#start_page {
  margin: 0;
  position: fixed;
  display: flex;
  justify-content: center;
  align-items: center;
  width: 100%;
  height: 100%;
  z-index: 10000000;
}

#start_page_img {
  max-width: 100%;
  max-height: 100%;
  width: auto;
  height: auto;
}