C.css

@CHARSET "UTF-8";
body
{
	margin:0;
	padding:0;
	font-family:sans-serif;
	background:url(http://dik.img.kttpdq.com/pic/2/802/3dc8ae30a4433bc8.jpg);
	background-size:cover;
}
.box
{
	position:absolute;
	top:20%;
	left:40%;
	transform:tranlate(-50%,-50%);
	width:400px;
	padding:40px;
	background:rgba(0,0,0,.8);
	box-sizing:border-box;
	box-shadow:0 15px 25px rgba(0,0,0,.5);
	border-radius:10px;
}
.box h2
{
	margin:0 0 30px;
	padding:0;
	color:#fff;
	text-align:center;
}
.box .inputBox
{
	position:relative;
}
.box .inputBOx input
{
	width:100%;
	padding:10px 0;
	font-size:15px;
	color:#fff;
	letter-spacing:3px;
	margin-bottom:30px;
	border:none;
	border-bottom: 1px solid #fff;
	outline:none;
	background:transparent;
}


.box .inputBox label
{
	position:absolute;
	top:0;
	left:0;
	letter-spacing:1px;
	padding:10px 0;
	font-size:16px;
	color:#fff;
	pointer-events:none;
	transition:.5s;
}
.box .inputBox input:focus~label,
.box .inputBox input:valid~label
{
	top:-18px;
	left:0;
	color:#03a9f4;
	font-size:12px;
}

.box input[type="submit"]
{
	background:transparent;
	border:none;
	outline:none;
	color:#fff;
	background:#03a9f4;
	padding:10px 45px;
	cursor:pointer;
	border-radius:5px;
	margin:10px;
	
}

.box input[type="button"]
{
	background:transparent;/*背景：全透明*/
	border:none;           /*边框样式*/
	outline:none;                
	color:#fff;            
	background:#03a9f4;
	padding:10px 45px;     /*按钮大小*/
	cursor:pointer;        /*光标样式*/
	border-radius:5px;     /*边框圆角*/
	margin:10px;
}
.box img
{
       align:center;
	margin:10px;
}