.about .hidden_show {
  /* height: 0; */
  padding: 1em 0;
  /* overflow: hidden; */
  /* opacity: 0; */
  /* transition: 0.8s; */
}

.about input:checked~.hidden_show {
  padding: 1em 0;
  margin-bottom: -1em;
  height: auto;
  opacity: 1;
}

.about label {
  cursor: pointer;
}

.about input {
  display: none;
}

/*	pic size
============================== */
@media all and (min-width: 768px) {
  .pic3 {
    display: flex;
  }

  .ph_cut, .ph_cut span {
    width: 700px;
    height: 700px;
  }
}

@media all and (max-width: 767px) {
  .ph_cut span {
    padding-top: calc((700 / 700)*100%);
  }
}