/* Shared room: the original illustration remains the no-JS/GPU fallback. */
body.bg-game { isolation: isolate; }
body.bg-game.bg-reader {
  background: #164e58 url('bacavia-world/library-interior.webp') center top/cover fixed !important;
}
.bg-library-scene {
  position: fixed; inset: 0; z-index: -1; pointer-events: none;
  overflow: hidden; background: url('bacavia-world/library-interior.webp') center top/cover;
}
.bg-library-scene canvas { display: block; width: 100%; height: 100%; }
.bg-library-scene canvas[hidden] { display: none; }
.bg-reader .bg-library-scene::after {
  content: ''; position: absolute; inset: 0; background: #102f393b;
}
.bg-reader[data-theme=dark] .bg-library-scene::after { background: #081c2a80; }
.bg-hud .bg-wind {
  display: inline-flex; align-items: center; justify-content: center;
  min-height: 44px; width: auto; margin: 0; padding: 8px 12px;
  border: 1px solid #dfbd81; border-radius: 12px;
  background: #fff9ed; color: #164b57; font: 700 12px system-ui,sans-serif;
  text-transform: none; letter-spacing: normal; cursor: pointer;
}
.bg-hud .bg-wind[aria-pressed=true] { background: #e4f1eb; color: #007985; }
.bg-hud .bg-wind[hidden] { display: none; }
@media (prefers-reduced-motion: reduce) {
  .bg-library-scene canvas { display: none; }
}