/* Floating 3D scene canvas: fixed over the section backgrounds, under the nav, never interactive. */
.scene-3d { position: fixed; inset: 0; width: 100%; height: 100%; z-index: 40; pointer-events: none; contain: strict; opacity: 0; transition: opacity 0.6s var(--ease); }
.scene-3d.scene-ready { opacity: 1; }