body {
  font-family: sans-serif;
  background: #f2f2f2;
  margin: 0;
  padding: 0;
}
.container {
  max-width: 500px;
  margin: 2em auto;
  padding: 2em;
  background: white;
  border-radius: 10px;
  box-shadow: 0 0 10px rgba(0,0,0,0.1);
}
input, button {
  width: 100%;
  padding: 1em;
  margin: 0.5em 0;
  font-size: 1em;
}
button {
  background-color: #007bff;
  color: white;
  border: none;
}