@media (max-width: 750px) {
  .key_visual .kv_container {
    width: 100%;
  }

  .key_visual {
    background: url(../images/vc_main_visual_sp.png)
      no-repeat center / cover;
  }

  .page-menu {
    width: 100%;
  }

  .voices-box .new::before {
    border-width: 55px 55px 0 0;
  }

  .voices-box .new::after {
    transform: rotate(-45deg) translate(-20%, 40%);
  }
}