/* ------------------------------------------------------------------
   Particle / Starfield Background – Phase-4 delight layer
   ------------------------------------------------------------------ */

/*
   The effect renders two tiled radial-gradient layers that move slowly on the
   X/Y axis, creating the illusion of drifting particles / stars.  Because the
   colours use `currentColor` and transparency, they adapt automatically when
   the underlying theme tokens are tweaked.

   Usage: add a <div class="particle-bg"></div> as the first element inside
   <body>.  The element is positioned fixed with a negative z-index so it sits
   behind all content without affecting layout.
*/

.particle-bg {
  position: fixed;
  inset: 0;
  z-index: -1;               /* Behind every real element */
  pointer-events: none;      /* Ignore clicks */

  /* Dark fallback when CSS variables aren’t loaded yet */
  background-color: var(--dark, #000);

  /* Two radial-gradient dot patterns offset by half a tile */
  background-image:
    radial-gradient(circle, rgba(255, 255, 255, 0.12) 0%, transparent 40%),
    radial-gradient(circle, rgba(255, 255, 255, 0.07) 0%, transparent 40%);

  /* Size of a single dot (first layer) */
  background-size: 3px 3px, 3px 3px;

  /* Offset second layer so dots don’t overlap exactly */
  background-position: 0 0, 1.5px 1.5px;

  animation: particle-drift 60s linear infinite;
}

@keyframes particle-drift {
  from {
    background-position: 0 0, 1.5px 1.5px;
  }
  to {
    /* Move several screen widths to achieve a slow drift effect */
    background-position: 1000px 500px, 1001.5px 501.5px;
  }
}
