* { margin: 0; padding: 0; box-sizing: border-box; }
html, body { height: 100%; background: #000; overflow: hidden; }
#photo {
  width: 100%;
  height: 100%;
  object-fit: contain;
  display: block;
  margin: auto;
  cursor: pointer;
  -webkit-user-select: none;
  user-select: none;
}
#caption {
  position: fixed;
  bottom: 10px;
  left: 50%;
  transform: translateX(-50%);
  color: #888;
  font-family: sans-serif;
  font-size: 14px;
  text-align: center;
  width: 100%;
}