[gemini] Re-implement glass floor sections (#483) (#492)

app.js

@@ -303,10 +303,13 @@ function createLighting() {
 // ═══ FLOOR ═══
 function createFloor() {
   const platGeo = new THREE.CylinderGeometry(25, 25, 0.3, 6);
-  const platMat = new THREE.MeshStandardMaterial({
-    color: 0x0a0f1a,
-    roughness: 0.8,
-    metalness: 0.3,
+  const platMat = new THREE.MeshPhysicalMaterial({
+    color: NEXUS.colors.bg,
+    transparent: true,
+    opacity: 0.2,
+    transmission: 0.9,
+    roughness: 0.1,
+    metalness: 0.2,
   });
   const platform = new THREE.Mesh(platGeo, platMat);
   platform.position.y = -0.15;