html,
body {
  height: 100%;
}

.logo {
    max-width:150px;
    width:100%;
}
@media (min-width: 768px) {
    .logo {
        max-width:200px;
    }
}
     
body {
  display: flex;
  align-items: center;
  padding-top: 40px;
  padding-bottom: 40px;
  background-color: #f5f5f5;
}

.form-signin {
  width: 100%;
  max-width: 500px;
  padding: 15px;
  margin: auto;
}

.btn-purple {
  color:#FFF;
  background-color:#093c71;
  border-color:#093c71;
}
.btn-purple:hover {
  color:#FFF;
  background-color:#214f7f;
  border-color:#214f7f;
}