silverstripe-framework/css/TreeDropdownField.css

div.TreeDropdownField {
	width: 200px;
	height: 21px;
}

div.TreeDropdownField .title {
	float: left;
	overflow:hidden;
	width: 174px;
	height: 14px;
	border: 1px #7f9db9 solid;
	cursor: pointer;
	padding: 2px 0 2px 4px;
	background-color: #fff;
}

div.TreeDropdownField .panel {
	position:relative;
	overflow: auto;
	display: none;
	z-index: 1000;
	cursor: default;
	border: 1px black solid;
	width: 200px;
	height: 200px;
	background-color: #fff;
}

div.TreeDropdownField .panel.loading {
	background: #fff url(../images/network-save.gif) center center no-repeat;
}

div.TreeDropdownField .panel ul.tree a {
	font-size: 12px;
}

div.TreeDropdownField .panel ul.tree {
	margin-top: 0;
}

div.TreeDropdownField .toggle-panel-link {
	border:none;
	text-decoration: none;
	background: url(../images/TreeDropdownField_button.gif) no-repeat left top;
	width: 19px;
	height: 21px;
	margin: 0;
	padding: 0 0 0 1px;
	z-index: 0;
	overflow: hidden;
	float:right;
}

div.TreeDropdownField .jstree-themeroller a.jstree-loading .jstree-icon { 
	background:url("../images/network-save.gif") center center no-repeat !important; 
}