body {
  font-family: sans-serif;
  text-align: center;
  margin: 0;
  padding: 0;
  overflow: hidden;
}

h1 {
  margin-top: 20px;
}

#dots {
  position: absolute;
  width: 100%;
  height: 100%;
  top: 0;
  left: 0;
}

.cal-dot {
  width: 20px;
  height: 20px;
  background: red;
  border-radius: 50%;
  position: absolute;
  transform: translate(-50%, -50%);
  cursor: pointer;
  z-index: 10;
}