html {
  height:100%;
}
body {
  margin        : 0 auto;
  min-height    : 100vh;
  font-size     : xx-large;
  display       : flex;
  flex-direction: column;
  /*overflow      : hidden;
  */
}
.content {
  position : relative;
  flex     : 1;
  max-width: 400px;
  margin: 0 auto;
}
.button {
  position  : relative;
  bottom    : -570px;
  left      : -140px;
  cursor    : pointer;
  width     : 150px;
  height    : 250px;
  z-index   : 100;
  background: none;
  border    : none;
 }
.image {
  position: relative;
  bottom  : 330px;
  right   : 190px;
  z-index : -1;
  width   : 180%;
  height: auto;
}
.image2 {
  position: relative;
  bottom  : 385px;
  width   : 50%;
  height  : 50%;
  right   : 160px;
}
.explanation {
  position: relative;
  bottom  : 550px;
  left    : 35px;
  z-index : 100;
}
 #first_words,
 #second_words,
 #last_words {
  writing-mode    : vertical-rl;
  text-orientation: upright;
  position        : absolute;
  top             : 45px;
 }
#first_words {
  left: 60%;
}
#second_words {
  left: calc(50% - 100px);
}
#last_words {
  left: calc(40% - 200px);
}