body {
  font-family: sans-serif;
  display: flex;
  height: 100vh;
  justify-content: center;
  align-items: center;
  background: #f4f4f4;
}
main {
  background: white;
  padding: 2rem;
  border-radius: 8px;
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
}
input, button {
  display: block;
  width: 100%;
  margin-bottom: 1rem;
  padding: 0.75rem;
  font-size: 1rem;
}
button {
  background: #222;
  color: white;
  border: none;
}
#error-message {
  color: red;
  font-size: 0.9rem;
}