8f8f8;
-    color: #333;
-    font-family: Lato, sans-serif;
-}
-.aaa {
-    width: 500px;
-    margin: 0 auto;
-    display: block;
-    text-align: right;
+/* reset CSS style *************/
+
+ul {
+  margin: 0;
+  padding: 0;
 }
-.aaa img {
-    width: 100%;
+
+li,
+h3 {
+  list-style: none;
 }
-.aaa .more_inf {
-    font-family: fantasy, cursive;
+
+input,
+button {
+  outline: none;
 }
 
-@media (max-width:768px) {
-.aaa { text-align: center;
+/* Basic Style **************/
+
+.header,
+.main {
+  background-color: #f8f8f8;
+  color: #333;
+  font-family: Lato, sans-serif;
 }
+
+.container {
+  width: 500px;
+  margin: 0 auto;
+  display: block;
 }
-.centered-main-page-element {
-    display: block;
-    width: 500px;
-    margin: 0 auto 0;
+
+.container_header {
+  text-align: right;
 }
-.task {
-    width: 56%;
-    display: inline-block;
-    flex-grow: 1
+
+.header__start-img {
+  width: 100%;
 }
-.task-row-wrapper {
-    display: flex;
+
+.header__link {
+  font-family: fantasy, cursive;
 }
-ul {
-    margin:0;
-    padding: 0px;
+
+@media (max-width: 768px) {
+  .container_header {
+    text-align: center;
+  }
 }
-li, h3 {
-    list-style:none;
+
+.task {
+  width: 56%;
+  display: inline-block;
+  flex-grow: 1;
 }
-input,button{
-    outline:none;
+
+.add-label__wrapper {
+  display: flex;
+  justify-content: space-between;
 }
-button {
-    background: none;
-    border: 0px;
-    color: #888;
-    font-size: 15px;
-    width: 60px;
-    font-family: Lato, sans-serif;
-    cursor: pointer;
+
+.button {
+  background: none;
+  border: 0;
+  color: #888;
+  font-size: 15px;
+  width: 60px;
+  font-family: Lato, sans-serif;
+  cursor: pointer;
 }
-button:hover {
-    color: #3a3A3a;
+
+.button:hover {
+  color: #3a3a3a;
 }
-/* Heading */
-h3,
-label[for='new-task'] {
-    color: #333;
-    font-weight: 700;
-    font-size: 15px;
-    border-bottom: 2px solid #333;
-    padding: 30px 0 10px;
-    margin: 0;
-    text-transform: uppercase;
+
+/* Heading ****************/
+
+.title {
+  color: #333;
+  font-weight: 700;
+  font-size: 15px;
+  border-bottom: 2px solid #333;
+  padding: 30px 0 10px;
+  margin: 0;
+  text-transform: uppercase;
 }
-input[type="text"] {
-    margin: 0;
-    font-size: 18px;
-    line-height: 18px;
-    height: 21px;
-    padding: 0 9px;
-    border: 1px solid #dDd;
-    background: #FFF;
-    border-radius: 6px;
-    font-family: Lato, sans-serif;
-    color: #888;
+
+.task_text {
+  margin: 0;
+  font-size: 18px;
+  line-height: 18px;
+  height: 21px;
+  padding: 0 9px;
+  border: 1px solid #ddd;
+  background: #fff;
+  border-radius: 6px;
+  font-family: Lato, sans-serif;
+  color: #888;
 }
-input[type="text"]:focus {
-    color: #333;
+
+.task_text:focus {
+  color: #333;
 }
 
-/* New Task */
-label[for='new-task'] {
-    display: block;
-    margin: 0 0 20px;
+/* New Task ************************/
+
+.add-label {
+  display: block;
+  margin-bottom: 20px;
 }
-input#new-task {
-    width: 318px;
+
+.add-label__input {
+  width: 318px;
 }
 
-/* Task list */
-li {
-    overflow: hidden;
-    padding: 20px 0;
-    border-bottom: 1px solid #eee;
+/* Task list *********************/
 
-    display: flex;
-    justify-content: space-between;
-    align-items: center;
+.li {
+  overflow: hidden;
+  padding: 20px 0;
+  border-bottom: 1px solid #eee;
+  display: flex;
+  justify-content: space-between;
+  align-items: center;
 }
-li > * {
-    vertical-align: middle;
+
+.li {
+  vertical-align: middle;
 }
 
-li > input[type="checkbox"] {
-    margin: 0 10px;
+.li__input-checkbox {
+  margin: 0 10px;
 }
-li > label {
-    padding-left: 10px;
-    box-sizing: border-box;
-    font-size: 18px;
-    width: 226px;
+
+.li__label {
+  padding-left: 10px;
+  box-sizing: border-box;
+  font-size: 18px;
+  width: 226px;
 }
-li >    input[type="text"] {
-    width: 226px
+
+.li__input-text {
+  width: 226px;
 }
-button.delete img {
-    height: 2em;
-    transform: rotateZ(45deg);
-    transition: transform 200ms ease-in;
+
+.button__img_delete {
+  height: 2em;
+  transform: rotateZ(45deg);
+  transition: transform 200ms ease-in;
 }
-button.delete img:hover {
-    transform: rotateZ(0);
+
+.button__img_delete:hover {
+  transform: rotateZ(0);
 }
 
-/* Completed */
-ul#completed-tasks label {
-    text-decoration: line-through
-    color: #888;
+/* Completed ***********************/
+
+.completed-tasks .li__label {
+  text-decoration: line-through;
+  color: #888;
 }
 
-/* Edit Task */
-ul li input[type=text] {
-    display:none
+/* Edit Task *************************/
+
+.li__input-text {
+  display: none;
 }
 
-ul li.editMode input[type=text] {
-    display:inline-block;
-    width:224px
+.li_edit-mode .li__input-text {
+  display: inline-block;
+  width: 224px;
 }
 
-ul li.editMode label {
-    display:none;
-}
\ No newline at end of file
+.li_edit-mode .li__label {
+  display: none;
+}