html, body {
	height: 100%;
}
.container {
	min-height: 91%;
}

.btn {
	width: 150px; 
	height: 150px;
	font-weight: bold;
}

.footer {
	position: auto;
	left: 0;
	bottom: -10px;
	width: 100%;
	background-color: #f5f5f5;
	text-align: center;
}