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<div>
  <input type="checkbox" class="read-more-state" id="post-1" />
  <p class="read-more-wrap">Lorem ipsum dolor sit amet, consectetur adipisicing elit. <span class="read-more-target">Libero fuga facilis vel consectetur quos sapiente deleniti eveniet dolores tempore eos deserunt officia quis ab? Excepturi vero tempore minus beatae voluptatem!</span></p>
  <label for="post-1" class="read-more-trigger"></label>
</div>
<div>
  <input type="checkbox" class="read-more-state" id="post-2" />
  <ul class="read-more-wrap">
    <li>lorem</li>
    <li>lorem 2</li>
    <li class="read-more-target">lorem 3</li>
    <li class="read-more-target">lorem 4</li>
  </ul>
  <label for="post-2" class="read-more-trigger"></label>
</div>
.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: 'Show 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;
}