body{
	padding-top:50px;
}

.principal {
	padding: 40px; 15px;
	text-align:center;
}

.mensagem {
	text-align:center;
}

.alert-alt {
    border: 1px solid rgba(0, 0, 0, 0);
    border-radius: 4px;
    margin-bottom: 20px;
}