/* Raytrace Audio Lab · 2D — all styles scoped under .rt-shell so they
   never leak into the shared site chrome (header, markdown body, etc). */
.rt-shell {
  --bg: #0a0e14;
  --panel: #121821;
  --panel-edge: #1f2b3a;
  --ink: #e6edf3;
  --dim: #6b7d91;
  --grid: #16202c;
  --player: #ffb454;
  --source: #59d4ff;
  --wall: #2d3a4d;
  --wall-edge: #45587150;
  --ray-direct: #ffb454;
  --ray-echo: #ff5e87;
  --ray-permeate: #7ee787;
  --rt-accent: #59d4ff;

  background: var(--bg);
  color: var(--ink);
  font-family: 'IBM Plex Mono', ui-monospace, 'SF Mono', Menlo, monospace;
  display: flex;
  flex-direction: column;
  touch-action: none;
  user-select: none;
  overflow: hidden;
  height: 100vh; /* replaced at runtime by app.js fitShell() */
}
.rt-shell * { margin: 0; padding: 0; box-sizing: border-box; -webkit-tap-highlight-color: transparent; }

/* ── Title row ───────────────────────────── */
.rt-shell .rt-header {
  padding: 0 14px;
  flex: 0 0 auto;
}
.rt-shell .titlebar {
  display: flex; align-items: baseline; gap: 8px;
  padding: 12px 2px 10px;
  border-bottom: 1px solid var(--panel-edge);
}
.rt-shell .titlebar h2 {
  font-size: 13px; letter-spacing: 2.5px; text-transform: uppercase;
  font-weight: 600;
}
.rt-shell .titlebar .tag {
  font-size: 9.5px; color: var(--dim); letter-spacing: 1.5px;
  margin-left: auto; text-transform: uppercase;
}

/* ── Stage ─────────────────────────────── */
.rt-shell #stage { flex: 1 1 auto; position: relative; min-height: 0; }
.rt-shell #stage canvas { display: block; width: 100%; height: 100%; }
.rt-shell .stage-hud {
  position: absolute; top: 10px; left: 12px; right: 12px;
  display: flex; justify-content: space-between; pointer-events: none;
  font-size: 9.5px; letter-spacing: 1px; color: var(--dim);
}
.rt-shell .mode-pill {
  pointer-events: auto;
  background: var(--panel); border: 1px solid var(--panel-edge);
  color: var(--rt-accent); padding: 5px 10px; border-radius: 20px;
  font-size: 9.5px; letter-spacing: 1.2px; text-transform: uppercase;
}

/* ── Readout strip ─────────────────────── */
.rt-shell .readout {
  flex: 0 0 auto;
  display: grid; grid-template-columns: repeat(3, 1fr);
  gap: 1px; background: var(--panel-edge);
  border-top: 1px solid var(--panel-edge);
}
.rt-shell .readout .cell {
  background: var(--panel); padding: 9px 11px;
}
.rt-shell .readout .k { font-size: 8.5px; letter-spacing: 1.3px; color: var(--dim); text-transform: uppercase; }
.rt-shell .readout .v { font-size: 15px; margin-top: 3px; font-variant-numeric: tabular-nums; }
.rt-shell .readout .v.muted { color: var(--dim); }

/* ── Controls ──────────────────────────── */
.rt-shell .controls {
  flex: 0 0 auto;
  padding: 12px 12px calc(12px + env(safe-area-inset-bottom));
  background: var(--panel);
  border-top: 1px solid var(--panel-edge);
  display: flex; flex-direction: column; gap: 11px;
}
.rt-shell .ray-toggles { display: flex; gap: 8px; }
.rt-shell .toggle {
  flex: 1; appearance: none; border: 1px solid var(--panel-edge);
  background: #0d131b; color: var(--dim);
  border-radius: 11px; padding: 11px 6px 10px;
  font-family: inherit; font-size: 10px; letter-spacing: 0.8px;
  display: flex; flex-direction: column; align-items: center; gap: 6px;
  transition: border-color .15s, color .15s, background .15s;
}
.rt-shell .toggle .dot { width: 9px; height: 9px; border-radius: 50%; background: currentColor; opacity: .35; transition: opacity .15s; }
.rt-shell .toggle .lbl { text-transform: uppercase; font-weight: 600; }
.rt-shell .toggle .sub { font-size: 8px; color: var(--dim); letter-spacing: .5px; }
.rt-shell .toggle[data-ray="direct"]   { --c: var(--ray-direct); }
.rt-shell .toggle[data-ray="echo"]     { --c: var(--ray-echo); }
.rt-shell .toggle[data-ray="permeate"] { --c: var(--ray-permeate); }
.rt-shell .toggle.on { color: var(--c); border-color: var(--c); background: #0d131b; }
.rt-shell .toggle.on .dot { opacity: 1; box-shadow: 0 0 10px currentColor; }

.rt-shell .action-row { display: flex; gap: 8px; }
.rt-shell .btn {
  flex: 1; appearance: none; font-family: inherit;
  border: 1px solid var(--panel-edge); background: #0d131b; color: var(--ink);
  border-radius: 10px; padding: 11px; font-size: 11px; letter-spacing: 1px;
  text-transform: uppercase; cursor: pointer;
}
.rt-shell .btn:active { background: #161f2b; }
.rt-shell .btn.primary { border-color: var(--rt-accent); color: var(--rt-accent); }
.rt-shell .hint {
  font-size: 9.5px; color: var(--dim); letter-spacing: .4px;
  text-align: center; line-height: 1.5;
}

/* ── Environment panel ─────────────────── */
.rt-shell .env-toggle {
  appearance: none; font-family: inherit; width: 100%;
  background: #0d131b; border: 1px solid var(--panel-edge); color: var(--dim);
  border-radius: 10px; padding: 9px 12px; cursor: pointer;
  display: flex; align-items: center; justify-content: space-between;
  font-size: 10px; letter-spacing: 1.4px; text-transform: uppercase;
}
.rt-shell .env-toggle .chev { transition: transform .2s; }
.rt-shell .env-toggle[aria-expanded="true"] { color: var(--rt-accent); border-color: var(--rt-accent); }
.rt-shell .env-toggle[aria-expanded="true"] .chev { transform: rotate(90deg); }
.rt-shell .env-panel[hidden] { display: none; }
.rt-shell .env-panel {
  display: flex; flex-direction: column; gap: 13px;
  padding: 13px 12px 14px; margin-top: -3px;
  background: #0d131b; border: 1px solid var(--panel-edge); border-radius: 10px;
}
.rt-shell .env-row { display: flex; flex-direction: column; gap: 8px; }
.rt-shell .env-row label {
  font-size: 10px; letter-spacing: .8px; color: var(--ink);
  display: flex; justify-content: space-between; align-items: center;
}
.rt-shell .env-row label span { color: var(--rt-accent); font-variant-numeric: tabular-nums; }
.rt-shell input[type="range"] {
  appearance: none; -webkit-appearance: none; width: 100%; height: 4px;
  background: var(--panel-edge); border-radius: 4px; outline: none;
}
.rt-shell input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none; width: 20px; height: 20px; border-radius: 50%;
  background: var(--rt-accent); cursor: pointer; box-shadow: 0 0 8px var(--rt-accent);
}
.rt-shell input[type="range"]::-moz-range-thumb {
  width: 20px; height: 20px; border: none; border-radius: 50%;
  background: var(--rt-accent); box-shadow: 0 0 8px var(--rt-accent);
}
.rt-shell .switch-row { flex-direction: row; align-items: center; justify-content: space-between; }
.rt-shell .switch {
  appearance: none; width: 46px; height: 26px; border-radius: 14px;
  background: var(--panel-edge); border: 1px solid var(--panel-edge);
  position: relative; transition: background .18s; cursor: pointer;
}
.rt-shell .switch .knob {
  position: absolute; top: 2px; left: 2px; width: 20px; height: 20px;
  border-radius: 50%; background: var(--dim); transition: transform .18s, background .18s;
}
.rt-shell .switch.on { background: #14323f; border-color: var(--rt-accent); }
.rt-shell .switch.on .knob { transform: translateX(20px); background: var(--rt-accent); box-shadow: 0 0 8px var(--rt-accent); }
.rt-shell .env-note { font-size: 9px; color: var(--dim); line-height: 1.5; letter-spacing: .3px; }