.gallery {
  visibility: hidden;
  position: fixed;
  top: 0px;
  left: -100%;
  height: 100%;
  width: 100%;
  background-color: #333;
  overflow-y: auto;
  overflow-x: hidden;
  text-align: center;
  opacity: 0;
  margin: 0;
  padding: 0;
  transition: opacity 0.25s ease-in, left 0.25s ease-in;
}
.gallery_visible {
    opacity: 1;
    left: 0;
    transition: opacity 0.25s ease-in, left 0.25s ease-in;
}
.gallery .header {
  width: 100%;
  text-align: left;
  background-color: black;
  padding: 12px;
  border-bottom: 2px solid #999;
}
.gallery .header a {
  text-decoration: none;
  color: white;
  font-size: 1.2em;
  font-weight: bold;
}
.gallery a {
  color: white;
}
.gallery img {
  padding-bottom: 50px;
  padding-top: 50px;
  border-bottom: 1px dotted #999;
  max-width: 90%;
}