canvas {
  margin: 10px;
  display:block;
}

pre {
  margin-left: 20px;
  margin-right: 20px;
  padding: 5px;
  background: #FFF;
  border-top: 1px solid #333;
  border-bottom: 1px solid #333;
}

div.ref-col {
  float: left;
  width: 32%;
}

.flip_gallery canvas {margin:auto}