I need to center that form (That the form is in the center of the page) and I do not know how, I leave code:
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" crossorigin="anonymous">
<section id="cover">
<div id="cover-caption">
<div id="container" class="container">
<div class="row">
<div class="col-sm-10 offset-sm-1 text-center">
<h1 class="display-3">Bienvenidos a intranet</h1>
<div class="info-form mt-5">
<form action="" class="form-inline justify-content-center">
<div class="form-group align-self-center">
<label class="sr-only">Nombre</label>
<input type="text" class="form-control" placeholder="Usuario">
</div>
<div class="form-group">
<label class="sr-only">COntraseña</label>
<input type="text" class="form-control" placeholder="Contraseña">
</div>
<button type="submit" class="btn btn-success ">Ingresar</button>
</form>
</div>
<br>
</div>
</div>
</div>
</div>
</section>