hover不起作用<body><divclass="top_con"><divclass="top_bar"><divc

<body>

<div class="top_con">
<div class="top_bar">
<div class="welcome fl">欢迎来到天天生鲜!</div>
<div class="usr_center fr">
<div class="usr_info fl">欢迎您：<em>张山</em>
</div>
<ul class="load_regi fl">
<li><a href="#"></a>登录</li>
<li><span>|</span></li>
<li><a href="#"></a>注册</li>
</ul>
<ul class="usr_other fl">
<li><span>|</span></li>
<li><a href="#"></a>我的购物车</li>
<li><span>|</span></li>
<li><a href="#"></a>我的订单</li>
</ul>
</div>
</div>
</div>
</body>

.top_con{
height: 29px;
background-color: #f9f9f9;
border-bottom: 1px solid #fafafa;
color: #666;
}

.top_bar{
height: 29px;
width: 1200px;
font: normal 12px/29px 'microsoft Yahei';
margin: 0 auto;
}

.welcome{
height: 29px;
padding-left: 40px;
}

.usr_center{
height: 29px;
padding-right: 40px;
font-size: 0px;
}

.usr_info{
display: none;
/* 父级将font_size设定为0px了，在这里必须先设定为正常值才能显示 */
font-size:12px;
}

.usr_info em{
color: #f80;
}

.load_regi li,.usr_other li{
display: inline-block;
font-size: 12px;
}

.load_regi li span,.usr_other li span{
padding: 0 15px;
color: #666
}

.load_regi a:hover,.usr_other a:hover{

color: #f80;

}

最后的hover不起作用，麻烦大家帮我看看问题出在哪里？