body {
  font-family: Arial;
  margin: 0;
  padding: 0;
  text-align: center;
}

nav {
  background: #333;
  padding: 10px;
}

nav a {
  color: white;
  margin: 10px;
  text-decoration: none;
}

.slider img {
  width: 100%;
  height: 300px;
  display: none;
}

.gallery img {
  width: 200px;
  margin: 10px;
}