.gallery {
  display: flex;
  flex-wrap: wrap;
}

.thumbnails {
  flex: 1;
  display: flex;
  flex-wrap: wrap;
}

.thumbnail {
  width: 100px;
  height: 100px;
  margin: 5px;
  cursor: pointer;
}

.lightbox {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.8);
  justify-content: center;
  align-items: center;
}

.lightbox-img {
  max-width: 100%;
  max-height: 100%;
}

.close-btn {
  position: absolute;
  top: 15px;
  right: 15px;
  font-size: 30px;
  color: #fff;
  cursor: pointer;
}