div {
  display: flex;
  justify-content: center;
  align-items: center;
}

.balls {
  width: 100vw;
  height: 100vh;
}

.ball {
  width: 30vh;
  height: 30vh;
  border-radius: 50%;
  margin: 5vh;
}

.b1 {
  background-color: red;
  font-size: 100px;
}

.b2 {
  font-size: 100px;
}

.b3 {
  font-size: 100px;
}

.timer {
  background-color: black;
  color: red;
  font-size: 100px;
}