.japan_map{
position: relative;
box-sizing: border-box;
margin: 0 auto;
display: table;
background-color: transparent;
  }
  .japan_map img{
max-width: 100%;
height: auto;
border: 0;
-webkit-backface-visibility: hidden;
  }
  .japan_map .area_btn{
position: absolute;
z-index: 1;
box-sizing: border-box;
cursor: pointer;
border: 3px solid #333333;
border-radius: 5px;
background-color: #FFF;
padding: 0.2em auto;
font-weight: bold;
text-align: center;
white-space: nowrap;
  }
  
  .japan_map .area_btn.area1{
top: 30%;
right: 0;
width: 30%;
  }
  .japan_map .area_btn.area2{
top: 58%;
right: 11%;
width: 13%;
  }
  .japan_map .area_btn.area3{
top: 56%;
right: 27.5%;
width: 13%;
  }
  .japan_map .area_btn.area4{
top: 65%;
right: 44%;
width: 13%;
  }
  .japan_map .area_btn.area5{
top: 52%;
left: 20%;
width: 25%;
  }
  .japan_map .area_btn.area6{
top: 70%;
left: 0;
width: 25%;
  }
  .japan_map .area_overlay{
display: none;
position: absolute;
z-index: 2;
top: 0;
left: 0;
min-width: 100%;
min-height: 100%;
width: auto;
height: auto;
background-color: #111;
opacity: 0.5;
cursor: pointer;
  }
  .japan_map .pref_area{
display: none;
  }
  .japan_map .pref_list{
position: absolute;
top: 50%;
left: 50%;
transform: translateY(-50%) translateX(-50%);
-webkit-transform: translateY(-50%) translateX(-50%);
z-index: 3;
box-sizing: border-box;
display: -webkit-flex;
display: flex;
-webkit-flex-wrap: wrap;
flex-wrap: wrap;
width: 90%;
background-color: #FFF;
  }
  .japan_map .pref_list > div{
box-sizing: border-box;
width: 50%;
border: 1px solid #CCC;
font-weight: bold;
text-align: center;
padding: 0.5em;
cursor: pointer;
  }
  
  @media screen and (max-width: 480px){
/* スマホユーザー向けにボタン文字サイズを調整 */
.japan_map .area_btn{
font-size: 4vw;
}
  }