Untitled

<!DOCTYPE html>
<html>
<head>
	<title></title>
	<style type="text/css">
		.container{
			border: 1px solid #999;
		}
		label{
			display: block;
		}
	</style>
</head>
<body>

<div class="container">
	<label>username:</label><input type="text" name="">
	<label>pass: <input type="password" name=""></label>
</div>
<button class="btn">Click</button>
<div class="output"></div>


<script type="text/javascript">
let container = document.querySelector('.container');

function clickInputHandler(e){
	let el = e.target;

	console.log(el.tagName);

	if (el.tagName == "INPUT"){
		el.style.background = "red";
	}
}

container.addEventListener('click', clickInputHandler )

</script>
</body>
</html>