.gnavi__item{
  position: relative;
}

.mega-menu{
  position: absolute;
  top: calc(100% + 40px);
  left: -50%;
  z-index: 100;
  opacity: 0;
  pointer-events: none;
  -webkit-transition: opacity .2s ease .2s;
  -o-transition: opacity .2s ease .2s;
  transition: opacity .2s ease .2s;
}

.mega-menu.show{
  pointer-events: auto;
}

.mega-menu .mega{
  display: -ms-grid;
  display: grid;
  grid-template-rows: repeat(4,1fr);
  grid-template-columns: repeat(3,1fr);
  grid-auto-flow: column;
  gap: 1em 1em;
  width: 500px;
  padding: 20px 30px;
  background-color: #FFF;
  -webkit-box-shadow: 0 0 20px rgba(0,0,0,.1);
          box-shadow: 0 0 20px rgba(0,0,0,.1);
  border-radius: 20px;
}

.mega__item a{
  display: block;
  width: 100%;
  height: 100%;
  color: #2f3093;
  font-weight: 500;
  line-height: 2;
  position: relative;
  text-align: center;
}

.mega__item a span{
  display: block;
}

.mega__item a span::after{
  content: "";
  display: block;
  width: 4em;
  height: 2px;
  position: absolute;
  bottom: -5px;
  left: 50%;
  background-color: #f46515;
  -webkit-transform: translateX(-50%) scaleX(0);
      -ms-transform: translateX(-50%) scaleX(0);
          transform: translateX(-50%) scaleX(0);
  -webkit-transition: -webkit-transform .2s ease;
  transition: -webkit-transform .2s ease;
  -o-transition: transform .2s ease;
  transition: transform .2s ease;
  transition: transform .2s ease, -webkit-transform .2s ease;
}
.mega__item a span.three::after{
  width: 5em;
}

.mega__item.active a span::after{
  -webkit-transform:translateX(-50%) scaleX(.6);
      -ms-transform:translateX(-50%) scaleX(.6);
          transform:translateX(-50%) scaleX(.6);
}



@media only screen and (min-width: 768px){
  .gnavi__item:first-child:hover::before{
    content: "";
    display: block;
    width: 100%;
    height: 70px;
    position: absolute;
    top: 0;
    left: 0;
  }

	.gnavi__item:first-child:hover .mega-menu{
    opacity: 1;
  }

  .mega__item a:hover span::after{
    -webkit-transform:translateX(-50%) scaleX(1);
        -ms-transform:translateX(-50%) scaleX(1);
            transform:translateX(-50%) scaleX(1);
  }

  .detail-exhibition{
    display: none !important;
  }
}




@media only screen and (max-width: 767px){
	.mega-menu{
    position: relative;
  top: 0;
  left: 0;
  z-index: initial;
  opacity:1;
  pointer-events: auto;
  -webkit-transition: height 0.4s ease-out;
  -o-transition: height 0.4s ease-out;
  transition: height 0.4s ease-out;
  height: 0;
  overflow: hidden;
  }

  .mega-menu .mega{
    grid-template-rows: repeat(6,1fr);
    grid-template-columns: repeat(2,1fr);
    gap: 1em 1em;
    width: auto;
    padding: 20px 30px;
    -webkit-box-shadow: none;
            box-shadow: none;
    border-radius: 10px;
    margin-top: 20px;
  }

  .mega__item a{
    padding-left: 0;
    text-align: center;
  }

  .detail-exhibition{
    position: absolute;
    width: 29px;
    height: 29px;
    top: 24px;
    right: 0;
  }

  .detail-exhibition::before,.detail-exhibition::after{
    content: "";
    display: block;
    width: 60%;
    height: 2px;
    border-radius: 1px;
    background-color: #FFF;
    position: absolute;
    top: 50%;
    left: 50%;
    -webkit-transition: -webkit-transform .2s ease;
    transition: -webkit-transform .2s ease;
    -o-transition: transform .2s ease;
    transition: transform .2s ease;
    transition: transform .2s ease, -webkit-transform .2s ease;
  }

  .detail-exhibition::before{
    -webkit-transform: translate(-50%,-50%);
        -ms-transform: translate(-50%,-50%);
            transform: translate(-50%,-50%);
  }
  .detail-exhibition::after{
    -webkit-transform: translate(-50%,-50%) rotate(-90deg);
        -ms-transform: translate(-50%,-50%) rotate(-90deg);
            transform: translate(-50%,-50%) rotate(-90deg);
  }

  .detail-exhibition.open::before{
    -webkit-transform: translate(-50%,-50%) rotate(180deg);
        -ms-transform: translate(-50%,-50%) rotate(180deg);
            transform: translate(-50%,-50%) rotate(180deg);
  }
  .detail-exhibition.open::after{
    -webkit-transform: translate(-50%,-50%) rotate(0);
        -ms-transform: translate(-50%,-50%) rotate(0);
            transform: translate(-50%,-50%) rotate(0);
  }
}