diff --git a/Sources/FloatingMonitor/App/FloatingWindowController.swift b/Sources/FloatingMonitor/App/FloatingWindowController.swift
index 1935921..400eab6 100644
--- a/Sources/FloatingMonitor/App/FloatingWindowController.swift
+++ b/Sources/FloatingMonitor/App/FloatingWindowController.swift
@@ -5,6 +5,7 @@ import SwiftUI
 final class FloatingWindowController: NSWindowController {
     private var hostingView: NSHostingView<ContentView>?
     private var visualEffect: NSVisualEffectView!
+    private let tinyAlphaBackground = NSColor.white.withAlphaComponent(0.00001)
 
     private let debugLogPath = NSHomeDirectory() + "/Desktop/fm_debug.log"
 
@@ -132,20 +133,45 @@ final class FloatingWindowController: NSWindowController {
 
     private func applyBackdropEnabled(_ enabled: Bool) {
         guard let ve = visualEffect else { return }
+        guard let window = window else { return }
         if enabled {
+            ve.isHidden = false
+            ve.state = .active
             ve.blendingMode = .behindWindow
             ve.alphaValue = 1.0
             ve.layer?.backgroundColor = NSColor.black.withAlphaComponent(0.35).cgColor
+            window.hasShadow = true
+            window.backgroundColor = .clear
         } else {
+            ve.state = .inactive
             ve.blendingMode = .withinWindow
-            ve.alphaValue = 0.0
+            ve.alphaValue = 1.0
             ve.layer?.backgroundColor = NSColor.clear.cgColor
+            ve.isHidden = true
+            window.hasShadow = false
+            // 纯 clear 在部分系统上会产生窗口合成残影；使用极小 alpha 避免 Ghosting。
+            window.backgroundColor = tinyAlphaBackground
         }
+        window.contentView?.layerContentsRedrawPolicy = .onSetNeedsDisplay
+        window.contentView?.needsDisplay = true
+        window.contentView?.displayIfNeeded()
+        hostingView?.layerContentsRedrawPolicy = .onSetNeedsDisplay
+        hostingView?.needsDisplay = true
+        hostingView?.displayIfNeeded()
+        window.invalidateShadow()
         DispatchQueue.main.asyncAfter(deadline: .now() + 0.2) { [weak self] in
             self?.dumpGeometry("backdropEnabled=\(enabled)")
         }
     }
 
+    func refreshAfterDataUpdate() {
+        guard let window = window else { return }
+        window.contentView?.needsDisplay = true
+        hostingView?.needsDisplay = true
+        window.displayIfNeeded()
+        window.invalidateShadow()
+    }
+
     // MARK: - SwiftUI 嵌入
 
     func embed(rootView: ContentView) {
@@ -153,6 +179,7 @@ final class FloatingWindowController: NSWindowController {
 
         let hv = NSHostingView(rootView: rootView)
         hv.wantsLayer = true
+        hv.layerContentsRedrawPolicy = .onSetNeedsDisplay
         hv.layer?.cornerRadius = Configuration.shared.backdropEnabled ? 16 : 0
         hv.layer?.masksToBounds = true
         hv.translatesAutoresizingMaskIntoConstraints = false
diff --git a/Sources/FloatingMonitor/ContentView.swift b/Sources/FloatingMonitor/ContentView.swift
index 90e4975..2cf8a7b 100644
--- a/Sources/FloatingMonitor/ContentView.swift
+++ b/Sources/FloatingMonitor/ContentView.swift
@@ -46,6 +46,9 @@ struct ContentView: View {
                 monitor.interval = interval
             }
         }
+        .onReceive(monitor.$info) { _ in
+            windowController?.refreshAfterDataUpdate()
+        }
     }
 
     // MARK: - 顶部栏（精简版）