Please solve my navigation problem. It's a small problem. Please give me an expert_html/css_WEB-ITnose

*{
margin: 0;
padding: 0;
list-style:none;
}
.nav_1{
border-radius: auto;
box-shadow: 10px 10px 5px #888888;
text-align: right;
height: 50px;
margin-top: 50px;
margin-right: auto;
margin-bottom: 50px;
margin-left: auto;
background-color: #930;
}
.nav_1>ul{
display: inline-block;
list-style: none;
position: relative;
width: 960px;
margin-top: 0;
margin-right: auto;
margin-bottom: 0;
margin-left: auto;
text-align: center;
}
.nav_1>ul>li>a{
display: block;
width: 105px;
color: #FFFFFF;
text-align: center;
text-decoration: none;
background-color: #930;
}
.nav_1>ul>li{
line-height: 50px;
display: inline-block;
margin-right: auto;
margin-left: auto;
float: left;
font-family: "新宋体";
font-weight: bold;
}
.nav_1>ul>li>ul{
list-style: none;
display: none;

}
.nav_1>ul>li>ul>li{
display: block;
line-height: 25px;
}
.nav_1>ul>li>ul>li>a{

border-radius:55px;
display: block;
width: 100px;
color: #FFFFFF;
text-align: center;
text-decoration: none;
background-image: url(red flash 11.png);
line-height: 40px;
background-position: center center;
}
.nav_1>ul>li:hover>ul{
display: block;
}

.nav_1 li a:hover{
color: #000;
}
.nav_1 li ul li a:hover{
color: #ff0;
background-color: #000;
}
.nav_1 ul li a.thisclass{
border-radius:55px;
text-decoration: none;
background-color: #CF0;
}


<script> <br> $(function(){ <br> var nav_1 = $(".nav_1 a"); <br> nav_1.click(function(){ <br> $(this).addClass("thisclass").siblings().removeClass("thisclass"); <br> }); <br> }); <br> </script>

主页
         

           
• 二级栏目

  
         
• 二级栏目

         

  

音乐
         

         
• 二级栏目


         
• 二级栏目

         

  

视频
          

• Second-level column



🎜>                                                                                                      ="#">Secondary column
                                          ">About
                                                           🎜>                                                                                                                          /ul>

My navigation focus clicks on other It will cause other backgrounds to change. The previous one will not disappear. When I need to click on music, the homepage disappears. When I click on a video, the music disappears. How to solve it???? Plan)

Someone please come! ! !

$(function(){
var nav_1 = $(".nav_1 a");
nav_1.click(function(){
$(this).closest("ul ").children("li").children("a").removeClass("thisclass");
$(this).addClass("thisclass");
});
}) ;