css設置前一個兄弟節點

css需求分析:鼠標移到“企業采購”改變顏色 有個下拉框 解決思路：對於相鄰節點少的情況下可以將節點書寫順序顛倒，然後在有排序就好啦，

#head_enter{
 position: relative;
}
#enter{
 text-align: center;
 height: 31px;
 padding: 0 8px;




 border: 1px solid transparent;
 box-sizing: border-box;
 position: relative;
}
#enter_open{
 width: 156px;
 height: 95px;
 margin-top: 30px;
 position: absolute;
 border: 1px solid #ccc;
 border-top: none;
 display: none;
}
#enter:hover{
 background-color: white;
 border: 1px solid #ccc;
 border-bottom: none;
}
#enter_parent{
 position: relative;
}
#enter_parent:hover>#enter_open{
 display: block;
}
#enter_open:hover+#enter{
 border: 1px solid #ccc;
 border-bottom: none;
 background-color: white;
}
#foot_enter{
 position: relative;
}
#enter_li1{
 display: block;
 display: flex;
 justify-content: space-between;
 padding: 0 15px;
 box-sizing: border-box;
}
#enter_li2{
 display: block;
 display: flex;
 justify-content: space-between;
 padding: 0 40px 0 15px;
 box-sizing: border-box;




}

<li id="head_enter">
 <div id="enter_parent">
 <div id="enter_open">
 <ul id="foot_enter">
 <div id="enter_li1">
 <li class="enter_li"><a href="">企業購</a></li>
 <li class="enter_li"><a href="">商用場景館</a></li>
 </div>
 <div id="enter_li2">
 <li class="enter_li"><a href="">工業品</a></li>
 <li class="enter_li"><a href="">禮品卡</a></li>
 </div>
 <div id="enter_li1">
 <li class="enter_li"><a href="">豐客多商城</a></li>
 </div>
 </ul>
 </div>
 <div id="enter">
 <a class="color_red" href="">企業采購</a>
 
 </div>
 </div>
 </li>