Untitled

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Mi sitio web</title>
    <link rel="stylesheet" href="css/bootstrap.min.css">
    <link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.8.2/css/all.css" integrity="sha384-oS3vJWv+0UjzBfQzYUhtDYW+Pj2yciDJxpsK1OYPAYjqT085Qq/1cq5FLXAZQ7Ay" crossorigin="anonymous">
    <link rel="stylesheet" href="css/custom.css">
</head>
<body>
	<header class="row alto-100px bg-color-verde">
		<div class="container">
			Lorem Ipsum
		</div>
	</header>
	<div class="container">
		<div class="row">
			<div class="col-md-9">
				Nivel 1 .col-md-9
				<div class="row">
					<div class="col-8 col-sm-6">Nivel 2 .col-8 col-sm-6</div>
					<div class="col-4 col-sm-6">Nivel 2 .col-8 col-sm-6</div>
				</div>
			</div>
		</div>
		<!-- espaciado entre las columnas -->
		<div class="row">
			<div class="col-md-4">
				col-md-4
			</div>
			<div class="col-md-4 offset-md-4 bg-color-gris">
				col-md-4 offset-md-4
			</div>
		</div>
		<div class="row">
			<div class="col-md-3">
				col-md-3
			</div>
			<div class="col-md-3 offset-md-3 bg-color-a">
				col-md-3 offset-md-3
			</div>
		</div>
		<div class="row">
			<div class="col-md-6 offset-md-3 bg-color-b">
				col-md-6 offset-md-3
			</div>
		</div>
	</div>
    <script src="js/jquery.js"></script>
    <script src="js/bootstrap.min.js"></script>
</body>
</html>