body {
  background-color: black;
}

.clock-column {
  display: inline-block;
  width: calc(100% / 7);
  margin: 0 auto;
}

.dot:before {
  content: '';
  display: block;
  padding-top: 100%;
}

.dot {
  position: relative;
  max-width: 100%;
  margin: 0.5rem;
  background-color: firebrick;
  border-color: firebrick;
  background-size: 100% auto;
  border-radius: 50%;
  border-style: solid;
  height: calc(100vh / 5);
  width: calc(100vh / 5);
}

.dot.off {
  background-color: transparent;
}