body {
  background-color: #F7F7F7;
  font-size: 16px;
}

#main {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 32em;
  height: 18em;
}

.dot {
  float: left;
  margin: .25em;
  width: .5em;
  height: .5em;
  border-radius: 50%;
}