.loader {
  text-align: center;
  position: relative;
  display: flex;
}

.loader .ball {
  box-shadow: 0 5px 10px rgba(0, 0, 0, 0.5);
}

.ball {
  display: block;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: radial-gradient(circle at 8px 5px, white 5%, black);
  position: relative;
  transform-origin: 50% -100px;
}

.ball:last-child {
  animation: balance-right 1.2s infinite linear;
}

.ball:first-child {
  animation: balance-left 1.2s infinite linear;
}

@keyframes balance-right {
  0% {
    transform: rotate(0deg);
    animation-timing-function: linear;
  }

  50% {
    transform: rotate(0deg);
    animation-timing-function: ease-out;
  }

  75% {
    transform: rotate(-30deg);
    animation-timing-function: ease-in;
  }
}

@keyframes balance-left {
  0% {
    transform: rotate(0deg);
    animation-timing-function: ease-out;
  }

  25% {
    transform: rotate(30deg);
    animation-timing-function: ease-in;
  }

  50% {
    transform: rotate(0deg);
    animation-timing-function: linear;
  }
}