discourse/app/assets/stylesheets/common/components/conditional-loading-section.scss

.conditional-loading-section {
  &.is-loading {
    padding: 2em;
    margin: 1em;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--primary-very-low);
    flex-direction: column;

    .title {
      font-size: var(--font-up-1);
      font-weight: 700;
    }
  }

  &:not(.is-loading) {
    animation: fadein 0.5s;
  }

  @keyframes fadein {
    from {
      opacity: 0;
    }
    to {
      opacity: 1;
    }
  }
}