body {
  font-family: 'Segoe UI', sans-serif;
  background: #f8f9fa;
  margin: 0;
  padding: 2em;
}
.container {
  max-width: 600px;
  margin: auto;
  background: white;
  padding: 2em;
  border-radius: 10px;
  box-shadow: 0 8px 24px rgba(0,0,0,0.1);
}
input, button {
  width: 100%;
  padding: 0.75em;
  margin-top: 1em;
  font-size: 1em;
}
button {
  background: #10a37f;
  color: white;
  border: none;
  cursor: pointer;
}
button:hover {
  background: #0e8c6b;
}
.hidden {
  display: none;
}
h1, h2 {
  color: #333;
}