@keyframes sts-loading-animation {
  0% {
    top: 28px;
    left: 28px;
    width: 0;
    height: 0;
    opacity: 1;
  }
  100% {
    top: -1px;
    left: -1px;
    width: 58px;
    height: 58px;
    opacity: 0;
  }
}

.sts-loading {
  position: absolute;
  display: flex;
  background: rgba(20, 30, 48, 0.2);
  background: -webkit-linear-gradient(to right, rgba(20, 30, 48, 0.2), rgba(36, 59, 85, 0.2));
  background: linear-gradient(to right, rgba(20, 30, 48, 0.2), rgba(36, 59, 85, 0.2));
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 999;
  justify-content: center;
  align-items: center;
}

.sts-loading > span {
  display: inline-block;
  position: relative;
  width: 64px;
  height: 64px;
}

.sts-loading > span:before,
.sts-loading > span:after {
  content: '';
  position: absolute;
  border: 4px solid #fff;
  opacity: 1;
  border-radius: 50%;
  animation: sts-loading-animation 1s cubic-bezier(0, 0.2, 0.8, 1) infinite;
}

.sts-loading > span:after {
  animation-delay: -0.5s;
}