.read-more-state {
  display: none;
}

.read-more-target {
  opacity: 0;
  max-height: 0;
  font-size: 0;
  transition: .25s ease;
}

.read-more-state:checked ~ .read-more-wrap .read-more-target {
  opacity: 1;
  font-size: inherit;
  max-height: 999em;
}

.read-more-state ~ .read-more-trigger:before {
  content: 'Read more >>';
}

.read-more-state:checked ~ .read-more-trigger:before {
  content: 'Show less <<';
}

.read-more-trigger {
  cursor: pointer;
  display: inline-block;
  padding: 0 .5em;
  color: #666;
  font-size: .9em;
  line-height: 2;
  border: 1px solid #ddd;
  border-radius: .25em;
}

#myTopBtn {
  display: none;
  position: fixed;
  bottom: 20px;
  right: 30px;
  z-index: 99;
  font-size: 18px;
  border: none;
  outline: none;
  background-color: darkblue;
  color: white;
  cursor: pointer;
  padding: 15px;
  border-radius: 4px;
}

#myTopBtn:hover {
  background-color: #555;
}