<html>

<head>
  <title>Course example</title>
  <link rel="stylesheet" href="css/styles.css" />
</head>

<body>
  <div id="list_section">
    <h1 id="header">To-do list</h1>
    <ul>
      <li class="item">Buy movie tickets</li>
    </ul>
    <div id="newItemButton"><button href="#">new item</button></div>
    <form id="newItemForm">
      <input type="text" id="itemField" placeholder="Item" />
      <input type="submit" id="add" value="add" />
    </form>
  </div>
  <script src="https://code.jquery.com/jquery-1.12.3.js" integrity="sha256-1XMpEtA4eKXNNpXcJ1pmMPs8JV+nwLdEqwiJeCQEkyc=" crossorigin="anonymous"></script>
  <script src="js/your_js_file.js"></script>
</body>

</html>
body {
  background-color: #85cff7;
  font-family: 'Helvetica', 'Arial', sans-serif;
}

#list_section {
  text-align: center;
}

h1 {
  color: white;
  margin: 0px auto;
  padding: 20px;
}

ul {
  padding: 0;
}

li {
  background-color: #fff;
  color: #000;
  font-size: 20px;
  list-style-type: none;
  width: 20%;
  margin: 0px auto;
  border-radius: 3px;
  border: 1px solid #000;
  padding: 10px;
  margin-bottom: 10px;
}

p {
  background-color: #fff;
  color: #666;
  padding: 10px;
  display: inline-block;
  margin: 20px auto 20px auto;
  width: 80%;
  border-radius: 5px;
  text-align: center;
}

.item {
  background-color: #fff;
  color: #000;
}

input[type='text'] {
  font-size: 12px;
  padding: 6px;
  border: 1px solid #000;
  border-radius: 3px;
}

input[type='submit'] {
  background-color: #fff;
  color: #000;
  border-radius: 8px;
  border: none;
  padding: 5px;
}

#newItemButton {
  display: none;
}

#itemField {
  margin-top: 60px;
  width: 10%;
}
$(function() {

  var $list, $newItemForm;
  $list = $('ul');
  $newItemForm = $('#newItemForm');

  $newItemForm.on('submit', function(e) {
    e.preventDefault();
    var text = $('input:text').val();
    $list.append('<li>' + text + '</li>');
    $('input:text').val('');
  });

  $list.on('click', 'li', function() {
    var $this = $(this);
    $this.remove();
  });

});

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

  1. //cdnjs.cloudflare.com/ajax/libs/jquery/2.2.2/jquery.min.js