.gallery-nav ul {
  list-style: none;
  padding: 0;
  margin: 0 0 20px 0;
  display: flex;
  gap: 10px;
}

.gallery-nav a {
  display: block;
  padding: 10px 15px;
  background: #eee;
  border-radius: 5px;
  text-decoration: none;
  color: #333;
}

.gallery-nav a.active {
  background: #333;
  color: #fff;
}

.gallery {
  display: none;
}

.gallery.active {
  display: block;
}

.image-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 10px;
}

.image-grid a {
    background-size: cover;
    background-position: center;
    width: 200px;
    height: 200px;
}
.image-grid img {
    width: 100%;
    height: 100%;
    -o-object-fit: cover;
       object-fit: cover;
}