timer {
  background: black;
  color: white;
  width: 120px;
  height: 120px;
  font-weight: bold;
  font-family: monospace;
  font-size: 30px;
  line-height: 60px;
  border-radius: 15px;
  text-align: center;
  margin: 20px;
  position: fixed;
  bottom: 10px;
  left: 50%;
  margin-left: -60px;
  display: none;
}

body.notes timer {
  display: block;
}