improve app ui for demo

Pocket Poster/Extensions/MaterialView.swift

@@ -0,0 +1,24 @@
+//
+//  MaterialView.swift
+//  Pocket Poster
+//
+//  Created by lemin on 5/31/25.
+//
+
+import SwiftUI
+
+struct MaterialView: UIViewRepresentable {
+    let material: UIBlurEffect.Style
+
+    init(_ material: UIBlurEffect.Style) {
+        self.material = material
+    }
+
+    func makeUIView(context: Context) -> UIVisualEffectView {
+        UIVisualEffectView(effect: UIBlurEffect(style: material))
+    }
+
+    func updateUIView(_ uiView: UIVisualEffectView, context: Context) {
+        uiView.effect = UIBlurEffect(style: material)
+    }
+}