style.css

html, body {
	margin: 0;
	padding: 0;
}

.container {
	margin: 2em auto;
	max-width: calc(100% - 2em);
	width: 600px;
	font-family: sans-serif;
}

.input {
	border: 1px solid #DDD;
	box-sizing: border-box;
	border-radius: 3px;
	overflow: hidden;
	display: flex;
	flex-wrap: wrap;
}

.inputField {
	width: 100%;
	padding: .5em;
	border: none;
	font-size: 1em;
}

.btn {
	height: 100%;
	padding: .5em;
	display: flex;
	justify-content: center;
	align-items: center;
	background: lightgray;
	cursor: pointer;
	flex-grow: 1;
}

.btn.active {
	background: skyblue;
}

.output {
	margin-top: 1em;
	width: 100%;
	padding: .5em;
	box-sizing: border-box;
}

.output ul {
	list-style: none;
	margin: 0;
	padding: 0;
	display: inline;
}

.output li {
	display: none;
	cursor: pointer;
}

.output ul.active {
	background: #DDD;
	padding: 0 2px;
	border-radius: 3px;
}

.output ul.active li {
	display: inline;
	padding: 0 2px;
}

.output li.active {
	display: inline;
	color: tomato;
}

.placeholder {
	color: gray;
	font-weight: lighter;
}