tabler/site/styles/_expandable.scss

.expandable {
  --expandable-shadow-start: 50%;
  position: relative;
  height: 35rem;
  overflow: hidden;
  background: repeat-x top center;

  &:after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 1;
    background: linear-gradient(to bottom, rgba(var(--section-bg-rgb), 0) var(--expandable-shadow-start), rgba(var(--section-bg-rgb), 1) 100%);
    pointer-events: none;
  }

  &:hover {
    .expandable-hover {
      opacity: 1;
    }
  }
}

.expandable-hover {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  backdrop-filter: blur(4px);
  opacity: 0;
  transition: $transition-duration opacity;
}

.expandable-lg {
  height: 50rem;
}

.expandable-emails {
  --expandable-shadow-start: 50%;
  background-image: url(../public/img/tabler-emails/emails-bg.png);
  background-size: 2176px auto;
  background-repeat: no-repeat;

  @include media-retina {
    background-image: url(../public/img/tabler-emails/emails-bg.png);
  }

  @include media-breakpoint-down(lg) {
    background-size: (2176px / 2) auto;
    height: 20rem;
  }
}