body {
  font-family: Arial, sans-serif;
  padding: 1em;
  background: #f5f5f5;
  color: #333;
}
h1, h2 {
  text-align: center;
}
section {
  margin-bottom: 2em;
}
#galleryList button {
  margin: 5px;
  padding: 10px;
}
.fullscreen-mode {
  position: relative;
  background: black;
  height: 100vh;
  overflow: hidden;
}
#closeViewerBtn {
  position: fixed;
  top: 10px;
  right: 10px;
  background: #000;
  color: #fff;
  font-size: 2rem;
  border: none;
  border-radius: 5px;
  padding: 5px 15px;
  z-index: 1000;
  cursor: pointer;
}
#arContainer video {
  object-fit: cover;
}