body {
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 0;
  background: #f9f9f9;
  color: #222;
}
header {
  background: #222;
  color: #fff;
  padding: 1em 0;
}
nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  justify-content: center;
  gap: 2em;
}
nav ul li {
  display: inline;
}
nav a {
  color: #fff;
  text-decoration: none;
  font-weight: bold;
}
nav a:hover {
  text-decoration: underline;
}
main {
  max-width: 800px;
  margin: 2em auto;
  background: #fff;
  padding: 2em;
  border-radius: 8px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}
footer {
  background: #222;
  color: #fff;
  text-align: center;
  padding: 1em 0;
  position: fixed;
  width: 100%;
  bottom: 0;
}
footer nav a {
  color: #fff;
  margin: 0 0.5em;
  text-decoration: none;
}
footer nav a:hover {
  text-decoration: underline;
}
@media (max-width: 600px) {
  main {
    padding: 1em;
  }
  nav ul {
    flex-direction: column;
    gap: 1em;
  }
}