*{
	padding:0;
	margin:0;
	box-sizing: border-box;
}
body{
	width: 100%;
}
.black{
	width: 100%;
	background: black;
}

a{
	text-decoration: none;
	color: #fff;
}
img{
	vertical-align: bottom;
}
ul,ol{
	list-style:none;
}
button{
	border:none;
	outline: none;
	text-align: center;
}
input{
	border:none;
	outline: none;
}

/*清除浮动*/
.clear_float:after{
	content:"";
	display: block;
	clear: both;
}
/*单行文字超出隐藏*/
.pl_hidden{
	white-space: nowrap;
	overflow: hidden;
	text-overflow: ellipsis;
}
/*满屏固定定位*/
.full_fixed{
	position: fixed;
	width:100%;
	height:100%;
	top:0;
	left:0;
}
/*居中绝对定位*/
.center_absolute{
	position: fixed;
	top:50%;
	left:50%;
	transform: translate(-50%,-50%);
}
.nav{
	position: fixed;
	bottom:0;
	left:0;
	width:100%;
	background: #fff;
	border-top:1px solid #ddd ;
	height: 70px;
}
/*遮罩层*/
.mask{
	position: absolute;
	top: 0px;
	filter: alpha(opacity=70);
	background-color: #000;
	z-index: 50;
	left: 0px;
	opacity:0.4;
	-moz-opacity:0.4;
	display: none;
}