html {
	height: 100%;
	width: 100%;
}
.btn {
    padding: 10px 20px;
    font-size: 16px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
	background-color: #a9a9a9;
}
.on {
    background-color: #4CAF50;
    color: white;
}
.off {
	background-color: #f44336;
	color: white;
}