css制作收缩圆环旋转效果实例代码

<style>
body {
  background: #372940;
}
.demo {
  position: relative;
  margin: 120px auto;
  width: 150px;
}
.loader {
  position: absolute;
  opacity: .7;
}
.loader circle {
  -webkit-animation: draw 4s infinite ease-in-out;
          animation: draw 4s infinite ease-in-out;
  -webkit-transform-origin: center;
          transform-origin: center;
  -webkit-transform: rotate(-90deg);
          transform: rotate(-90deg);
}
.loader-2 circle,
.loader-6 circle {
  -webkit-animation-delay: 1s;
          animation-delay: 1s;
}
.loader-7 circle {
  -webkit-animation-delay: 2s;
          animation-delay: 2s;
}
.loader-4 circle,
.loader-8 circle {
  -webkit-animation-delay: 3s;
          animation-delay: 3s;
}
.loader-3 {
  left: -150px;
  -webkit-transform: rotateY(180deg);
          transform: rotateY(180deg);
}
.loader-6,
.loader-7,
.loader-8 {
  left: -150px;
  -webkit-transform: rotateX(180deg) rotateY(180deg);
          transform: rotateX(180deg) rotateY(180deg);
}
.loader-5 circle {
  opacity: .2;
}
@-webkit-keyframes draw {
  50% {
    stroke-dashoffset: 0;
    -webkit-transform: scale(0.5);
            transform: scale(0.5);
  }
}
@keyframes draw {
  50% {
    stroke-dashoffset: 0;
    -webkit-transform: scale(0.5);
            transform: scale(0.5);
  }
}
  </style>

<div class="demo">
  <svg class="loader">
    <filter id="blur">
      <fegaussianblur in="SourceGraphic" stddeviation="2"></fegaussianblur>
    </filter>
    <circle cx="75" cy="75" r="60" fill="transparent" stroke="#F4F519" stroke-width="6" stroke-linecap="round" stroke-dasharray="385" stroke-dashoffset="385" filter="url(#blur)"></circle>
  </svg>
  <svg class="loader loader-2">
    <circle cx="75" cy="75" r="60" fill="transparent" stroke="#DE2FFF" stroke-width="6" stroke-linecap="round" stroke-dasharray="385" stroke-dashoffset="385" filter="url(#blur)"></circle>
  </svg>
  <svg class="loader loader-3">
    <circle cx="75" cy="75" r="60" fill="transparent" stroke="#FF5932" stroke-width="6" stroke-linecap="round" stroke-dasharray="385" stroke-dashoffset="385" filter="url(#blur)"></circle>
  </svg>
  <svg class="loader loader-4">
    <circle cx="75" cy="75" r="60" fill="transparent" stroke="#E97E42" stroke-width="6" stroke-linecap="round" stroke-dasharray="385" stroke-dashoffset="385" filter="url(#blur)"></circle>
  </svg>
  <svg class="loader loader-5">
    <circle cx="75" cy="75" r="60" fill="transparent" stroke="white" stroke-width="6" stroke-linecap="round" filter="url(#blur)"></circle>
  </svg>
  <svg class="loader loader-6">
    <circle cx="75" cy="75" r="60" fill="transparent" stroke="#00DCA3" stroke-width="6" stroke-linecap="round" stroke-dasharray="385" stroke-dashoffset="385" filter="url(#blur)"></circle>
  </svg>
  <svg class="loader loader-7">
    <circle cx="75" cy="75" r="60" fill="transparent" stroke="purple" stroke-width="6" stroke-linecap="round" stroke-dasharray="385" stroke-dashoffset="385" filter="url(#blur)"></circle>
  </svg>
  <svg class="loader loader-8">
    <circle cx="75" cy="75" r="60" fill="transparent" stroke="#AAEA33" stroke-width="6" stroke-linecap="round" stroke-dasharray="385" stroke-dashoffset="385" filter="url(#blur)"></circle>
  </svg>
</div>