.jp {
 font-family: 'Noto Sans JP', sans-serif;
}
.en {
   font-family: 'Roboto', sans-serif;
}
.button {
  border: Noto Sans JP;
  border-radius: 5px;
  background-color: #00FF80;
  padding: 20px;
  text-align: center;
  color: #000000;
  width: 150px;
}
.Up {
  position: -webkit-sticky;
  position: sticky;
  top: 0;
}
.back {
  background-color: #66FFB2;
  padding: 30px;
}