请问如何修改导航下拉菜单的背景颜色 [复制链接]

我样式是
/*网站基础样式*/
body,div,ul,li,table,p,h1,form,legend,fieldset,input button,select,textarea,button{margin:0px;padding:0px;font-family:inherit;font-size:inherit;}
ul,li{list-style:none;}
table{border-collapse:collapse;border-spacing:0;}
a{color333333;text-decoration:none;}
a:hover{color176DB6;text-decoration:none;}

body{word-wrap:break-word;text-align:center;font:12px/20px Verdana,Helvetica,Arial,sans-serif;color333333;background:url(images/bj.jpg) repeat 0 0}
.page_style{width:960px;margin:0px auto 0px auto;padding:0 8px 0 8px;text-align:center;background:url(images/page_bg.gif) no-repeat 0 0;overflow:hidden;}
.clear{clear:both;font-size:0px;height:0px;line-height:0px;width:0px;margin:0 0 0 0;padding:0 0 0 0;overflow:hidden}


/*menu样式*/

.menu_box{clear:both;width:100%;}

                  /**********LOGO在上方样式***********/
.menu_box_style1_1{clear:both;border:0 solid #cccccc;}
.menu_box_style1_1_1{float:left;}
.menu_box_style1_1_2{float:right;padding:5px 0 0 0;}
.menu_box_style1_2{clear:both;text-align:left;height:33px;background:url(images/menubg.jpg) repeat 0 0;padding:11px 0 0 15px;}

.menu_style_1_first{float:left;width:100px;height:33px;text-align:center;background:url(images/menu_style_1.jpg) no-repeat right 0;}
.menu_style_1{float:left;width:100px;height:33px;text-align:center;background:url(images/menu_style_1.jpg) no-repeat right 0;}

a.menu_1nk{display:block;width:100px;height:25px;colorffffff;text-decoration: none;font-weight:bold;paddingpx 0 0 0}
a.menu_1:visited {display:block;width:100px;height:25px;colorffffff;text-decoration:none;font-weight:bold;paddingpx 0 0 0}
a.menu_1:hover {display:block;width:100px;height:25px;colorffffff;text-decoration:none;font-weight:bold;paddingpx 0 0 0;background:url(images/menu_style_1_out.jpg) no-repeat 0 0;}

a.menu_current_1{display:block;width:100px;height:25px;colorffffff;text-decoration:none;font-weight:bold;paddingpx 0 0 0;background:url(images/menu_style_1_out.jpg) no-repeat 0 0;}

                  /**********LOGO在左侧样式***********/
.menu_box_style2_1{border:0 solid #cccccc;text-align:right;padding:5px 2px 5px 0}
.menu_box_style2_2{clear:both;height:50px;background:url(images/menu_style_2_bg.gif) no-repeat 0 25px;}
.menu_box_style2_2_1{float:left;width:300px;height:50px;overflow:hidden;text-align:left}
.menu_box_style2_2_2{float:right;width:660px;padding:14px 0 0 0;height:36px;padding:0 0 0 0;text-align:right;overflow:hidden;}

.menu_style_2_first{float:left;width:100px;height:36px;text-align:center;}
.menu_style_2{float:left;width:100px;height:36px;text-align:center;background:url(images/menu_style_1.jpg) no-repeat 0 0;}

a.menu_2nk{display:block;width:100px;height:28px;color333333;text-decoration: none;font-weight:bold;paddingpx 0 0 0}
a.menu_2:visited {display:block;width:100px;height:28px;color333333;text-decoration:none;font-weight:bold;paddingpx 0 0 0}
a.menu_2:hover {display:block;width:100px;height:28px;color333333;text-decoration:none;font-weight:bold;paddingpx 0 0 0;background:url(images/menu_style_1_out.gif) no-repeat 0 0;}

a.menu_current_2{display:block;width:100px;height:28px;color333333;text-decoration:none;font-weight:bold;paddingpx 0 0 0;background:url(images/menu_style_1_out.gif) no-repeat 0 0;}


/*banner样式*/

.banner_box{padding:0 0 4px 0;margin:0 0 0 0;backgroundffffff url(images/banner_bg.gif) repeat-x left bottom;width:100%}
.banner_small_box{padding: 0 0 3px 0;margin:0 0 0 0;}


/*栏目布局样式*/

.lanmu_box{clear:both;margin:0 0 0 0;background-colorffffff;overflow:hidden;}

.lanmu_box_style1{clear:both;margin:0 0 0 0;backgroundffffff url(images/line_bg.jpg) repeat-y 0 0;height:100%;overflow:hidden;}
.lanmu_box_style1_left{float:left;width:235px;margin:0 0 0 0;overflow:hidden;text-align:left;}
.lanmu_box_style1_right{float:right;width:725px;margin:0 0 0 0;overflow:hidden;text-align:left;}
.lanmu_box_style1_clear{clear:both;font-size:0px;height:0px;line-height:0px;width:0px;margin:0 0 0 0;padding:0 0 0 0;overflow:hidden}

.lanmu_box_style2{clear:both;margin:0 0 0 0;backgroundffffff url(images/line_bg_2.jpg) repeat-y right top;height:100%;overflow:hidden;}
.lanmu_box_style2_left{float:left;width:725px;margin:0 0 0 0;overflow:hidden;text-align:left;}
.lanmu_box_style2_right{float:right;width:235px;margin:0 0 0 0;overflow:hidden;text-align:left;}
.lanmu_box_style2_clear{clear:both;font-size:0px;height:0px;line-height:0px;width:0px;margin:0 0 0 0;padding:0 0 0 0;overflow:hidden}

.lanmu_box_style3{clear:both;margin:0 0 0 0;backgroundffffff url(images/line_bg_3.jpg) repeat-y 0 0;height:100%;overflow:hidden;}
.lanmu_box_style3_left{float:left;width:235px;margin:0 0 0 0;overflow:hidden;text-align:left;}
.lanmu_box_style3_middle{float:left;width:490px;margin:0 0 0 0;overflow:hidden;text-align:left;}
.lanmu_box_style3_right{float:right;width:235px;margin:0 0 0 0;overflow:hidden;text-align:left;}
.lanmu_box_style3_clear{clear:both;font-size:0px;height:0px;line-height:0px;width:0px;margin:0 0 0 0;padding:0 0 0 0;overflow:hidden}


/*栏目导航样式*/
.nav_box{clear:both;width:100%;margin:0 0 10px 0;overflow:hidden;}
.nav_sign{float:left;text-align:left;font-size:14px;font-weight:bold;color186CB5;padding:12px 0 0 35px;background:url(images/nav_sign.jpg) no-repeat 10px 10px}
.nav_more{float:right;font-weight:normal;paddingpx 10px 0 10px;margin:0 0 0 0;background:url(public/more_icon.gif) no-repeat 0 13px;}
.nav_more a{line-height:15px;font-size:10px;}
.nav_title{height:40px;text-align:left;background:url(images/nav_titlebg.jpg) repeat-x 0 0;cursor:pointer;overflow:hidden;}
.nav_header{text-align:left;padding:0 0 0 0;margin:0 0 0 0}

.nav_content{margin:0 0 0 0;padding:5px 5px 5px 5px;border:0px solid #cccccc;text-align:left;}

/*修改导航样式*/
.nav_menu_list{text-align:left;border:0 solid #cccccc;padding:5px 5px 0 15px;margin:2px 0 5px 0;background:url(images/lanmu_nav_menu_bg.gif)  no-repeat 0 0;}
.nav_submenu_list{margin:5px 0 0 0;text-align:left;padding:0 5px 0 20px;background:url(images/lanmu_nav_submenu_bg.gif)  no-repeat 3px 0;}
a.nav_menu_href{text-align:left;}
a.nav_submenu_href{text-align:left;}

.nav_list{margin:0 0 0 0;padding:5px 5px 5px 5px;border:0px solid #cccccc;text-align:left;overflow:hidden;}
.nav_list_style_1{text-align:left;border:0 dotted #cccccc;border-width:0 0 0 0;padding:5px 0 0 12px;background:url(images/article_arrow.gif)  no-repeat 5px 14px;}
.nav_list_style_2{text-align:center;border:0 solid #cccccc;margin:5px 0 5px 0;}
.nav_list_date{padding:0 0 0 5px;}
.nav_list_image{margin:0 5px 5px 0;border:1px solid #dddddd;}
a.nav_list_title{text-align:left;}

.nav_list_tj_box{clear:both;padding:0 0 5px 0;margin:0 0 5px 0;text-align:left;border:0 dotted #dddddd;border-width:0 0 1px 0;width:100%;overflow:hidden;}
.nav_list_tj_content{overflow:hidden}
.nav_list_tj_image{float:left;margin:0 0 0 0;margin:5px 15px 5px 5px;}
a.nav_list_tj_title{text-align:left;height:20px;font-weight:bold;}