.ac-ttl{
  margin-bottom: 0;
  position: relative;
  cursor: pointer;
}
.ac-ttl::after{
  content: "";
  position: absolute;
  right: 25px;
  top: 50%;
  -webkit-transform: translateY(-50%) rotate(135deg);
  transform: translateY(-50%) rotate(135deg);
  -webkit-transition: all 0.2s ease;
  transition: all 0.2s ease;
  display: block;
  width: 10px;
  height: 10px;
  border-top: solid 2px #0f0f0f;
  border-right: solid 2px #0f0f0f;
}
.ac-ttl.open::after{
  -webkit-transform: translateY(-50%) rotate(-45deg);
  transform: translateY(-50%) rotate(-45deg);
}
.ac-cnt{
  padding-top: clamp(20.7568px,2.16216vw,24px);
  display: none;
}
.ac-ttl.open+.ac-cnt{
  display: block;
}
.ac-cnt *:first-child{
  margin-top: 0!important;
}

@media only screen and (max-width: 959px) {
  /* SP用 */
  .ac-ttl::after{
    width: 2.5vw;
    height: 2.5vw;
    border-top: solid .55vw #0f0f0f;
    border-right: solid .55vw #0f0f0f;
  }
  .ac-cnt{
    padding-top: clamp(0px,4.103vw,20.5128px);
  }
}

@media only screen and (min-width: 960px) {
  /* PC用 */
}

@media (prefers-color-scheme: dark) {
  .ac-ttl::after{
    border-color: #fff;
  }
}