HTML/CSS 菜单栏在调整窗口大小时忽略它的形状

Question

我做了一个如下图的菜单栏，Contact item在Company item的左边，当我调整浏览器的大小时Contact就消失了，请问是什么问题？这是图片 http://oi61.tinypic.com/64h01g.jpg

HTML

<div id="header"><h1><center>Online Shopping</center></h1></div>
<div id='cssmenu'>
  <ul>
   <li class='active'><a href='index.html'><span>Home</span></a></li>
   <li class='has-sub'><a href='#'><span>Products</span></a>
  <ul>
     <li><a href='#'><span>Widgets</span></a></li>
     <li><a href='#'><span>Menus</span></a></li>
     <li class='last'><a href='#'><span>Products</span></a></li>
  </ul>
  </li>
<li class='has-sub'><a href='#'><span>Company</span></a>
  <ul>
     <li><a href='#'><span>About</span></a></li>
     <li class='last'><a href='#'><span>Location</span></a></li>
  </ul>
 </li>
 <li class='last'><a href='#'><span>Contact</span></a></li>
 </ul>
 </div>

CSS

body{
background:#EBEBEB;
}
#header{
padding:0;
margin:0;
height:100px;
background:#6355BD;
}
#cssmenu ul {
margin: 0;
padding: 7px 6px 0;
background: #7d7d7d url(images/overlay.png) repeat-x 0 -110px;
line-height: 100%;
border-radius: 1em;
font: normal 0.5333333333333333em Arial, Helvetica, sans-serif;
-webkit-border-radius: 5px;
-moz-border-radius: 5px;
border-radius: 5px;
-webkit-box-shadow: 0 1px 3px rgba(0, 0, 0, 0.4);
-moz-box-shadow: 0 1px 3px rgba(0, 0, 0, 0.4);
width: auto;
}
#cssmenu li {
margin: 0 5px;
padding: 0 0 8px;
float: left;
position: relative;
list-style: none;
}
#cssmenu a,
#cssmenu a:link {
font-weight: bold;
font-size: 13px;
color: #e7e5e5;
text-decoration: none;
display: block;
padding: 8px 20px;
margin: 0;
border-radius: 5px;
-webkit-border-radius: 5px;
-moz-border-radius: 5px;
text-shadow: 0 1px 1px rgba(0, 0, 0, 0.3);
}
#cssmenu a:hover {
background: #000;
color: #fff;
}
#cssmenu .active a,
#cssmenu li:hover > a {
background: #979797 url(images/overlay.png) repeat-x 0 -40px;
background: #666666 url(images/overlay.png) repeat-x 0 -40px;
color: #444;
border-top: solid 1px  #f8f8f8;
-webkit-box-shadow: 0 1px 1px rgba(0, 0, 0, 0.2);
-moz-box-shadow: 0 1px 1px rgba(0, 0, 0, 0.2);
box-shadow: 0 1px 1px rgba(0, 0, 0, 0.2);
text-shadow: 0 1px 0 #ffffff;
}
#cssmenu ul ul li:hover a,
#cssmenu li:hover li a {
  background: none;
  border: none;
  color: #666;
  -webkit-box-shadow: none;
  -moz-box-shadow: none;
}
#cssmenu ul ul a:hover {
background: #7d7d7d url(images/overlay.png) repeat-x 0 -100px !important;
color: #fff !important;
-webkit-border-radius: 5px;
-moz-border-radius: 5px;
border-radius: 5px;
text-shadow: 0 1px 1px rgba(0, 0, 0, 0.1);
}
#cssmenu li:hover > ul {
display: block;
}
#cssmenu ul ul {
z-index: 1000;
display: none;
margin: 0;
padding: 0;
width: 185px;
position: absolute;
top: 40px;
left: 0;
background: #ffffff url(images/overlay.png) repeat-x 0 0;
border: solid 1px #b4b4b4;
-webkit-border-radius: 5px;
-moz-border-radius: 5px;
border-radius: 5px;
-webkit-box-shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
-moz-box-shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
box-shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
}
#cssmenu ul ul li {
float: none;
margin: 0;
padding: 3px;
}
#cssmenu ul ul a,
#cssmenu ul ul a:link {
font-weight: normal;
font-size: 12px;
}
#cssmenu ul:after {
content: '.';
display: block;
clear: both;
visibility: hidden;
line-height: 0;
height: 0;
}
* html #cssmenu ul {
  height: 1%;
}

Answer 1

我不认为有问题，完全正常的行为。容器中没有足够的空间，最后一个元素排在第二行。如果您不希望发生这种情况，请设置 min-width:400px;到#cssmenu ul。但是由于#cssmenu 中有几个 ul，最好将单独的类放在最上面。