遮罩效果弹出层

.guize_html {
	position:fixed;
	top:25%;
	left:50%;
	margin-top:-80px;
	margin-left:-300px;
	width:660px;
	height:auto;
	border-radius:4px;
	background-color:#fff;
	color:#000;
	text-align:center;
	font-size:14px
}
.guize_html p {
	padding:0 10px;
	text-align:left;
	text-indent:2em
}
.btn {
	display:block;
	margin:30px auto;
	width:240px;
	height:40px;
	border-radius:4px;
	background-color:#ff6434;
	color:#fff;
	text-align:center;
	line-height:40px;
	cursor:pointer
}
.overfloat {
	position:fixed;
	line-height:25px;
	top:0;
	left:0;
	z-index:9;
	display:none;
	width:100%;
	height:100%;
	background-color:rgba(1,1,1,.5)
}