*{
	margin:0;
	padding:0;}
.menu_left {
    width: 280px;
    float: left;
}
.left_nav {
    width: 280px;
    height: 800px;
    background-color:#3c3c3c;
    text-align: center;
}
.conter_txt {
    float: right;
    width: 840px;
    margin-right: 40px;
    margin-top: 10px;
}
.warp{
	width:1200px;
	height:800px;}

.menu_nav ul li {
    display: inline-block;
	height:50px;
    margin-top: 10px;
    width: 280px;
	background:#282828;
    /* background: #ffd800; */
    list-style: none;
    overflow: visible;
}
.menu_nav ul li a{
	font-size:20px;
	color:#fff;
	line-height:50px;}
	
.menu_nav ul .active{
	background:#48bed8;
	}	
.conter_txt p{
	text-indent:2em;
	line-height:40px;
	font-size:18px;}