Overleaf/services/web/frontend/stylesheets/bootstrap-5/pages/editor.scss

@keyframes blink {
  0% {
    opacity: 0.2;
  }

  20% {
    opacity: 1;
  }

  100% {
    opacity: 0.2;
  }
}

.loading-screen-brand-container {
  width: 15%;
  min-width: 200px;
  text-align: center;
}

.loading-screen-brand {
  position: relative;
  width: 100%;
  padding-top: 115.44%;
  height: 0;
  background: url(../../../../public/img/ol-brand/overleaf-o-grey.svg) no-repeat
    bottom / 100%;

  &::after {
    content: '';
    position: absolute;
    height: inherit;
    right: 0;
    bottom: 0;
    left: 0;
    background: url(../../../../public/img/ol-brand/overleaf-o.svg) no-repeat
      bottom / 100%;
    transition: height 0.5s;
  }
}

.loading-screen-label {
  margin: 0 !important;
  padding-top: var(--spacing-09);
  font-family: $font-family-serif;
  font-size: var(--font-size-07) !important;
  color: var(--content-secondary);
}

.loading-screen-ellip {
  animation: blink 1.4s both infinite;

  &:nth-child(2) {
    animation-delay: 0.2s;
  }

  &:nth-child(3) {
    animation-delay: 0.4s;
  }
}