fix(about): prevent overlap and blend scene background

src/components/RiverJourney.module.css

@@ -150,7 +150,7 @@
   }
 }
 
-@media (max-width: 760px) {
+@media (max-width: 900px) {
   .journeySection {
     height: auto;
     min-height: 70rem;

src/components/scenes/AboutRiverScene.tsx

@@ -42,7 +42,11 @@ const createAboutScene: SceneFactory = ({ pointer, theme, reduceMotion }) => {
 
   const ground = new THREE.Mesh(
     new THREE.PlaneGeometry(60, 60),
-    new THREE.MeshStandardMaterial({ color: palette.ground, roughness: 1 }),
+    new THREE.ShadowMaterial({
+      color: 0x000000,
+      opacity: theme === 'dark' ? 0.2 : 0.08,
+      transparent: true,
+    }),
   );
   ground.rotation.x = -Math.PI / 2;
   ground.position.y = -0.32;