body {
  font-family: Arial, sans-serif;
  background: #f4f6f9;
  padding: 50px 0;
}

.container {
  background: #fff;
  padding: 30px;
  max-width: 480px;
  margin: auto;
  text-align: center;
  border-radius: 12px;
}

input, button {
  width: 100%;
  padding: 12px;
  margin: 12px 0;
}

button {
  background: #4f7cf3;
  color: #fff;
  border: none;
  cursor: pointer;
}

.error {
  color: red;
}

.modal {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.6);
  justify-content: center;
  align-items: center;
}

.modal-content {
  background: #fff;
  padding: 25px;
  border-radius: 10px;
}