Is it possible to hide the string Last Name inside a th by using CSS?
It is important that table's background color, font size etc will not be affected.
<html lang="en">
<head>
  <title></title>
  <link href="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.4/css/bootstrap-theme.css" rel="stylesheet" />
  <link href="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.4/css/bootstrap.min.css" rel="stylesheet" />
  <script src="https://code.jquery.com/jquery-1.11.3.min.js"></script>
  <script src="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.4/js/bootstrap.min.js"></script>
</head>
<body>
  <br>
  <table>
    <tr>
      <th>#</th>
      <th>First Name</th>
      <th>Last Name</th>
      <th>Username</th>
    </tr>
    <tr>
      <td>1</td>
      <td>Mark</td>
      <td>Otto</td>
      <td>@mdo</td>
    </tr>
  </table>
</body>
</html>