.a{
	background-size:cover;
	background-image: url(../img/口罩背景2.jpg);
	height: 700px;
	width: 1300px;
	margin: 0;
}
.b{
	width: 950px;
	height: 46px;
	padding-top: 100px;
	padding-left: 100px;
	color: white;
	text-align: center;
}
h1{
	font-size: 3em;
}
.c{
	border: 1;
	height: 300px;
	width: 300px;
	border-radius: 15px;
	background-color: #1c4557;
	opacity:0.7;
	margin-left:100px;
	margin-top: 100px;
}
.c1{
	text-align: center;
	font-size: 2em;
	padding-top:20px ;
	color: white;
}
.c2{
	width: 100xp;
	height: 20px;
	background-image: url(../img/usr.jpg) ;
	background-repeat: no-repeat;
	margin-top: 20px;
	margin-left: 50px;
	padding-left: 25px;
	font-size: 16px;
}
.c3{
	width: 100xp;
	height: 20px;
	background-image: url(../img/password.jpg) ;
	background-repeat: no-repeat;
	margin-top: 20px;
	margin-left: 50px;
	padding-left: 25px;
	font-size: 16px;
}
.c4{
	border:0px;
    width: 130px;
    height:20px;
    background-color: #127adc;
    font-size:16px;
    color:#FFFFFF;
    border-radius: 5px;
	margin-top: 40px;
}