body {
  font-family: sans-serif;
  background: #f0f4ff;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
}
.container {
  background: white;
  padding: 2rem;
  border-radius: 12px;
  text-align: center;
  box-shadow: 0 4px 16px rgba(0,0,0,0.1);
}
input, button {
  padding: 0.7rem;
  margin: 0.5rem;
  width: 80%;
  border: 1px solid #ccc;
  border-radius: 8px;
}
button {
  background: #3b82f6;
  color: white;
  border: none;
  cursor: pointer;
}
.success { color: green; }
.error { color: red; }