matomo/plugins/CoreHome/stylesheets/matomo-loader.less

.matomo-loader {
  width: 16px;
  height: 11px;
  display: inline-block;
  position: relative;

  span {
    background: #f0f0f0;
    position: absolute;
    top: 2px;
    animation: matomo-loader 1s infinite ease-in-out;
    width: 2px;
    height: 5px;
    display: inline-block;
    border: 1px solid #f5f5f5;
    box-sizing: content-box;

    &:nth-child(1) {
      left: 0;
      display: inline-block;
    }

    &:nth-child(2) {
      left: 6px;
      display: inline-block;
      animation-delay: 0.15s;
    }

    &:nth-child(3) {
      left: 12px;
      animation-delay: 0.35s;
      display: inline-block;
    }
  }
}

@keyframes matomo-loader {
  0%, 75%, 100% {
    top: 2px;
    height: 5px;
  }
  25% {
    top: 0;
    height: 9px;
    border-color: #bbb;
    background: #ccc;
  }
}