1:55 Menu CSS not in project downloads

/*
Theme Name: Bootstrap to WordPress
Theme URI: http://wptreehouse.com/from-bootstrap-to-wordpress
Author: Zac Gordon
Author URI: http://wp.zacgordon.com/
Description: Example theme for Treehouse course on how to convert static Bootstrap site into dynamic WordPress theme
Version: 1.0
License: GNU General Public License v2 or later
License URI: http://www.gnu.org/licenses/gpl-2.0.html
Text Domain: bootstrap-to-wp

This theme, like WordPress, is licensed under the GPL.
Use it to make something cool, have fun, and share what you've learned with others.
*/

body {
  padding-top: 50px;
  padding-bottom: 20px;
}

.admin-bar .navbar-fixed-top {
    margin-top: 30px;
}

@media (min-width:768px) {
    .sub-menu {
        display: none;
        position: absolute;
        background: #222;
        padding: 10px 15px;
        width: 200px;       
    }

    li:hover .sub-menu {
        display: block;
    }

}

.sub-menu li {
    margin-bottom: 10px;
    list-style: none;
}

.sub-menu li:last-child {
    margin-bottom: 0;
}

.sub-menu a  {
    color: #999;
    text-decoration: none;
}

.sub-menu a:hover  {
    color: #fff;    
}   

.current-menu-item > a, .current-menu-parent > a {
    background: #000;   
}
.current-menu-parent li a {
    background: inherit;
}
.current-menu-parent .current-menu-item a {
    color: #fff;
    font-weight: bold;
}