body {
  color: #24292f;
  font-family: -apple-system,BlinkMacSystemFont,Segoe UI,Helvetica,Arial,sans-serif;
  font-size: 14px;
}

#flip-book {
  border: 1px solid #ccc;
  box-shadow: 2px 4px 4px #666;
  margin: 10% auto 0 auto;
}

#flip-book:hover .page {
  transition: transform 100ms ease-in;
}