html, body {

  height: 100%;

}

body {

  display: flex;
  background-color: #fafaf7;
}

.mypage {

  flex-grow: 1;

}

.logo_holder {

  height: 600px;
  width: 600px;
  background-image: url("../images/addroid_logo_flat.png");
  background-repeat: no-repeat;
  background-position: center center;
  background-size: cover;
  background-size: 50%;
}