<img id='join' src='images/join.png'>
    <div id='buttons'>
      <div id='different'>
        <img id='red' src='images/red.png'>
        different
      </div>
      <div id='same'>
        <img id='green' src='images/green.png'>
        same
      </div>
    </div>
  </div>
</body>
#main, #different, #same {
  display:flex;
  flex-direction:column;
  align-items:center;
}
#join {
  height:8vmin;
}
#buttons {
  margin-top:3vmin;
  display:flex;
  width:50vmin;
  justify-content:space-around;
  font-size:6vmin;
}
#red, #green {
  height:12vmin;
}