body::before {
  content: "";
  display: block;
  position: fixed;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  background: url("../img/bg1.jpg") no-repeat center center/cover;
}

#content .box {
  width: 800px;
  aspect-ratio: 800/500;
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
  -webkit-box-pack: center;
  -ms-flex-pack: center;
  justify-content: center;
  -webkit-box-align: center;
  -ms-flex-align: center;
  align-items: center;
}
#content .box_inr {
  text-align: left;
  padding-right: 170px;
  position: relative;
}
#content .box_inr > * {
  position: relative;
}
#content .box_inr::before {
  content: "";
  position: absolute;
  right: -20px;
  bottom: -10px;
  width: 210px;
  aspect-ratio: 420/326;
  background: url("../img/about_stamp.png") no-repeat 0 0/contain;
}
#content h3 {
  font-size: 1.4rem;
  font-weight: 700;
  letter-spacing: 0.02em;
}
#content h3 .en {
  font-family: "nimbus-sans", sans-serif;
  font-size: 2.3rem;
  padding-right: 0.4em;
}
#content .txt {
  margin-top: 30px;
  font-weight: 600;
  font-size: 1.4rem;
  line-height: 1.75;
}
#content .txt p + p {
  margin-top: 1em;
}
#content .since {
  margin-top: 25px;
  font-family: "nimbus-sans", sans-serif;
  font-weight: 700;
  letter-spacing: 0.02em;
}