body {
  margin: 0;
  padding: 0;
}

/* 核心：圆的速度和转向不同，形成cuowei */
span:nth-child(1) {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);

  width: 60px;
  height: 60px;

  border: 6px solid #262626;
  border-top: 6px solid transparent;
  border-radius: 50%;
  animation: animate2 2s linear infinite;
}

span:nth-child(2) {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);

  width: 100px;
  height: 100px;

  border: 6px solid #262626;
  border-bottom: 6px solid transparent;
  border-radius: 50%;
  animation: animate1 1s linear infinite;
}

span:nth-child(3) {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);

  width: 20px;
  height: 20px;

  border: 6px solid #262626;
  border-bottom: 6px solid transparent;
  border-radius: 50%;
  animation: animate1 1s linear infinite;
}

@keyframes animate1 {
  0% {
    transform: translate(-50%, -50%) rotate(0);
  }
  100% {
    transform: translate(-50%, -50%) rotate(360deg);
  }
}

@keyframes animate2 {
  0% {
    transform: translate(-50%, -50%) rotate(0);
  }
  100% {
    transform: translate(-50%, -50%) rotate(-360deg);
  }
}