.clock {
  width: 200px;
  height: 200px;
  border: 5px solid black;
  border-radius: 50%;
  position: relative;
}

/* MARKERS */
.mark {
  position: absolute;
  top: 0;
  left: 50%;
  transform-origin: center 100px;
  background: black;
}

/* Minute ticks */
.mark {
  width: 1px;
  height: 6px;
  opacity: 0.6;
}

/* Hour ticks (every 5th) */
.mark.hour-mark {
  height: 12px;
  width: 2px;
  opacity: 1;
}

.hand {
  position: absolute;
  bottom: 50%;
  left: 50%;
  transform-origin: bottom center;
}

.hour { height: 50px; width: 4px; background: black; }
.minute { height: 70px; width: 3px; background: black; }
.second { height: 90px; width: 2px; background: red; }

.hour, .minute {
  transform-origin: bottom center;
  will-change: transform;
}