html, body {
	padding: 0;
	margin: 0;
}
.wrapper_plitka {
	height: 100%;
	min-height: 550px;
	margin: 0 auto;
	border: 10px solid blue;
	box-sizing: border-box;
	padding-top: 10px;
}


#image2, #image3, #v11, #v12, #v21, #v22 {
	display: none;
}
#otvet {

	margin: 30px;
	font-size: 16px;
}
.col-sm-6 {
padding-left: 20px !important;
padding-right: 20px !important;
}