supabase/apps/docs/styles/loading-beam.css

@property --loading-beam-x {
  syntax: '<number>';
  initial-value: 0.5;
  inherits: true;
}

@keyframes loading-beam-sweep {
  0%,
  100% {
    --loading-beam-x: 0;
  }
  50% {
    --loading-beam-x: 1;
  }
}

@layer components {
  .loading-beam {
    --loading-beam-color: var(--foreground-default);
    --loading-beam-half: 100px;
    --loading-beam-center: calc(
      var(--loading-beam-half) + var(--loading-beam-x) * (100% - var(--loading-beam-half) * 2)
    );
    position: absolute;
    inset: auto 0 0;
    height: 16px;
    overflow: hidden;
    pointer-events: none;
    opacity: 0;
    transition: opacity 150ms ease-out;
    animation: loading-beam-sweep 2s ease-in-out -0.25s infinite paused;
  }

  .loading-beam[data-direction='backward'] {
    animation-delay: -1.25s;
  }

  .loading-beam[data-active] {
    opacity: 1;
    transition-duration: 250ms;
    animation-play-state: running;
  }

  .loading-beam::before,
  .loading-beam::after {
    content: '';
    position: absolute;
  }

  .loading-beam::before {
    inset: 0 0 -8px;
    filter: blur(4px);
    background: radial-gradient(
      120px 12px at var(--loading-beam-center) calc(100% - 8px),
      color-mix(in oklch, var(--loading-beam-color) 3.2%, transparent),
      transparent
    );
  }

  .loading-beam::after {
    inset: auto 0 0;
    height: 1px;
    background: radial-gradient(
      var(--loading-beam-half) 4px at var(--loading-beam-center) 100%,
      color-mix(in oklch, var(--loading-beam-color) 44.5%, transparent),
      color-mix(in oklch, var(--loading-beam-color) 16%, transparent) 45%,
      transparent
    );
  }

  @media (prefers-reduced-motion: reduce) {
    .loading-beam {
      animation: none;
    }
  }
}