/* The fixed atmosphere behind everything: dust, grid, notes, moods, sunlit stage. */

/* ---------- designed atmosphere (no photos) ---------- */
#stage {
  position: fixed; inset: 0; z-index: 0; pointer-events: none; overflow: hidden;
  background:
    radial-gradient(ellipse 90% 70% at 50% 0%, rgba(70, 58, 40, 0.5), transparent 58%),
    radial-gradient(ellipse 80% 50% at 80% 100%, rgba(30, 44, 30, 0.45), transparent 50%),
    radial-gradient(ellipse 120% 90% at 50% 50%, transparent 55%, rgba(0,0,0,0.55) 100%),
    linear-gradient(180deg, #221e18 0%, var(--seam) 50%, #14120e 100%);
  transition: opacity 1.8s ease;
}
#stage .dust {
  position: absolute; inset: 0;
  background-image:
    radial-gradient(1px 1px at 12% 22%, rgba(255,236,200,0.35), transparent),
    radial-gradient(1px 1px at 28% 68%, rgba(255,236,200,0.2), transparent),
    radial-gradient(1.5px 1.5px at 63% 18%, rgba(255,240,210,0.28), transparent),
    radial-gradient(1px 1px at 81% 46%, rgba(210,230,180,0.22), transparent),
    radial-gradient(1px 1px at 44% 82%, rgba(255,236,200,0.18), transparent),
    radial-gradient(1.5px 1.5px at 72% 74%, rgba(255,220,160,0.16), transparent);
  opacity: 0.45;
  animation: dust-drift 28s linear infinite;
}
@keyframes dust-drift {
  from { transform: translate3d(0, 0, 0); }
  to { transform: translate3d(-18px, -28px, 0); }
}
.grid {
  position: absolute; inset: 0;
  background-image:
    linear-gradient(var(--line) 1px, transparent 1px),
    linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 48px 48px;
  opacity: 0.28;
  transition: opacity 2.4s ease;
}
.paper-wash {
  position: absolute; inset: -10%;
  background:
    radial-gradient(ellipse 80% 60% at 30% 20%, rgba(212,196,138,0.18), transparent 55%),
    radial-gradient(ellipse 70% 50% at 80% 70%, rgba(107,138,154,0.12), transparent 50%),
    radial-gradient(ellipse 50% 40% at 50% 110%, rgba(80, 110, 50, 0.08), transparent 55%),
    linear-gradient(180deg, rgba(232,228,220,0.06), transparent 40%, rgba(13,13,15,0.22));
  opacity: 0.8;
  transition: opacity 2.4s ease;
}
.helix {
  position: absolute; left: 50%; top: 10%; width: 120px; height: 80%;
  transform: translateX(-50%);
  opacity: 0.22; transition: opacity 2.4s ease;
}
.helix span {
  position: absolute; left: 0; right: 0; height: 2px;
  background: linear-gradient(90deg, transparent, var(--blue), var(--yellow), transparent);
  transform-origin: center;
}
.notes {
  position: absolute; inset: 0; transition: opacity 2.4s ease;
}
.note {
  position: absolute; width: 56px; height: 56px;
  background:
    linear-gradient(135deg, rgba(255,255,255,0.2), transparent 40%),
    var(--sticky);
  opacity: 0.55;
  box-shadow: 2px 3px 6px rgba(0,0,0,0.35), inset 0 0 0 1px rgba(255,255,255,0.15);
  transform: rotate(var(--r, -4deg));
  border-radius: 1px 1px 2px 1px;
}
.note.ruled {
  background:
    repeating-linear-gradient(180deg, transparent 0 11px, rgba(90,70,40,0.12) 11px 12px),
    linear-gradient(135deg, #f3e7b8, #d4c48a);
  width: 72px; height: 88px;
}
.note.tape::before {
  content: ""; position: absolute; left: 30%; top: -6px; width: 40%; height: 12px;
  background: rgba(230,220,180,0.55); transform: rotate(-2deg);
  box-shadow: 0 1px 2px rgba(0,0,0,0.2);
}
.note .scribble {
  position: absolute; inset: 8px 6px; font-family: var(--mono);
  font-size: 7px; line-height: 1.35; color: rgba(40,30,20,0.45);
  overflow: hidden; word-break: break-all;
}
.threads {
  position: absolute; inset: 0; opacity: 0.25; transition: opacity 2.4s ease;
}
.threads i {
  position: absolute; height: 1px; left: 0; right: 0;
  background: linear-gradient(90deg, transparent, rgba(201,185,138,0.35), rgba(158,184,184,0.35), transparent);
}
.threads b {
  position: absolute; width: 1px; top: 0; bottom: 0;
  background: linear-gradient(180deg, transparent, rgba(158,184,184,0.3), transparent);
}
.orbit {
  position: absolute; inset: 15%; border: 1px solid rgba(107,138,154,0.2);
  border-radius: 50%; opacity: 0.15; transition: opacity 2.4s ease;
}
.orbit::before {
  content: ""; position: absolute; width: 8px; height: 8px; border-radius: 50%;
  background: var(--yellow); top: 0; left: 50%; transform: translate(-50%, -50%);
}

/* mood via body class — soft blends, nothing hard-cuts */
body.mood-science .grid { opacity: 0.4; background-size: 42px 42px; }
body.mood-science .helix { opacity: 0.28; }
body.mood-science .notes { opacity: 0.85; }
body.mood-science .threads { opacity: 0.2; }
body.mood-science .orbit { opacity: 0.1; }
body.mood-science .paper-wash { opacity: 0.85; }

body.mood-clinic .grid { opacity: 0.28; background-size: 56px 32px; }
body.mood-clinic .helix { opacity: 0.12; }
body.mood-clinic .notes { opacity: 0.4; }
body.mood-clinic .threads { opacity: 0.45; }
body.mood-clinic .orbit { opacity: 0.22; }
body.mood-clinic .paper-wash { opacity: 0.45; }

body.mood-human .grid { opacity: 0.16; }
body.mood-human .helix { opacity: 0.08; }
body.mood-human .notes { opacity: 0.28; }
body.mood-human .threads { opacity: 0.55; }
body.mood-human .orbit { opacity: 0.35; }
body.mood-human .paper-wash { opacity: 0.35; }

/* sunlight / overgrowth slowly lifts the whole atmosphere */
body.growth-vines #stage .paper-wash { opacity: 0.9; }
body.growth-sun #stage {
  background:
    radial-gradient(ellipse 90% 70% at 70% 0%, rgba(255, 214, 120, 0.22), transparent 55%),
    radial-gradient(ellipse 80% 50% at 20% 100%, rgba(90, 140, 50, 0.18), transparent 50%),
    #1a1810;
}
body.growth-sun #stage .paper-wash { opacity: 1; }
body.growth-sun .grid { opacity: 0.1; }