body {
  --ball-dia: 100px;
  -webkit-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  user-select: none;
}

h1 {
  position: absolute;
  left: 50%;
  top: 50%;
  text-align: center;
  font-size: 1rem;
  transform: translateX(-50%) translateY(-50%);
}

.ball {
  width: var(--ball-dia);
  height: var(--ball-dia);
  border-radius: 50%;
  position: absolute;
  background-color: red;
  animation: big ease 0.1s;
  mix-blend-mode: multiply;
}

.ball--first {
  left: calc(50vw - var(--ball-dia) * 0.5);
  top: calc(50vh - var(--ball-dia) * 0.5);
}

@keyframes big {
  from {
    transform: scale(0.5);
  }

  to {
    transform: scale(1);
  }
}

@-webkit-keyframes name {
  from {
    -webkit-transform: scale(0.5);
  }

  to {
    -webkit-transform: scale(1);
  }
}