.about_us_content{
	height: auto!important;
}
.content .about_img{
	width: 100%;
	position: relative;
}
.content .about_img>img{
	width: 100%;
	height: auto;
}
.content .about_img .welcome{
	width: 100%;
	position: absolute;
	top: 50%;
	left: 50%;
	/*当使用：top: 50%;left: 50%;， 是以左上角为原点，故不处于中心位置*/
    /*translate(-50%,-50%) 作用是，往上（x轴）,左（y轴）移动自身长宽的 50%，以使其居于中心位置*/
    transform: translate(-50%,-50%);
    -webkit-transform: translate(-50%,-50%); 
    -ms-transform: translate(-50%,-50%);
    -moz-transform: translate(-50%,-50%);
    -o-transform: translate(-50%,-50%);
	z-index: 33;
	text-align: center;
	color: #fff;
}
.content .about_img .welcome>span:nth-child(1){
	display: block;
	font-family: 'Roboto Condensed';
    letter-spacing: 3px;
    margin-bottom: 10px;
    font-weight: 700;
}
.content .about_img .welcome>span:nth-child(2){
	display: block;
	font-size: 40px;
	font-weight: 700;
}
.content .about_tab{
	width: 100%;
	height: 70px;
	background-color: #333836;
}
.content .about_tab .about_nav{
	width: 700px;
	height: 100%;
	margin: 0 auto;
}
.content .about_tab .about_nav>div{
	display: inline-block;
	width: 49%;
	line-height: 70px;
	text-align: center;
	color: #828a8f;
	font-weight: 700;
	font-size: 15px;
	cursor: pointer;
}
.content .about_tab .about_nav>div:hover{
	color: #fff;
}
.content .about_tab .about_nav .active{
	color: #fff!important;
}
.content .about_main{
	width: 700px;
	margin: 0 auto;
	padding: 90px 0 40px 0;
}
.content .about_main .main h2{
	font-size: 24px;
}
.content .about_main .main>p{
	font-size: 16px;
	font-family: 'Open Sans';
    padding-top: 12px;
    padding-bottom: 12px;
    color: #333836;
    line-height: 2;
}
.content .about_main .main>p>span{
	font-weight: 700;
}
.content .about_main .main .main_imgs{
	width: 100%;
}
.content .about_main .main .main_imgs>img{
	width: 32%;
	height: 200px;
	display: inline-block;
	margin-right: 5px;
	margin-bottom: 8px;
}
.content .about_main .main_2{
	display: none;
}