body{
    background-size: 100vw 100vh;
    width:100%;max-width:100%;
    text-align:center; /*ページ全体を中央揃えにする*/
    position: relative;
    background-color:#e3ebf3;
    overflow-x: hidden;
    font-size: 20px;
    font-family: "Hiragino Mincho ProN", "ヒラギノ明朝 ProN", "Hiragino Mincho Pro", "ヒラギノ明朝 Pro", serif;
    font-size: 25px;
    height: 100vh;
    margin: 0;
}
h2{
  border-bottom: solid 3px #364e96;
  border-width: 0px 0px 3px 0px;
  border-style: dotted;
  margin: 3rem 15%;
}
h3{
  text-align: left;
  border-left: 1rem solid #364e96;
  border-bottom: 1px solid #364e96;
  margin: 3rem 15%;
  padding: 0px 2rem;
}
p{
  margin: 1rem 20%;
  text-align: left;
  line-height: 2.5rem;
}
  /* .back{
    background-image: url(we_can_sea.png);
    background-repeat: no-repeat;
    background-size: cover;
    background-position: center top;
    height: 100vh;
    /* padding-top: 500px; 
  } */
mark{
  background: linear-gradient(transparent 40%, #00bbffb7 80%);
}

  .part {
    
    opacity: 0;
    transform: translateY(100%);
    animation: slideInFromBottom 1s forwards;
    animation-timing-function: ease;
  }
  
  @keyframes slideInFromBottom {

    from {
      opacity: 0;
      transform: translateY(100px);
    }

    to {
      opacity: 1;
      transform: translateY(0px);
    }
  }

.parts{
  opacity: 0;
}

.top_dis{
  width: 100%;
  height: 100vh;
  background-image: url(../top_pic/sea_imp.webp);
  background-repeat: no-repeat;
  background-size: cover;
  background-position: center top;
  position: relative;
}
.back{
  position: absolute;
  top: 85%; left: 50%;
  transform: translate(-50%,-50%);
  text-align: center;
}
.syakai{
  width: 50%;
}
.content{
  margin-bottom: 30px;
}
a{
  text-decoration: none;
}
.item-none{
  display: none;
}

@media screen and (max-width: 1300px){
  /*パソコン（小）*/
  body{
      font-size: 20px;
  }
  .back_text{
      font-size: 55px;
  }
  .big_title{
      width: 60%;
      font-size: 22px;
  }
}
@media screen and (max-width: 600px){
  body{
    font-size: 14px;
  }
}