菜单css样式不起作用

Question

我正在为我的网站制作一个菜单。我想让它响应，所以使用bootstrap折叠它并只显示徽标/项目标题。

我尝试添加类“崩溃”或“navbar-collapse”但没有效果。我甚至无法在菜单中添加下拉菜单，我不知道为什么会发生这种情况？有人可以帮助我： 这是我的小提琴：jsfiddle

我的HTML代码：

<div id='cssmenu'>   
    <ul>
        <li id="logo"><a class="project-name-align"href="#">#MyProject</a></li>
        <li class='active'><a href='#'><span>Home</span></a></li>
        <li><a href='#'><span>Products</span></a></li>
        <li><a href='#'><span>Company</span></a></li>
        <li class='last'><a href='#'><span>Contact</span></a></li>
    </ul>
</div>

我的css代码：

@import url(http://fonts.googleapis.com/css?family=Open+Sans:700);
#cssmenu {
  background: #000000;
  width: auto;
  padding-top:20px;
  height:80px;
  text-align:right;
  padding-right:10px;
}

.project-name-align{
  text-align:left !important;
} 
#logo a:hover{
  color: #d94939 !important;
}

#cssmenu ul {
  list-style: none;
  margin: 0;
  padding: 0;
  line-height: 1;
  display: block;
  zoom: 1;
}

#cssmenu ul:after {
  content: " ";
  display: block;
  font-size: 0;
  height: 0;
  clear: both;
  visibility: hidden;
}

#cssmenu ul li {
  display: inline-block;
  padding: 0;
  margin: 0;
}

#cssmenu.align-right ul li {
  float: right;
}

#cssmenu.align-center ul {
  text-align: center;
}

#cssmenu ul li a {
  color: #ffffff;
  text-decoration: none;
  display: block;
  padding: 15px 25px;
  font-family: 'Open Sans', sans-serif;
  font-weight: 700;
  text-transform: uppercase;
  font-size: 14px;
  position: relative;
  -webkit-transition: color .25s;
  -moz-transition: color .25s;
  -ms-transition: color .25s;
  -o-transition: color .25s;
  transition: color .25s;
}

#cssmenu ul li a:hover {
  color: #d94939;
}

#cssmenu ul li a:hover:before {
  width: 100%;
}

#cssmenu ul li a:after {
  content: "";
  display: block;
  position: absolute;
  right: -3px;
  top: 19px;
  height: 6px;
  width: 6px;
  background: #ffffff;
  opacity: .5;
}

#cssmenu ul li a:before {
  content: "";
  display: block;
  position: absolute;
  left: 0;
  bottom: 0;
  height: 3px;
  width: 0;
  background: #d94939;
  -webkit-transition: width .25s;
  -moz-transition: width .25s;
  -ms-transition: width .25s;
  -o-transition: width .25s;
  transition: width .25s;
}

#cssmenu ul li.last > a:after,
#cssmenu ul li:last-child > a:after {
  display: none;
}

#cssmenu ul li.active a {
  color: #d94939;
}

#cssmenu ul li.active a:before {
  width: 100%;
}

#cssmenu.align-right li.last > a:after,
#cssmenu.align-right li:last-child > a:after {
  display: block;
}

#cssmenu.align-right li:first-child a:after {
  display: none;
}