/* ─────────────────────────────────────────────────────────────
   Shared cosmic backdrop — twinkling starfield + drifting nebula.

   Every hub page used to carry its own copy of this. The geometry
   and the animations now live here once; each page still picks its
   own palette by setting the custom properties below, and keeps its
   own `.nebula b:nth-child()` rules since the blob layout is part of
   that page's design.

   Markup expected:
     <div class="stars" aria-hidden="true"></div>
     <div class="nebula" aria-hidden="true"><b></b><b></b><b></b></div>
   ───────────────────────────────────────────────────────────── */

:root {
  --star-warm: #cfe6ff;  /* star at 27% 78% */
  --star-glow: #fce8a8;  /* star at 58% 64% */
  --star-cool: #d4c2ff;  /* star at 84% 82% */
  --star-pale: #aee0ff;  /* star at  6% 56% */
  --nebula-opacity: 0.32;
}

.stars {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  overflow: hidden;
}

.stars::before,
.stars::after {
  content: "";
  position: absolute;
  inset: -50%;
  background-image:
    radial-gradient(1.5px 1.5px at 13% 22%, #fff, transparent 60%),
    radial-gradient(1px 1px     at 27% 78%, var(--star-warm), transparent 60%),
    radial-gradient(2px 2px     at 41% 14%, #fff, transparent 60%),
    radial-gradient(1px 1px     at 58% 64%, var(--star-glow), transparent 60%),
    radial-gradient(1.5px 1.5px at 72% 36%, #fff, transparent 60%),
    radial-gradient(1px 1px     at 84% 82%, var(--star-cool), transparent 60%),
    radial-gradient(1.2px 1.2px at 92% 12%, #fff, transparent 60%),
    radial-gradient(1px 1px     at  6% 56%, var(--star-pale), transparent 60%);
  background-size: 100% 100%;
  animation: twinkle 4s ease-in-out infinite alternate, drift 140s linear infinite;
  opacity: 0.75;
}

.stars::after {
  animation: twinkle 6s ease-in-out 0.8s infinite alternate, drift 220s linear reverse infinite;
  opacity: 0.5;
  filter: blur(0.4px);
}

@keyframes twinkle {
  from { opacity: 0.3; }
  to   { opacity: 0.95; }
}

@keyframes drift {
  from { transform: translate3d(0, 0, 0); }
  to   { transform: translate3d(-3%, -2%, 0); }
}

.nebula {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  overflow: hidden;
}

.nebula b {
  position: absolute;
  border-radius: 50%;
  filter: blur(60px);
  opacity: var(--nebula-opacity);
  animation: nebulaFloat 18s ease-in-out infinite alternate;
}

@keyframes nebulaFloat {
  from { transform: translate(0, 0) scale(1); }
  to   { transform: translate(40px, -30px) scale(1.12); }
}

/* Respect a reduced-motion preference: keep the art, drop the drift. */
@media (prefers-reduced-motion: reduce) {
  .stars::before,
  .stars::after,
  .nebula b {
    animation: none;
  }
}