                        課程
                    
                        /前端開發(fā)
                        
                            /HTML/CSS
                        
                        /企業(yè)網(wǎng)站綜合布局實戰(zhàn)

求解啊，左邊插入的圓角圖片為什么跑到上面了啊，我看了距離對的啊

<!DOCTYPE?html>
<html>
<head>
<meta?charset="utf-8">
	<title>企業(yè)網(wǎng)站實例</title>
	<link?rel="stylesheet"?type="text/css"?href="main1.css">
</head>
<body>
<div?class="top">
	<div?class="top_content">
		<ul>
			<li><a?href="#">加入收藏</a></li>
			<li><a?href="#">聯(lián)系我們</a></li>
			<li><a?href="#">設(shè)為首頁</a></li>
		</ul>	
	</div>	
</div>
<!--頁面頂端top結(jié)束-->

<div?class="wrap">
	<div?class="logo">
		<div?class="logo_left">
			<img?src="images/logo.jpg"?/>
		</div>
		<div?class="logo_right">
			<img?src="images/tel.jpg"?/>24小時服務(wù)熱線：<span?class="tel">123-456-7890</span>
		</div>
	</div>
	<!--logo結(jié)束-->

	<div?class="nav">
		<div?class="nav_left"></div>
		<div?class="nav_mid">
			<div?class="nav_mid_left">
				<ul>
					<li><a?href="#">首頁</a></li>
					<li><a?href="list.html">關(guān)于慕課</a></li>
					<li><a?href="list.html">新聞動態(tài)</a></li>
					<li><a?href="list.html">課程中心</a></li>
					<li><a?href="list.html">在線課程</a></li>
					<li><a?href="list.html">人才招聘</a></li>
				</ul>
			</div>
			<!--nav_mid_left結(jié)束-->
			<div?class="nav_mid_right">
				<form?action=""?method="post">
					<input?type="text"?class="search_text"?/>
				</form>
			</div>
			<!--nav_mid_right結(jié)束-->
		</div>
		<!--導(dǎo)航主體nav_mid結(jié)束-->
		<div?class="nav_right"></div>		
	</div>
	?<!--nav結(jié)束-->
</div>
</body>
</html>

*{
	padding:?0px;
	margin:?0px;
	font-size:?12px;
}
body{
	background-color:?#F5F5F5;
}
.top{
	width:?100%;
	height:27px;
	background:?url(images/top_bg.jpg)?repeat-x;
}
.top_content{
	width:?1000px;
	line-height:?27px;
	margin:?0?auto;	
}
.top_content?li{
	float:?right;
	width:?70px;
	list-style-image:?url(images/arrow.jpg);
}
.top_content?a:link,.top_content?a:visited{
	color:?#8E8E8E;
	text-decoration:none;
}
.top_content?a:hover,.top_content?a:active{
	color:?#C00;
	text-decoration:none;
}
.wrap{
	margin:?0?auto;
	width:?1000px;
}
.logo{
	height:?80px;
	background-color:?#FFF;?
}
.logo_left{
	width:375px;
	display:inline;
	float:?left;
}
.logo_right{
	display:inline;
	height:?28px;
	width:?300px;
	float:?right;
	color:?#8E8E8E;
	margin-top:?30px;
}
.logo_right?img{
	margin-right:10px;
	vertical-align:?middle;?
}
.tel{
	font-size:?22px;
	color:?#C00;
	font-family:?"微軟雅黑";
}
.nav{
	height:?40px;
}
.nav_left{
	width:?10px;
	background:?url(nav_left.jpg)?no-repeat;
}
.nav_mid{
	width:?980px;
	background:?url(images/nav_bg.jpg)?repeat-x;
	line-height:?40px;
}
.nav_right{
	width:?10px;
	background:?url(images/nav_right.jpg)?no-repeat;
}
?.nav_left,?.nav_mid,?.nav_right{
	height:?40px;
	display:?inline;
	float:?left;
}
.nav_mid?li{
	float:?left;
	list-style-type:?none;
	width:?100px;
	text-align:?center;
	font-family:?"微軟雅黑";
}
.nav_mid?a:link,?.nav_mid?a:visited{
	font-size:?16px;
	color:?#FFF;
	text-decoration:?none;
}
.nav_mid?a:hover,?.nav_mid?a:active{
	font-size:?16px;
	color:?#FF0;
	text-decoration:?none;
}
.nav_mid_left{
	width:?680px;
	float:left;
}
.nav_mid_right{
	width:?300px;
}
.nav_mid_left,?.nav_mid_right{
	display:?inline;
}
.search_text
{
	width:?190px;
	float:?left;
	height:?25px;
	margin-top:?5px;
	background:url(images/search.jpg)?no-repeat?right?center;
}