body {
  background: #0e1116;
  color: #e8edf5;
}

main {
  width: 100%;
  max-width: 500px;
  background: #151a23;
  border: 1px solid #1e2634;
  border-radius: 14px;
  padding: 1.5rem;
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.35);
}

#sequence {
  font-family: 'Roboto Mono', monospace;
  font-size: 1.8rem;
  text-align: center;
  padding: 1rem;
  border: 1px dashed #27334c;
  border-radius: 10px;
  user-select: none;
  margin: 1rem 0;
}

#feedback.good { color: #16a34a; }
#feedback.bad { color: #dc2626; }

a.button.back {
  background: #263247;
  text-decoration: none;
}