html, body {
	height: 100%;
	margin: 0;
}
#main_board {
	height: 100%;
	background: yellow;
}
#board {
	height: 100%;
	width: 100%;
}

.answer_1 {
	float: left;
	width: 50%;
	height: 50%;
}

.answer_2 {
	margin: auto;
	background: white;
	width: 200px;
}

.answer_btn {
	height: 25%;
}


.btnRight {
	background: green
}
.btnWrong {
	background: red;
}