一模一样的代码，为什么我的LOGO看不到？
@charset "utf-8";
/* CSS Document */
.public-header{
height:120px;
}
.public-header .header-logo{
float:left;
margin-top:40px;
}
.public-header .header-logo .a{
width:182px;
height:54px;
background:url("../images/index-header-logo.png");
}
.public-header .header-nav{
float:right;
font-size:14px;
}
.public-header .header-nav .item{
float:left;
margin-top:44px;
margin-left:50px;
}
.public-header .header-nav .a{
color:#333;
}
.public-container{
position:relative;
margin:0 auto;
width:1100px;
}
.public-footer{
height:320px;
background:#F00;
}
