.about_nav {
  max-width: 900px;
  margin: 0 auto;
  text-align: center;
}

.about_nav li {
  display: inline-block;
  width: 266px;
  margin-bottom: 8px;
  vertical-align: top;
}

.about_nav li .atv {
  display: none;
}

.about_nav li.nav_on .off {
  display: none;
}

.about_nav li.nav_on .atv {
  display: block;
}

.about_nav li.nav_on a {
  -webkit-animation: none !important;
          animation: none !important;
}

.about_nav li a {
  display: block;
}

@media screen and (max-width: 767px) {
  .about_nav li {
    width: 43.5%;
    margin-bottom: 6px;
  }
}