css 启动页 loading动画

<div class="index-html-loader">

  <div class="text">Loading...</div>
  <div class="horizontal">
    <div class="circlesup">
      <div class="circle"></div>
      <div class="circle"></div>
      <div class="circle"></div>
      <div class="circle"></div>
      <div class="circle"></div>
    </div>
    <div class="circlesdwn">
      <div class="circle"></div>
      <div class="circle"></div>
      <div class="circle"></div>
      <div class="circle"></div>
      <div class="circle"></div>
    </div>
  </div>
  <div class="vertical">
    <div class="circlesup">
      <div class="circle"></div>
      <div class="circle"></div>
      <div class="circle"></div>
      <div class="circle"></div>
      <div class="circle"></div>
    </div>
    <div class="circlesdwn">
      <div class="circle"></div>
      <div class="circle"></div>
      <div class="circle"></div>
      <div class="circle"></div>
      <div class="circle"></div>
    </div>
  </div>
</div>

<style>
  /* Start the loader code, first, let's align it the center of screen */
  .index-html-loader {
    position: absolute;
    top: 50%;
    left: 50%;
    -webkit-transform: translate(-50%, -50%);
    -moz-transform: translate(-50%, -50%);
    -mos-transform: translate(-50%, -50%);
    -o-transform: translate(-50%, -50%);
    transform: translate(-50%, -50%);
    text-align: center;
    /* disable selection and cursor changes */
    -webkit-touch-callout: none;
    -webkit-user-select: none;
    -khtml-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
    cursor: default;
  }

  /* Text align it the center of screen and connect the looped animation for 2 seconds */
  .index-html-loader .text {
    position: absolute;
    left: -1.3em;
    top: -1.7em;
    -webkit-animation: text 2s infinite;
    -moz-animation: text 2s infinite;
    -moz-animation: text 2s infinite;
    -ms-animation: text 2s infinite;
    -o-animation: text 2s infinite;
    animation: text 2s infinite;
  }

  /* Set for the first layer vertical position */
  .index-html-loader .vertical {
    position: absolute;
    top: -1.84em;
    left: -0.4em;
    -webkit-transform: rotate(90deg);
    -moz-transform: rotate(90deg);
    -ms-transform: rotate(90deg);
    -o-transform: rotate(90deg);
    transform: rotate(90deg);
  }

  /* Set for the second layer horizontal position */
  .index-html-loader .horizontal {
    position: absolute;
    top: 0em;
    left: 0em;
    -webkit-transform: rotate(0deg);
    -moz-transform: rotate(0deg);
    -ms-transform: rotate(0deg);
    -o-transform: rotate(0deg);
    transform: rotate(0deg);
  }

  /* The next two classes do mirror for animation */
  .index-html-loader .circlesup {
    position: absolute;
    top: -4.7em;
    right: 12.1em;
  }

  .index-html-loader .circlesdwn {
    position: absolute;
    top: 2.5em;
    right: -13.5em;
    -webkit-transform: rotate(180deg);
    -moz-transform: rotate(180deg);
    -ms-transform: rotate(180deg);
    -o-transform: rotate(180deg);
    transform: rotate(180deg);
  }

  /* Create a container for our circles, rotate it 45 degrees and set animation*/
  .index-html-loader .circle {
    position: absolute;
    width: 15em;
    height: 15em;
    -webkit-transform: rotate(45deg);
    -moz-transform: rotate(45deg);
    -ms-transform: rotate(45deg);
    -o-transform: rotate(45deg);
    transform: rotate(45deg);
    -webkit-animation: orbit 2s infinite;
    -moz-animation: orbit 2s infinite;
    -moz-animation: orbit 2s infinite;
    -ms-animation: orbit 2s infinite;
    -o-animation: orbit 2s infinite;
    animation: orbit 2s infinite;
    z-index: 5;
  }

  /* Style's of our circles */
  .index-html-loader .circle:after {
    content: '';
    position: absolute;
    width: 2em;
    height: 2em;
    -webkit-border-radius: 100%;
    -moz-border-radius: 100%;
    -ms-border-radius: 100%;
    -o-border-radius: 100%;
    border-radius: 100%;
    background: #13A3A5;
    /* Pick a color 1*/
  }

  .index-html-loader .circle:nth-child(2) {
    -webkit-animation-delay: 100ms;
    -moz-animation-delay: 100ms;
    -ms-animation-delay: 100ms;
    -o-animation-delay: 100ms;
    animation-delay: 100ms;
    z-index: 4;
  }

  .index-html-loader .circle:nth-child(2):after {
    background: #56bebf;
    /* Pick a color 2*/
    -webkit-transform: scale(0.8, 0.8);
    -moz-transform: scale(0.8, 0.8);
    -ms-transform: scale(0.8, 0.8);
    -o-transform: scale(0.8, 0.8);
    transform: scale(0.8, 0.8);
  }

  .index-html-loader .circle:nth-child(3) {
    -webkit-animation-delay: 225ms;
    -moz-animation-delay: 225ms;
    -ms-animation-delay: 225ms;
    -o-animation-delay: 225ms;
    animation-delay: 225ms;
    z-index: 3;
  }

  .index-html-loader .circle:nth-child(3):after {
    background: #ffa489;
    /* Pick a color 3*/
    -webkit-transform: scale(0.6, 0.6);
    -moz-transform: scale(0.6, 0.6);
    -ms-transform: scale(0.6, 0.6);
    -o-transform: scale(0.6, 0.6);
    transform: scale(0.6, 0.6);
  }

  .index-html-loader .circle:nth-child(4) {
    -webkit-animation-delay: 350ms;
    -moz-animation-delay: 350ms;
    -ms-animation-delay: 350ms;
    -o-animation-delay: 350ms;
    animation-delay: 350ms;
    z-index: 2;
  }

  .index-html-loader .circle:nth-child(4):after {
    background: #ff6d37;
    /* Pick a color 4*/
    -webkit-transform: scale(0.4, 0.4);
    -moz-transform: scale(0.4, 0.4);
    -ms-transform: scale(0.4, 0.4);
    -o-transform: scale(0.4, 0.4);
    transform: scale(0.4, 0.4);
  }

  .index-html-loader .circle:nth-child(5) {
    -webkit-animation-delay: 475ms;
    -moz-animation-delay: 475ms;
    -ms-animation-delay: 475ms;
    -o-animation-delay: 475ms;
    animation-delay: 475ms;
    z-index: 1;
  }

  .index-html-loader .circle:nth-child(5):after {
    background: #DB2F00;
    /* Pick a color 5*/
    -webkit-transform: scale(0.2, 0.2);
    -moz-transform: scale(0.2, 0.2);
    -ms-transform: scale(0.2, 0.2);
    -o-transform: scale(0.2, 0.2);
    transform: scale(0.2, 0.2);
  }

  /* Animation keys */
  
  @keyframes orbit {
    0% {
      transform: rotate(45deg);
    }

    5% {
      transform: rotate(45deg);
      animation-timing-function: ease-out;
    }

    70% {
      transform: rotate(405deg);
      animation-timing-function: ease-in;
    }

    100% {
      transform: rotate(405deg);
    }
  }
  
  @keyframes text {
    0% {
      transform: scale(0.2, 0.2);
      animation-timing-function: ease-out;
    }

    50% {
      transform: scale(1, 1);
      animation-timing-function: ease-out;
    }

    60% {
      transform: scale(1, 1);
      animation-timing-function: ease-out;
    }

    100% {
      transform: scale(0.2, 0.2);
    }
  }
</style>