#kv.top {
  background: url("../img/challenge_login.jpg");
  background-size: cover;
  background-position: 100% 24%;
}
#kv.mypage-top {
  background: url("../img/challenge_mypage.jpg");
  background-size: cover;
  background-position: 100% 15%;
}
._author {
  position: absolute;
  bottom: 10px;
  color: #b1b1b1;
  right: 18px;
  font-size: 14px;
}