.card {
  max-width: 500px;
  margin: 40px auto;
  background: #fff;
  padding: 25px;
  border-radius: 12px;
}

label {
  display: block;
  margin: 6px 0;
}

button {
  margin-top: 15px;
  padding: 10px 15px;
}

.mensaje-final {
  margin-top: 20px;
  padding: 15px;
  background: #e8f5e9;
  border-radius: 8px;
  display: none;
}

/* Loader */
.loader {
  width: 50px;
  height: 50px;
  border: 6px solid #e0e0e0;
  border-top: 6px solid #4caf50;
  border-radius: 50%;
  animation: girar 1s linear infinite;
  margin: auto;
}

@keyframes girar {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}