.shell {
  display: grid;
  min-height: calc(100dvh - var(--chrome-height));
  grid-template-columns: minmax(0, 1fr) 400px;
}

.stage { position: relative; min-height: 70dvh; }

.stage canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
  touch-action: none;
  cursor: grab;
}

.stage canvas:active { cursor: grabbing; }

.stage-head, .caption {
  position: absolute;
  z-index: 1;
  left: 0;
  pointer-events: none;
}

.stage-head { top: 0; padding: 28px 32px; }

.caption {
  bottom: 18px;
  margin: 0;
  padding: 0 32px;
  font-family: var(--font-display);
  font-size: 22px;
}

.stage:has(.teach:not([hidden])) .caption { display: none; }

h1 {
  margin: 4px 0 0;
  font-family: var(--font-display);
  font-weight: 520;
  font-size: 64px;
  letter-spacing: -0.03em;
}

.eyebrow {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--muted);
}

.panel {
  border-left: 1px solid var(--line);
  padding: 16px 18px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  background: var(--panel);
  overflow: auto;
}

.note {
  margin: 0;
  font-size: 14px;
  line-height: 1.4;
  color: var(--muted);
}

.field-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}

.field-head button {
  padding: 4px 8px;
  font-size: 12px;
  letter-spacing: 0;
  text-transform: none;
}

@media (max-width: 900px) {
  .shell { grid-template-columns: 1fr; }
  .stage { min-height: 68dvh; }
  .panel { border-left: 0; border-top: 1px solid var(--line); }
  h1 { font-size: 48px; }
}