<link href="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//maxcdn.bootstrapcdn.com/bootstrap/4.1.1/js/bootstrap.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
<div class="container">
<div class="row">
<div id='divlogin'>
<h3>LOGIN</h3>
<div id='divform'>
<form id='formlogin'>
<label for='em' >E-mail</label>
<input id='em' type='email' required placeholder="digite seu e-mail">
<label for='pas' >Senha</label>
<input id='pas' required type='password' placeholder='digite a senha'>
<input id="but" type='button' value='entrar'>
</form>
</div>
<a href='#' style='text-decoration:none;'>Precisa de ajuda?</a>
<p id='erro'>Senha ou E-mail incorretos</p>
</div>
</div>
<div class='row'>
<div class='col text-center'>
<footer>Me siga no instagram @augusto_brz</footer>
</div>
</div>
</div>