#loading-wrapper {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgb(255, 255, 255);  /* 初始为白色 */
  z-index: 199999;
  transition: all 0.8s ease;
}

.loader, .loader:before, .loader:after {
border-radius: 50%;
width: 2.5em;
height: 2.5em;
animation-fill-mode: both;
animation: bblFadInOut 1.8s infinite ease-in-out;
}
.loader {
color: #FFF;
font-size: 7px;
position: fixed;
top: 50%;
left: 50%;
transform: translate(-50%, -50%);
text-indent: -9999em;
transform: translateZ(0);
animation-delay: -0.16s;
}
.loader:before,
.loader:after {
content: '';
position: absolute;
top: 0;
}
.loader:before {
left: -3.5em;
animation-delay: -0.32s;
}
.loader:after {
left: 3.5em;
}

@keyframes bblFadInOut {
0%, 80%, 100% { box-shadow: 0 2.5em 0 -1.3em }
40% { box-shadow: 0 2.5em 0 0 }
}