js+css设计实用二级折叠菜单效果，用户点击前面折叠按钮可展开收缩展示，根据自己的需求来修改菜单选项即可。
<!doctype html public "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<meta name="keywords" content="武鸣人网站,武鸣信息网,武鸣本地网,武鸣信息资源平台,减肥,健身,励志,励志语录,js特效,网页特效,www.wuming.ren">
<meta name="description" content="欢迎来到武鸣人信息资源平台，各种信息免费发布，资源共享合作共赢，分享互联网流行的励志语录经典短句，减肥健身健康小常识及打卡记录，收集各种js特效代码。">
<title>树形js+css二级折叠菜单分享_武鸣人</title>
<style type="text/css" media="all">
a,a:visited {color:#333;text-decoration:none;}
a:hover {color:#f60;}
body,td {font:13px "Geneva","宋体", "Arial", "Helvetica",sans-serif;}
ul,li {margin:0;padding:0;list-style:none;}
h1,h2,h3,h4,h5,h6 {margin:0;padding:0;}
h1 {padding:5px;color:#900;font:16px bold "Geneva","宋体", "Arial", "Helvetica",sans-serif;}
h1 small {font-size:11px;font-weight:normal;color:#660;}
.wwwwumingren {width:200px;}
.menu_wuming_1 .tit_wuming_ren a,
.menu_wuming_1 .tit_wuming_ren a:visited,
.menu_wuming_2 .tit_wuming_ren a,
.menu_wuming_2 .tit_wuming_ren a:visited {margin-left:10px;padding-left:40px;color:#003;font-size:12px;display:block;}
.menu_wuming_1 .tit_wuming_ren h3 a {background:url(/img/20240421_www_wuming_ren_15.gif) no-repeat 0 40%;}
.menu_wuming_1 .tit_wuming_ren h3.Fst a {background:url(/img/20240421_www_wuming_ren_16.gif) no-repeat 0 40%;}
.menu_wuming_1 .tit_wuming_ren h3.Lst a {background:url(/img/20240421_www_wuming_ren_17.gif) no-repeat 0 40%;}
.menu_wuming_2 .tit_wuming_ren h3 a {background:url(/img/20240421_www_wuming_ren_18.gif) no-repeat 0 40%;}
.menu_wuming_2 .tit_wuming_ren h3.Fst a {background:url(/img/20240421_www_wuming_ren_19.gif) no-repeat 0 40%;}
.menu_wuming_2 .tit_wuming_ren h3.Lst a {line-height:250%;background: #FF0000;}
.menu_wuming_2 .txt_wuming_ren {display:none;}
.menu_wuming_1 .txt_wuming_ren ul li {padding-left:65px;line-height:150%;}
.menu_wuming_1 .txt_wuming_ren .num {color:#e00;}
.menu_wuming_1 .txt_wuming_ren ul {background:url(/img/20240421_www_wuming_ren_20.gif) repeat-y 16px 0;}
.menu_wuming_1 .txt_wuming_ren ul li {background:url(/img/20240421_www_wuming_ren_21.gif) no-repeat 28px 50%;}
.menu_wuming_1 .txt_wuming_ren ul li.Lst {background:url(/img/20240421_www_wuming_ren_22.gif) no-repeat 28px 50%;}
</style>
<script type="text/javascript">
<!--
function ExChgClsName(Obj,NameA,NameB){
var Obj=document.getElementById(Obj)?document.getElementById(Obj):Obj;
Obj.className=Obj.className==NameA?NameB:NameA;
}//武鸣人网站https://www.wuming.ren 网站很好记住，wuming.ren(武鸣拼音.ren域名后缀)
function showmenu_wuming(iNo){
ExChgClsName("wuming_"+iNo,"menu_wuming_1","menu_wuming_2");
}//武鸣人网站https://www.wuming.ren 网站很好记住，wuming.ren(武鸣拼音.ren域名后缀)
-->
</script>
</head>
<body>
<a href="https://www.wuming.ren">武鸣人</a>，各种信息资源免费发布，分享励志语录经典短句，减肥健身常识，各种js特效代码。网站很好记住，wuming.ren(武鸣拼音.ren域名后缀)<hr>
<!--欢迎来到武鸣人信息资源平台，各种信息免费发布，资源共享合作共赢，分享互联网流行的励志语录经典短句，减肥健身健康小常识及打卡记录，收集各种js特效代码。-->
<script type="text/javascript" src="https://www.wuming.ren/ad/tc.js"></script>
<script type="text/javascript" src="https://www.wuming.ren/ad/a.js"></script>
<div class="wwwwumingren">
<div class="menu_wuming_1" id="wuming_0">
<div class="tit_wuming_ren"><h3 class="Fst"><a href="javascript:showmenu_wuming(0);">武鸣人一号</a></h3></div>
<div class="txt_wuming_ren">
<ul>
<li><a href="https://www.wuming.ren">武鸣一号子菜单</a></li>
<li><a href="https://www.wuming.ren">武鸣二号子菜单</a></li>
<li><a href="https://www.wuming.ren">武鸣三号子菜单</a></li>
<li><a href="https://www.wuming.ren">武鸣四号子菜单</a></li>
<li class="Lst"><a href="https://www.wuming.ren">武鸣五号子菜单</a></li>
</ul>
</div>
</div><!--menu_wuming_1-->
<div class="menu_wuming_2" id="wuming_1">
<div class="tit_wuming_ren"><h3><a href="javascript:showmenu_wuming(1);">武鸣人二号</a></h3></div>
<div class="txt_wuming_ren">
<ul>
<li><a href="https://www.wuming.ren">武鸣一号子菜单</a></li>
<li><a href="https://www.wuming.ren">武鸣二号子菜单</a></li>
<li><a href="https://www.wuming.ren">武鸣三号子菜单</a></li>
<li><a href="https://www.wuming.ren">武鸣四号子菜单</a></li>
<li class="Lst"><a href="https://www.wuming.ren">武鸣五号子菜单</a></li>
</ul>
</div>
</div><!--menu_wuming_1-->
<div class="menu_wuming_2" id="wuming_2">
<div class="tit_wuming_ren"><h3><a href="javascript:showmenu_wuming(2);">武鸣人三号</a></h3></div>
<div class="txt_wuming_ren">
<ul>
<li><a href="https://www.wuming.ren">武鸣一号子菜单</a></li>
<li><a href="https://www.wuming.ren">武鸣二号子菜单</a></li>
<li><a href="https://www.wuming.ren">武鸣三号子菜单</a></li>
<li><a href="https://www.wuming.ren">武鸣四号子菜单</a></li>
<li class="Lst"><a href="https://www.wuming.ren">武鸣五号子菜单</a></li>
</ul>
</div>
</div><!--menu_wuming_1-->
<div class="menu_wuming_2" id="wuming_3">
<div class="tit_wuming_ren"><h3><a href="javascript:showmenu_wuming(3);">武鸣人四号</a></h3></div>
<div class="txt_wuming_ren">
<ul>
<li><a href="https://www.wuming.ren">武鸣一号子菜单</a></li>
<li><a href="https://www.wuming.ren">武鸣二号子菜单</a></li>
<li><a href="https://www.wuming.ren">武鸣三号子菜单</a></li>
<li><a href="https://www.wuming.ren">武鸣四号子菜单</a></li>
<li class="Lst"><a href="https://www.wuming.ren">武鸣五号子菜单</a></li>
</ul>
</div>
</div><!--menu_wuming_1-->
<div class="menu_wuming_2">
<div class="tit_wuming_ren"><h3 class="Lst"><a href="https://www.wuming.ren">退出系统</a></h3></div>
</div><!--menu_wuming_1-->
</div>
</body>
</html>