我这个代码里面的
div li{background: #545178;border-bottom:1px solid #fff ;}
div th{background: #515278;border-bottom:1px solid #fff ;}
第一个就能显示出来颜色，第二个显示不出来
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>折叠菜单</title>
<style>
ul{list-style: none;padding: 0;margin: 0;}
div{width: 100%;border: 1px solid #5d7851;margin: 1px;}
div li{background: #545178;border-bottom:1px solid #fff ;}
div td{background: #515278;border-bottom:1px solid #fff ;}
div li a{text-decoration: none;color: #fff;font-size: 16px;height: 40px;line-height: 63px;padding-left: 10px;}
div li a:hover{text-decoration: underline;}
.wrap {width: 100%;display: none;}
.wrap li{background: white;margin: 0;}
.wrap li a{color: #5f383a;font-size: 15px;}
#left{width: 40%;float: left;overflow: hidden;}
#right{width: 60%;float: left;margin-left: -10px;display: inline;overflow: hidden;}
</style>
<div id="left">
<div id="fold">
<ul>
<li>
<a href="#">鞋类</a>
<ul class="wrap">
<li><a href="#">经典老爹鞋</a></li>
<li><a href="#">新款帆布鞋</a></li>
</ul>
</li>
<li>
<a href="#">玩具类</a>
<ul class="wrap">
<li><a href="#">经典黄鸡玩偶</a></li>
<li><a href="#">新款小单车玩具</a></li>
</ul>
</li>
<li>
<a href="#">裤子类</a>
<ul class="wrap">
<li><a href="#">经典裤子</a></li>
<li><a href="#">新款皮裤</a></li>
</ul>
</li>
<li>
<a href="#">科技类</a>
<ul class="wrap">
<li><a href="#">经典苹果电脑</a></li>
<li><a href="#">新款菠萝手机</a></li>
</ul>
</li>
</ul>
</ul>
</div>
</div>
<div id="right">
<table border="1" cellspacing="73%" cellpadding="27%">
<thead>
<th><input type='checkbox'></th>
<th>商品</th>
<th>数量</th>
<th>单价</th>
<th>状态</th>
<th>库存</th>
<th>小计</th>
</thead>
