/* Just some minimal styling for demo purposes */
.imgbox {
  position: relative;
  width: 859px;
  height: 245px;

}

.imgbox img {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

/* Make sure the second image isn't visible at first */
#img2 {
  opacity: 0;
  transition: opacity .5s;
}