#canvas {
  position:relative;
  width:80vmin;
  height:80vmin;
  background-color: gray;
    margin: 0 auto
}

#col2 {
  top:0;
  left:27vmin;
  position:absolute;
  background-color: #792d0b;
  height:80vmin;
  width:27vmin;
}

#col3{
  top:0;
  left:53vmin;
  position:absolute;
  background-color: peru;
  height:80vmin;
  width:27vmin;
}