body {
  margin: 0;
  font-family: Arial, sans-serif;
  background: #f4f4f4;
}

.container {
  max-width: 900px;
  margin: 50px auto;
  background: white;
  padding: 20px;
  border-radius: 8px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

h2 {
  text-align: center;
  color: #333;
}

form {
  display: flex;
  flex-direction: column;
}

input, select, label, button, textarea{
  margin: 10px 0;
  padding: 10px;
  font-size: 1rem;
}

#btn-registrar:disabled {
  background-color: #ccc;      /* Color plomo */
  color: #666;                 /* Texto más tenue */
  cursor: not-allowed;
  border: 1px solid #999;
}

button:enabled {
  background-color: #007BFF;
  color: white;
  border: none;
  border-radius: 4px;
  cursor: pointer;
}

button:hover {
  background-color: #0056b3;
}

@media (max-width: 900px) {
  .container {
    margin: 20px;
    padding: 15px;
  }

  input, button {
    font-size: 0.9rem;
  }
}

.error { color: #c00; margin-bottom: 10px; }