/**
 * 导航练习1
 */
 body{
 background:#929292;
 }



#nav li{
list-style:none;
float:left;
margin:0;
padding:0;
}
a{
text-decoration:none;
text-align:center;
display:block;
padding:10px;

}
a:hover{
color:red;
background:#fff;

}

#nav ul{
background:linear-gradient(top center,#ddd,#fff);
position:absolute;
width:50px;
display:none;
margin:0;
padding:0;
border-bottom-left-radius:3px;
border-bottom-right-radius:3px;
}
#nav ul ul{
position:absolute;
left:48px;
top:50px;

}
#nav li:hover >ul{
display:block;
}
#nav>li{
background:linear-gradient(top center,#ddd,#fff);

}