#nb4-dfb-background {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  z-index: -1;
  overflow: hidden;
  pointer-events: none;
  background: #111;
}

#nb4-dfb-background .nb4-dfb-slide,
#nb4-dfb-background .nb4-dfb-overlay {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

#nb4-dfb-background .nb4-dfb-slide {
  background-repeat: no-repeat;
  background-size: cover;
  background-position: center center;
  opacity: 0;
  transform: scale(1.01);
  transition: opacity var(--nb4-dfb-transition, 1400ms) ease;
  will-change: opacity;
}

#nb4-dfb-background .nb4-dfb-slide.is-visible {
  opacity: 1;
}

#nb4-dfb-background .nb4-dfb-overlay {
  z-index: 3;
  background: var(--nb4-dfb-overlay-color, #000);
  opacity: var(--nb4-dfb-overlay-opacity, .35);
}

html:has(body.nb4-dfb-active),
body.nb4-dfb-active {
  background: transparent !important;
}

body.nb4-dfb-active #page-container {
  background-color: transparent;
}

@media (prefers-reduced-motion: reduce) {
  #nb4-dfb-background .nb4-dfb-slide {
    transition: none !important;
  }
}