.pinwheel {
  --uib-size: 75px;
  --uib-speed: 1s;
  --uib-color: black;
  --uib-line-weight: 3.5px;

  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  height: var(--uib-size);
  width: var(--uib-size);
}

.pinwheel__line {
  position: absolute;
  top: calc(50% - var(--uib-line-weight) / 2);
  left: 0;
  height: var(--uib-line-weight);
  width: 100%;
  border-radius: calc(var(--uib-line-weight) / 2);
  background-color: var(--uib-color);
  animation: rotate var(--uib-speed) ease-in-out infinite;
}

.pinwheel__line:nth-child(2) {
  animation-delay: calc(var(--uib-speed) * 0.075);
  opacity: 1.0;
}

.pinwheel__line:nth-child(3) {
  animation-delay: calc(var(--uib-speed) * 0.15);
  opacity: 0.9;
}

.pinwheel__line:nth-child(4) {
  animation-delay: calc(var(--uib-speed) * 0.225);
  opacity: 0.8;
}

.pinwheel__line:nth-child(5) {
  animation-delay: calc(var(--uib-speed) * 0.3);
  opacity: 0.6;
}

.pinwheel__line:nth-child(6) {
  animation-delay: calc(var(--uib-speed) * 0.375);
  opacity: 0.5;
}
.pinwheel__line:nth-child(7) {
  animation-delay: calc(var(--uib-speed) * 0.45);
  opacity: 0.4;
}
.pinwheel__line:nth-child(8) {
  animation-delay: calc(var(--uib-speed) * 0.525);
  opacity: 0.3;
}
.pinwheel__line:nth-child(9) {
  animation-delay: calc(var(--uib-speed) * 0.6);
  opacity: 0.2;
}
.pinwheel__line:nth-child(10) {
  animation-delay: calc(var(--uib-speed) * 0.675);
  opacity: 0.1;
}

@keyframes rotate {
  0% {
    transform: rotate(0deg);
  }

  100% {
    transform: rotate(180deg);
  }
}