<style type="text/css">
/* common styling */
/* set up the overall width of the menu div, the font and the margins */
.menu {
width:800px; 
margin:0; 
margin:50px 0;
}
/* remove the bullets and set the margin and padding to zero for the unordered list */
.menu ul {
padding:0; 
margin:0;
list-style-type: none;
}
/* float the list so that the items are in a line and their position relative so that the drop down list will appear in the right place underneath each list item */
.menu ul li {
float:left; 
position:relative;
}
/* 默认背景 */
.menu ul li a, .menu ul li a:visited {
display:block; 
text-align:center; 
text-decoration:none; 
width:96px; 
height:35px; 
color:#000; 
border:1px solid #fff;
border-width:0px 0 0 0;
background:; 
line-height:35px; 
font-size:14px;
}
/* make the dropdown ul invisible */
.menu ul li ul {
display: none;
}
/* 一级菜单默认背景 */
/* set the background and foreground color of the main menu li on hover */
.menu ul li:hover a {
color:#fff; 
background:#007DD8;
}
/* make the sub menu ul visible and position it beneath the main menu list item */
.menu ul li:hover ul {
display:block; 
position:absolute; 
top:35px; 
left:0; 
width:96px;
}
/*二级菜单默认背景*/
.menu ul li:hover ul li a {
display:block; 
background:#ECECEC; 
color:#000;
filter:alpha(Opacity=100);-moz-opacity:0.1;opacity: 1;
}
/* 二级菜单经过背景 */
.menu ul li:hover ul li a:hover {
background:#007DD8; 
color:#FFF;
}
</style>
