.gallery {
  margin: 0 auto;
  }
  
.gallery img {
  padding: 1px;
  display:block;
  margin:0;
  }

.img-container {
  display: inline-block;
  margin: 0;
  }
  
.img-container img {
  display: block;
  }

.img-container .caption {
  width: auto;
  background: #080a0e;
  color: #eee;
  display: none;
  max-width:400px;
  padding: 3px 7px 3px 7px;
  font-size:0.875em;
  margin:1px;
  margin-left: -2px;
  margin-top: 3px;
  }

.img-container:hover {
  outline: 1px solid #79f5a8;
  }

.img-container:hover .caption, .img-container:focus-within .caption {
  display: block;
  position:absolute;
  }