body {
  font-family: sans-serif;
  margin: 0;
  padding: 0;
  background-color: white;
  color: black;
}
body.dark-mode {
  background-color: #121212;
  color: white;
}
.top-bar {
  background: #444;
  color: white;
  display: flex;
  justify-content: space-between;
  padding: 1rem;
}
.logo {
  font-size: 1.5rem;
  font-weight: bold;
  color: #fff;
  text-decoration: none;
}
nav ul {
  list-style: none;
  display: flex;
  gap: 1rem;
}
nav a {
  color: white;
  text-decoration: none;
}
.hero {
  padding: 4rem;
  text-align: center;
}
.btn {
  background-color: #0084ff;
  color: white;
  padding: 0.5rem 1rem;
  text-decoration: none;
}
footer {
  text-align: center;
  padding: 1rem;
  background-color: #eee;
}