jquery實(shí)現(xiàn)下拉菜單的手風(fēng)琴效果

<div class="site-nav">
 <ul class="site-accordion">
 <li>
 <div class="tab-head">學(xué)科領(lǐng)域</div>
 <ul class="tabs-list">
 <li>機(jī)械電子</li>
 <li>生物工程</li>
 <li>能源環(huán)保</li>
 <li>化學(xué)化工</li>
 </ul>
 </li>
 <li>
 <div class="tab-head">省份地區(qū)</div>
 <ul class="tabs-list">
 <li>陜西省</li>
 <li>江蘇省</li>
 <li>山東省</li>
 <li>河南省</li>
 </ul>
 </li>
 <li>
 <div class="tab-head">經(jīng)費(fèi)范圍</div>
 <ul class="tabs-list">
 <li>50萬~100萬</li>
 <li>100萬~200萬</li>
 <li>200萬~500萬</li>
 <li>500萬以上</li>
 </ul>
 </li>
 <li>
 <div class="tab-head">需求狀態(tài)</div>
 <ul class="tabs-list">
 <li>狀態(tài)1</li>
 <li>狀態(tài)2</li>

 </ul>
 </li>

 </ul>
</div>

.site-accordion>li{
 margin-top: 13px;
}
.site-accordion>li .tab-head{
 width: 160px;
 height: 40px;
 line-height: 40px;
 text-align: center;
 color: #9c9c9c;
 font-size: 16px;
 background: #f2f2f2;
}
.site-accordion>li .tab-head:hover{
 background: #292d48;
}
.site-accordion>li .tab-head:after{
 content: '';
 border: 5px solid #4F5160;
 border-color: #4F5160 transparent transparent transparent;
 margin-top: 20px;
 position: relative;
 top: 10px;
 left: 5px;
}
.site-accordion>li .tabs-list{
 display: none;
}
.site-accordion>li .tabs-list li{
 width: 160px;
 height: 40px;
 line-height: 40px;
 text-align: center;
 color: #9c9c9c;
.site-accordion>li .tabs-list li:hover{
 background: #f2f2f2;
} 

$('.tab-head').click(function(){
 $(this).next().slideToggle();
 $('.tab-head').css('background','#FFFFFF');
 $(this).css('background','#292d48');

 })