$ball-color:#30a1f2;
$ball-size:.15rem;
$ball-margin:.02rem;
$loader-radius:.25rem;

@function delay($interval, $count, $index) {
  @return ($index * $interval) - ($interval * $count);
}

@keyframes ball-spin-fade-loader {
  50% {
    opacity: 0.3;
    transform: scale(0.4);
  }
  100% {
    opacity: 1;
    transform: scale(1);
  }
}
@mixin ball-spin-fade-loader($n:8,$start:1){
  @for $i from $start through $n {
    > div:nth-child(#{$i}) {
      $quarter: ($loader-radius/2) + ($loader-radius/5.5);

      @if $i == 1 {
        top: $loader-radius;
        left: 0;
      } @else if $i == 2 {
        top: $quarter;
        left: $quarter;
      } @else if $i == 3 {
        top: 0;
        left: $loader-radius;
      } @else if $i == 4 {
        top: -$quarter;
        left: $quarter;
      } @else if $i == 5 {
        top: -$loader-radius;
        left: 0;
      } @else if $i == 6 {
        top: -$quarter;
        left: -$quarter;
      } @else if $i == 7 {
        top: 0;
        left: -$loader-radius;
      } @else if $i == 8 {
        top: $quarter;
        left: -$quarter;
      }
      animation: ball-spin-fade-loader 1s delay(0.12s, $n, $i - 1) infinite linear;
    }
  }
}

.loading-box{
  align-items: center;
  justify-content: center;
  position: fixed;
  left: 0;
  right: 0;
  top: 0;
  bottom: 0;
  z-index: 9999;
  &-bg{
    position: absolute;
    left: 0;
    top: 0;
    height: 100%;
    width: 100%;
    background: rgba(255,255,255,.7);
  }
  &-inner{
    @include ball-spin-fade-loader();
    position: relative;
    >div{
      position: absolute;
      width: $ball-size;
      height: $ball-size;
      border-radius: 50%;
      margin: $ball-margin;
      background-color: $ball-color;
      animation-fill-mode: both;
    }
  }
}