style.css

.lab-title {
	width:100%;
	padding-top: 20px;
	padding-bottom: 10px;
	font-size: 30px;
	text-align: center;
	font-weight: bold;
	background-color: #339966;
	color: white;

}

.spoiler {
	margin-top: 20px;
}

.spoiler > input + label:after {
	content: "+";
	float: right;
	font-family: monospace;
	font-weight: bold;
}

.spoiler > input:checked + label:after {
	content: "-";
	float: right;
	font-family: monospace;
	font-weight: bold;
}

.spoiler > input {
	display:none;
}

.spoiler > input + label , .spoiler > .spoiler_body {
	background:#CCC;
	padding:5px 15px;
	overflow:hidden;
	width:100%;
	box-sizing: border-box;
	display: block;
}

.spoiler > input + label + .spoiler_body {
	display:none;
}

.spoiler > input:checked + label + .spoiler_body {
	display: block;
}

.spoiler > .spoiler_body {
	background: #FFF;
	border: 3px solid #CCC;
	border-top: none;
}