/* ============================================================
   atmos.css
   氛围层 · 顶部聚光 / 暗角 / feTurbulence 细颗粒
   ============================================================ */

/* ---------- 氛围层：顶部聚光 + 暗角 + 细颗粒 ---------- */
.atmos{position:absolute;inset:0;pointer-events:none;z-index:0}
.atmos--glow{
  background:
    radial-gradient(72% 28% at 50% -4%, rgba(255,255,255,.095), rgba(255,255,255,0) 72%),
    radial-gradient(140% 75% at 50% 112%, rgba(255,255,255,.03), transparent 70%);
}
.atmos--vig{background:radial-gradient(130% 92% at 50% 44%, rgba(0,0,0,0) 44%, rgba(0,0,0,.58) 100%)}
.atmos--grain{
  opacity:.05;
  mix-blend-mode:soft-light;
  background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='180' height='180'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.85' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='180' height='180' filter='url(%23n)'/%3E%3C/svg%3E");
  background-size:180px 180px;
}