<!DOCTYPE html>
<html lang="pt-br">
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1">
<!-- The above 3 meta tags *must* come first in the head; any other head content must come *after* these tags -->
<title>Bootstrap</title>
<!-- Bootstrap -->
<link href="bootstrap/css/bootstrap.min.css" rel="stylesheet">
<!-- HTML5 shim and Respond.js for IE8 support of HTML5 elements and media queries -->
<!-- WARNING: Respond.js doesn't work if you view the page via file:// -->
<!--[if lt IE 9]>
<script src="https://oss.maxcdn.com/html5shiv/3.7.3/html5shiv.min.js"></script>
<script src="https://oss.maxcdn.com/respond/1.4.2/respond.min.js"></script>
<![endif]-->
<link href="estilo.css" rel="stylesheet">
</head>
<body>
<div class="container">
<div class="page-header">
<h1>Butões bootstrap</h1>
<div class="row">
</div>
<div class="col-sm-6">
<h3>Butões Padrão</h3>
<a href="#" class="btn btn-default">BotãoLink</a>
<input type="submit" class="btn btn-default" value="enviar" name="">
<button class="btn btn-default">Botão</button>
</div>
<div class="col-sm-6">
<h3>Tipos de Botões</h3>
<button class="btn btn-default">Botão</button>
<button class="btn btn-primary">Botão</button>
<button class="btn btn-success">Botão</button>
<button class="btn btn-danger">Botão</button>
<button class="btn btn-warning">Botão</button>
<button class="btn btn-info">Botão</button>
<button class="btn btn-link">Botão</button>
</div>
</div>
</div>
<div class="row">
<div class="col-sm-6">
<h3>Butões nivel de bloco</h3>
<button class="btn btn-default btn-block">Botão</button>
<button class="btn btn-default btn-block">Botão</button>
</div>
<div class="col-sm-6">
<h3>Butões</h3>
<button class="btn btn-default btn-block btn-xs">Botão</button>
<button class="btn btn-default btn-block btn-sm">Botão</button>
<button class="btn btn-default btn-block btn-md">Botão</button>
<button class="btn btn-default btn-block btn-lg">Botão</button>
</div>
</div>
<!-- jQuery (necessary for Bootstrap's JavaScript plugins) -->
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>
<!-- Include all compiled plugins (below), or include individual files as needed -->
<script src="bootstrap/js/bootstrap.min.js"></script>
</body>
</html>
Estou tendo um problema com esse código ao qual o alinhamento dos conteiners não se da sozinho o que posso fazer?