body {
    height: 100%;
	min-height: 500px;
    background-color: #ddd;
	box-sizing: border-box;
	font-family: Roboto, sans-serif;
}

.window {
    background: url(../images/1.jpg) center no-repeat;
	background-size: cover;
	height: 100vh;
	min-height: 500px;
	display: flex;
	justify-content: center;
	align-items: center;
}

.button {
	display: block;
	width: 100px;
	padding: 15px 40px;
	color: #fff;
	background-color: #2153b3;
	border-radius: 25px;
	text-decoration: none;
	text-align: center;
	text-transform: uppercase;
}