<div class="cp_qa01">
  <div class="cp_actab">
  <input id="cp_tabfour011" type="checkbox" name="tabs">
  <label for="cp_tabfour011">質問テキスト</label>
    <div class="cp_actab-content">
    <p>答えテキスト</p>
    </div>
  </div>
  <div class="cp_actab">
  <input id="cp_tabfour012" type="checkbox" name="tabs">
  <label for="cp_tabfour012">質問テキスト</label>
    <div class="cp_actab-content">
    <p>答えテキスト</p>
    </div>
  </div>
  <div class="cp_actab">
  <input id="cp_tabfour013" type="checkbox" name="tabs">
  <label for="cp_tabfour013">質問テキスト</label>
    <div class="cp_actab-content">
    <p>答えテキスト</p>
    </div>
  </div>
</div>

.cp_qa01 {
  border-top: 1px solid #1b2538;
}
.cp_qa01 .cp_actab input {
  display: none;
}
/*質問テキスト*/
.cp_qa01 .cp_actab {
  position: relative;
  overflow: hidden;
  width: 100%;
  margin-bottom: 1px;
  color: #1b2538;
}
.cp_qa01 .cp_actab label {
  font-weight: bold;
  position: relative;
  display: flex;
  align-items: center;
  margin: 0 0 0 0;
  padding: 1em 2em 1em 1em;
  cursor: pointer;
  border-bottom: 1px solid #1b2538;
}
.cp_qa01 .cp_actab .cp_actab-content p {
  margin: 1em;
}
.cp_qa01 .cp_actab label:hover {
  color: #00838F;
}
.cp_qa01 .cp_actab input:checked ~ label {
  color: #00838F;
}
/*答えテキスト*/
.cp_qa01 .cp_actab .cp_actab-content {
  overflow: hidden;
  max-height: 0;
  color: #ffffff;
  background: rgba(0, 131, 143, 0.5);
  transition: max-height 0.5s ease;
}
.cp_qa01 .cp_actab input:checked ~ .cp_actab-content {
  max-height: 40em;
}
/*▼アイコン*/
.cp_qa01 .cp_actab label::after {
  position: absolute;
  content: '';
  right: 10px;
  width: 15px;
  height: 10px;
  background: #1b2538;
  clip-path: polygon(0 0, 50% 100%, 100% 0);
  transition: all 0.5s ease;
}
.cp_qa01 .cp_actab label:hover::after {
  background: #00838F;
}
.cp_qa01 .cp_actab input[type=checkbox]:checked + label::after {
  transform: rotateX(180deg);
  background: #00838F;
}