.galeria {
  height: calc( var(--h) + 5em);
  width: var(--w);
  margin:1em auto;
  border: 3px solid #D8A124;
  position: relative;  
}

.galeria img {
  position: absolute;
  top: 0;
  left: 0;
  opacity: 0;
  transition: opacity 2s;
}

.galeria input:checked{
  width: 20px;
  height:20px;
  background-color: blue;
}

.galeria input {
  width: 15px;
  height:15px;
  background-color: blue;
}

.galeria input:hover {
  width: 20px;
  height:20px;
  background-color: blue;
}

.galeria input[type=checkbox] {
  position: relative;
  bottom: calc(-1 * var(--h) - 1.5em);
  left: .5em;
}

.galeria input[type=checkbox]:nth-of-type(1):checked ~ img:nth-of-type(1) {
  opacity: 1;
}

.galeria input[type=checkbox]:nth-of-type(2):checked ~ img:nth-of-type(2) {
  opacity: 1;
}

.galeria input[type=checkbox]:nth-of-type(3):checked ~ img:nth-of-type(3) {
  opacity: 1;
}

.galeria input[type=checkbox]:nth-of-type(4):checked ~ img:nth-of-type(4) {
  opacity: 1;
}

.galeria input[type=checkbox]:nth-of-type(5):checked ~ img:nth-of-type(5) {
  opacity: 1;
}