body {
    height: 100vh;
    background-image: url("bg.jpg");
    background-size: cover;
    font-family: 'Roboto', sans-serif;
}

.card {
    max-width: 600px;
}
.hidden {
    display: none
}

@media only screen and (max-width: 600px) {
    body {
        background-image: url("bg-mobile.jpg");
    }
  }