style.css

.collapsible-list {
	font-family: Verdana, Arial, Helvetica, sans-serif;
	font-size: 1em;
}
.collapsible-list, .collapsible-list ul {
	list-style: none outside none;
	margin: 0;
	padding: 4px 0;
}
.collapsible-list li {
	margin: 10px;
	padding-left: 24px;
}
.collapsible-list li.parent {
	text-indent: -22px;
}
.collapsible-list li.parent:before {
	content: url(images/icons/toggle-expand.png);
}
.collapsible-list li.parent.expand:before {
	content: url(images/icons/toggle-collaps.png);
}
.collapsible-list li.parent ul {
	display: none;
}
.collapsible-list li.parent.expand ul {
	display: block;
}
.collapsible-list label {
	cursor: pointer;
	color: #00f;
}
.collapsible-list input {
	display: none;
}
.collapsible-list ul.child li {
	text-indent: -20px;
}
.collapsible-list ul.child li:before {
	content: "•";
	padding-right: 12px;
	color: #00f;
}
.collapsible-list ul.child li.github:before {
	content: url(images/icons/github.png);
}
.collapsible-list ul.child li.codepen:before {
	content: url(images/icons/codepen.png);
}
.collapsible-list ul.child li.stackoverflow:before {
	content: url(images/icons/stackoverflow.png);
}
.collapsible-list ul.child li.twitter:before {
	content: url(images/icons/twitter.png);
}