body {
  font-family: Arial, sans-serif;
  margin: 0;
  background: #f4f4f4;
  color: #333;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  text-align: center;
}

header, footer {
  background: #4285f4;
  color: white;
  padding: 15px;
}

main {
  flex: 1;
  padding: 20px;
}

form {
  display: flex;
  flex-direction: column;
  gap: 10px;
  max-width: 300px;
  margin: 20px auto;
}

input, button {
  padding: 10px;
  font-size: 16px;
}

button {
  background: #4285f4;
  color: white;
  border: none;
  cursor: pointer;
}

button:hover {
  background: #3367d6;
}

.dark-mode {
  background: #222;
  color: #eee;
}

.dark-mode header, .dark-mode footer {
  background: #111;
}