body {
  background: linear-gradient(135deg, #f8d7da, #d1ecf1, #fff3cd, #d4edda);
  background-size: 400% 400%;
  animation: gradient 15s ease infinite;
  font-family: 'Poppins', sans-serif;
  margin: 0;
  padding: 0;
}
@keyframes gradient {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}
.container {
  max-width: 400px;
  margin: 100px auto;
  padding: 40px;
  background: white;
  border-radius: 20px;
  box-shadow: 0 10px 30px rgba(0,0,0,0.2);
  text-align: center;
}
h1 {
  color: #dc3545;
}
.tagline {
  color: #007bff;
  font-weight: 300;
  margin-bottom: 30px;
}
input {
  width: 100%;
  padding: 12px;
  margin: 10px 0;
  border: 1px solid #ced4da;
  border-radius: 10px;
  font-size: 16px;
}
button {
  background-color: #28a745;
  color: white;
  padding: 12px 20px;
  border: none;
  border-radius: 12px;
  font-size: 16px;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.3s;
}
button:hover {
  background-color: #218838;
}
.error {
  color: #dc3545;
  font-weight: bold;
  margin-top: 10px;
}