JSFiddle - React, Tailwind, and code Playground

HTML

<body>
    <div class="container">
      <p>
        <label for="new-task">Add Item</label><input id="new-task" type="text"><button>Add</button>
      </p>
      
      <h3>Todo</h3>
      <ul id="incomplete-tasks">
        <li><input type="checkbox"><label>Pay Bills</label><input type="text"><button class="edit">Edit</button><button class="delete">Delete</button></li>
        <li ><input type="checkbox"><label>Go Shopping</label><input type="text" value="Go Shopping"><button class="edit">Edit</button><button class="delete">Delete</button></li>
        
      </ul>
      
      <h3>Completed</h3>
      <ul id="completed-tasks">
        <li><input type="checkbox" checked><label>See the Doctor</label><input type="text"><button class="edit">Edit</button><button class="delete">Delete</button></li>
      </ul>
    </div>
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.3/jquery.min.js"></script>
    <script type="text/javascript" src="js/app.js"></script>

  </body>
</html>

CSS

/* Basic Style */
body {
  background: #fff;
  color: #333;
  font-family: Lato, sans-serif;
}
.container {
  display: block;
  width: 400px;
  margin: 100px auto 0;
}
ul {
  margin: 0;
  padding: 0;
}
li * {
  float: left;
}
li, h3 {
  clear:both;
  list-style:none;
}
input, button {
  outline: none;
}
button {
  background: none;
  border: 0px;
  color: #888;
  font-size: 15px;
  width: 60px;
  margin: 10px 0 0;
  font-family: Lato, sans-serif;
  cursor: pointer;
}
button:hover {
  color: #333;
}
/* 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;
}
input[type="text"] {
  margin: 0;
  font-size: 18px;
  line-height: 18px;
  height: 18px;
  padding: 10px;
  border: 1px solid #ddd;
  background: #fff;
  border-radius: 6px;
  font-family: Lato, sans-serif;
  color: #888;
}
input[type="text"]:focus {
  color: #333;
}

/* New Task */
label[for='new-task'] {
  display: block;
  margin: 0 0 20px;
}
input#new-task {
  float: left;
  width: 318px;
}
p > button:hover {
  color: #0FC57C;
}

/* Task list */
li {
  overflow: hidden;
  padding: 20px 0;
  border-bottom: 1px solid #eee;
}
li > input[type="checkbox"] {
  margin: 0 10px;
  position: relative;
  top: 15px;
}
li > label {
  font-size: 18px;
  line-height: 40px;
  width: 237px;
  padding: 0 0 0 11px;
}
li >  input[type="text"] {
  width: 226px;
}
li > .delete:hover {
  color: #CF2323;
}

/* Completed */
#completed-tasks label {
  text-decoration: line-through;
  color: #888;
}

/* Edit Task */
ul li input[type=text] {
  display:none;
}

ul li.editMode input[type=text] {
  display:block;
}

ul li.editMode label {
  display:none;
}

JavaScript

//Problem: User interaction doesnt provide desired results
//Solution: Add interactivity so user can manage daily tasks


var taskInput = document.getElementById("new-task"); //new-task
var addButton = document.getElementsByTagName("button")[0]; //First Button
var incompleteTasksHolder = document.getElementById("incomplete-tasks"); //#incomplete-tasks
var completedTasksHolder = document.getElementById("completed-tasks"); //#completed-tasks

//New task list item
var createNewTaskElement = function (taskString) {

  //Create list item
  var listItem = document.createElement("li");

  //input checkbox
  var checkBox = document.createElement("input"); //Type Checkbox

  //label
  var label = document.createElement("label");

  //input (text)
  var editInput = document.createElement("input");

  //button.edit
  var editButton = document.createElement("button");

  //button.delete
  var deleteButton = document.createElement("button");

  //each elements, needs modifying
  checkBox.type = "checkbox";
  editInput.type = "text";

  editButton.innerText = "Edit";
  editButton.className = "edit";

  deleteButton.innerText = "Delete";
  deleteButton.className = "delete";

  label.innerText = taskString;



  //Each element neeeds appeneding
  listItem.appendChild(checkBox);
  listItem.appendChild(label);
  listItem.appendChild(editInput);
  listItem.appendChild(editButton);
  listItem.appendChild(deleteButton);

  return listItem;
}


//Add a new task
var addTask = function () {
  if (taskInput.value !== " ") {
    console.log("Add task....");
    //Create a new list item with the text from #new-task
    var listItem = createNewTaskElement(taskInput.value);

    //Append listItem to incompleteTasksHolder
    incompleteTasksHolder.appendChild(listItem);
    bindTaskEvents(listItem, taskCompleted);
  } else { //Alert message displayed when text input is blank.
    alert("Please enter an item.");
  }
  taskInput.value = " ";
}


//Edit an existing task
var editTask = function...