body {
  font-family: Arial, sans-serif;
  margin: 0;
  background: #f4f4f4;
  text-align: center;
}

header {
  background: #333;
  color: white;
  padding: 20px;
}

.gallery {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 15px;
  padding: 20px;
}

.gallery img {
  width: 100%;
  border-radius: 8px;
  cursor: pointer;
}

footer {
  padding: 15px;
  color: #555;
}