combobox.css

.combobox {
	position:relative;
	display:inline-block;
	box-sizing: border-box;
	margin:0px;
	padding:0px;
	width:100%;
}

.combobox > .open-button {
	box-sizing: border-box;
	position:absolute;
	display:inline-block;
	vertical-align:text-bottom;
	right:0px;
	top: 0px;
	bottom:0px;
	padding: 4px 8px;
	color: #999;
	cursor: pointer;
	background-color:#eee;
	border: solid 1px #ddd;
	border-top-right-radius: 4px;
	border-bottom-right-radius: 4px;
}

.combobox > input {
	box-sizing: border-box;
	border:solid 1px #ddd;
	border-radius: 4px;
	padding:8px 12px;
	margin:0px;
	width:100%;
}

.combobox > [role="menu"] {
	position:absolute;
	z-index:10;
	left:0px;
	right:0px;
	border: solid 1px #ddd;
	border-radius: 4px;
	background-color: #f8f8f8;	
	box-shadow: 0px 2px 2px 2px rgba(0,0,0,0.1);
	max-height: 300px;
	overflow-y: scroll;
}

.combobox [role="menuitem"] {
	padding: 8px 8px;
	cursor: pointer;
}

.combobox [role="menuitem"].selected {
	background-color:cornflowerblue;
	color:white;
}

.selected .gray50 {
	color:white;
}