body.app {
  font-family: sans-serif;
  margin: 0;
  background: #f5f5f5;
}
.app-bar {
  background: #121212;
  color: #fff;
  padding: 1em;
}
.card {
  background: #fff;
  margin: 1em;
  padding: 1em;
  border-radius: 8px;
}
.error { color: red; }