Class selectors and using pseudo class selectors with

The fact proved that , pure CSS You can't do that , Give it up , my HTML The code is as follows

<div class="banner">
			<aside>
				<h3> Taobao service </h3><a> more ></a>
				<ul></ul>
				<h4><div class="icon"></div> shopping </h4>
				<ul>
					<li> Auctions </li>
					<li> Flea Street </li>
					<li> Gold coins </li>
					<li> Trial Center </li>
					<li> e-book </li>
					<li> Buy... All over the world </li>
				</ul>
				<br />
				<h4><div  class="icon"></div> life </h4>
				<br />
				<ul>
					<li> lottery </li>
					<li> Cinema ticket </li>
					<li> insurance </li>
					<li> video </li>
					<li> Hydropower coal </li>
					<li> conduct financial transactions </li>
					<li> Medical Museum </li>
				</ul>
				<br />
				<h4><div  class="icon"></div> Interaction </h4>
				<br />
				<ul>
					<li> Love shopping </li>
					<li> Stubborn rabbit </li>
					<li> cyber model </li>
					<li> Taodoll </li>
					<li> LOHAS +</li>
					<li>U standing </li>
				</ul>
				<br />
				<h4><div  class="icon"></div> Tools </h4>
				<br />
				<ul>
					<li> Ali Wangwang </li>
					<li> Alipay </li>
					<li> browser </li>

				</ul>
				<br />
				<h4><div  class="icon"></div> other </h4>
				<br />
				<ul>
					<li> Good infinite </li>
					<li> One museum in one city </li>
					<li> Brand Specials </li>
					<li> Brand Street </li>
					<li> Brand group purchase </li>
					<li> Original by tmall </li>
				</ul>
			</aside>

CSS The code is as follows

.icon{
	height: 20px;
	width: 20px;
	display: inline-block;
}
.banner h4 > div:nth-child(2){
	background: url(../img/icon.png) no-repeat fixed ;
	
}
.icon:nth-child(2){
	background: url(../img/icon.png) no-repeat fixed ;
}

Use class to reuse nth-child(1) All elements that have been selected by the class selector will be selected , use nth-child（2） Words , You can't choose any of them