body.light {
  background: #fff;
  color: #000;
  font-family: sans-serif;
}
body.dark {
  background: #121212;
  color: #f9f9f9;
}
nav {
  display: flex;
  justify-content: space-between;
  padding: 1rem 2rem;
  background: rgba(255, 255, 255, 0.8);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(10px);
}
.nav-container {
  display: flex;
  align-items: center;
  gap: 2rem;
}
.nav-container ul {
  display: flex;
  list-style: none;
  gap: 1.5rem;
}
section {
  padding: 2rem;
}
footer {
  text-align: center;
  padding: 2rem;
  border-top: 1px solid #ccc;
}