body {
  font-family: Arial, sans-serif;
  background: #f9f9f9;
  margin: 0;
  padding: 0;
}

header {
  background: #222;
  color: #fff;
  padding: 20px;
  text-align: center;
}

nav ul {
  list-style: none;
  padding: 0;
}

nav li {
  display: inline-block;
  margin: 0 10px;
}

nav a {
  color: #fff;
  text-decoration: none;
}

.gallery {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
  gap: 15px;
  padding: 20px;
}

.gallery img, .gallery video {
  width: 100%;
  border-radius: 5px;
  object-fit: cover;
}