.concept-stage {
  position: absolute;
  inset: 0;
  display: grid;
  align-content: center;
  gap: 18px;
  padding: 34px 24px;
}
.concept-stage[hidden],
.scene-wrap.is-concept > #world,
.scene-wrap.is-concept > :not(.concept-stage) {
  display: none;
}
.concept-stage h3 {
  margin: 0;
  font-size: clamp(17px, 3vw, 25px);
}
.concept-stage p {
  margin: 6px 0 0;
  line-height: 1.5;
}
.concept-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 8px;
}
.concept-example {
  min-width: 0;
  min-height: 61px;
  border: 1px solid #cad7c7;
  border-radius: 10px;
  background: #fafcf5;
  color: #25483d;
  font: inherit;
  font-size: .85rem;
  font-weight: 700;
  padding: 8px 4px;
  cursor: pointer;
}
.concept-example[aria-pressed="true"] {
  border-color: #52775a;
  background: #e2edcf;
  box-shadow: inset 0 0 0 1px #52775a;
}
.concept-example svg {
  width: 32px;
  height: 25px;
  display: block;
  margin: 0 auto 4px;
}
.concept-result {
  background: #fffefa;
  border: 1px solid #cad7c7;
  border-radius: 12px;
  min-height: 96px;
  padding: 12px 14px;
  font-size: .88rem;
}
.concept-result strong {
  display: block;
  font-size: 1rem;
}
.demo-tag[href] { color: inherit; text-decoration: none; }
#compare { flex-wrap: wrap; }
@media (max-width: 480px) {
  .concept-stage { gap: 11px; padding: 12px; }
  .concept-stage p { font-size: .82rem; }
  .concept-example { min-height: 50px; font-size: .72rem; }
  .concept-result { min-height: 68px; padding: 8px 10px; }
}