Fix Mica readability: links, window border, overlay filter pane

src/UniGetUI.Avalonia/Assets/Styles/Styles.Common.axaml

@@ -18,6 +18,8 @@
                     <SolidColorBrush x:Key="AccentTextFillColorSecondaryBrush" Color="{DynamicResource SystemAccentColorDark3}"/>
                     <SolidColorBrush x:Key="AccentTextFillColorTertiaryBrush"  Color="{DynamicResource SystemAccentColorDark1}"/>
                     <SolidColorBrush x:Key="AccentTextFillColorDisabledBrush"  Color="#5C000000"/>
+                    <!-- Hyperlinks: fixed blue, decoupled from the accent so links stay readable over accent-tinted Mica -->
+                    <SolidColorBrush x:Key="HyperlinkForeground"               Color="#1C5FB8"/>
                     <!-- Text fill -->
                     <SolidColorBrush x:Key="TextFillColorPrimaryBrush"   Color="#E4000000"/>
                     <SolidColorBrush x:Key="TextFillColorSecondaryBrush" Color="#9E000000"/>
@@ -81,6 +83,7 @@
                     <SolidColorBrush x:Key="AccentTextFillColorSecondaryBrush" Color="{DynamicResource SystemAccentColorLight3}"/>
                     <SolidColorBrush x:Key="AccentTextFillColorTertiaryBrush"  Color="{DynamicResource SystemAccentColorLight2}"/>
                     <SolidColorBrush x:Key="AccentTextFillColorDisabledBrush"  Color="#5CFFFFFF"/>
+                    <SolidColorBrush x:Key="HyperlinkForeground"               Color="#A6D4FF"/>
                     <!-- Text fill -->
                     <SolidColorBrush x:Key="TextFillColorPrimaryBrush"   Color="#FFFFFFFF"/>
                     <SolidColorBrush x:Key="TextFillColorSecondaryBrush" Color="#C5FFFFFF"/>

src/UniGetUI.Avalonia/Infrastructure/MicaWindowHelper.cs

@@ -10,19 +10,18 @@ namespace UniGetUI.Avalonia.Infrastructure;
 
 /// <summary>
 /// Gives a standard Avalonia <see cref="Window"/> the native Windows 11 look:
-/// the Mica backdrop (whole-window), rounded corners, and an accent-colored border
-/// that follows focus. Windows-only and gated on Windows 11; a no-op elsewhere, so
+/// the Mica backdrop (whole-window) and rounded corners. The window border is left
+/// at the OS default, so it only shows an accent color if the user enabled that in
+/// Personalization. Windows-only and gated on Windows 11; a no-op elsewhere, so
 /// the window keeps its opaque look when Mica isn't available.
 /// Used by the secondary windows/dialogs; MainWindow has its own (custom-frame) variant.
 /// </summary>
 internal static class MicaWindowHelper
 {
     private const int DWMWA_WINDOW_CORNER_PREFERENCE = 33;
-    private const int DWMWA_BORDER_COLOR = 34;
     private const int DWMWA_SYSTEMBACKDROP_TYPE = 38;
     private const int DWMWCP_ROUND = 2;
     private const int DWMSBT_TRANSIENTWINDOW = 3; // Acrylic — for transient surfaces (menus/flyouts); Mica won't paint on these
-    private const int DWMWA_COLOR_DEFAULT = unchecked((int)0xFFFFFFFF);
 
     private static bool _acrylicPopupsHooked;
 
@@ -44,20 +43,7 @@ public static void Apply(Window window)
                 NativeMethods.DwmSetWindowAttribute(handle, DWMWA_WINDOW_CORNER_PREFERENCE, ref corner, sizeof(int));
             }
             window.Background = Brushes.Transparent;
-            ApplyBorderAccent(window, window.IsActive);
         };
-
-        window.GetObservable(WindowBase.IsActiveProperty).Subscribe(active => ApplyBorderAccent(window, active));
-
-        if (Application.Current?.PlatformSettings is { } settings)
-        {
-            void Handler(object? s, PlatformColorValues e)
-            {
-                if (window.IsActive) ApplyBorderAccent(window, true);
-            }
-            settings.ColorValuesChanged += Handler;
-            window.Closed += (_, _) => settings.ColorValuesChanged -= Handler;
-        }
     }
 
     // Gives flyouts / menus / combo dropdowns / tooltips a native Win11 acrylic backdrop:
@@ -102,22 +88,6 @@ private static void ApplyAcrylicToPopup(TopLevel root)
         NativeMethods.DwmSetWindowAttribute(handle, DWMWA_SYSTEMBACKDROP_TYPE, ref backdrop, sizeof(int));
     }
 
-    // Accent-coloured window border that follows focus (kept on the dialogs).
-    private static void ApplyBorderAccent(Window window, bool active)
-    {
-        if (window.TryGetPlatformHandle()?.Handle is not { } handle || handle == 0)
-            return;
-
-        int colorRef = DWMWA_COLOR_DEFAULT;
-        if (active)
-        {
-            Color accent = Application.Current?.PlatformSettings?.GetColorValues().AccentColor1
-                           ?? Colors.Transparent;
-            colorRef = accent.R | (accent.G << 8) | (accent.B << 16); // Color -> COLORREF (0x00BBGGRR)
-        }
-        NativeMethods.DwmSetWindowAttribute(handle, DWMWA_BORDER_COLOR, ref colorRef, sizeof(int));
-    }
-
     /// <summary>
     /// True when the native Mica look should be used: Windows 11+ AND the user has
     /// "Transparency effects" enabled. When transparency is off we keep the solid look,

src/UniGetUI.Avalonia/Views/DialogPages/PackageDetailsWindow.axaml.cs

@@ -399,9 +399,10 @@ private void AddDownloadRow(StackPanel host)
         host.Children.Add(tb);
     }
 
-    private static IBrush LinkBrush =>
-        Application.Current?.Resources["AccentTextFillColorPrimaryBrush"] as IBrush
-        ?? new SolidColorBrush(Color.FromArgb(255, 0, 120, 212));
+    private IBrush LinkBrush =>
+        this.TryFindResource("HyperlinkForeground", ActualThemeVariant, out var res) && res is IBrush b
+            ? b
+            : new SolidColorBrush(Color.FromArgb(255, 0, 120, 212));
 
     private static void OpenUrl(string url)
     {

src/UniGetUI.Avalonia/Views/SoftwarePages/AbstractPackagesPage.axaml.cs

@@ -24,6 +24,7 @@ public abstract partial class AbstractPackagesPage : UserControl,
     private readonly ContextMenu? _contextMenu;
     private double _savedFilterPaneWidth = 220;
     private bool _isOverlayMode;
+    private IDisposable? _sidePanelBgBinding;
 
     protected AbstractPackagesPage(PackagesPageData data)
     {
@@ -349,16 +350,22 @@ private void UpdateFilterPaneColumn(bool open)
             SidePanel.Width = _savedFilterPaneWidth;
             SidePanel.HorizontalAlignment = HorizontalAlignment.Left;
 
+            // Floating over content needs an opaque surface (the page surface is transparent under Mica).
+            _sidePanelBgBinding ??= SidePanel.Bind(Border.BackgroundProperty, this.GetResourceObservable("AppWindowBackground"));
+
             // Semi-transparent backdrop covers the package list behind the pane.
             FilterOverlayBackdrop.IsVisible = open;
         }
         else
         {
-            // Inline mode: pane sits beside the package list.
+            // Inline mode: pane sits beside the package list and blends with the Mica page surface.
             Grid.SetColumnSpan(SidePanel, 1);
             SidePanel.ZIndex = 0;
             SidePanel.Width = double.NaN;
             SidePanel.HorizontalAlignment = HorizontalAlignment.Stretch;
+            _sidePanelBgBinding?.Dispose();
+            _sidePanelBgBinding = null;
+            SidePanel.Background = null;
             FilterOverlayBackdrop.IsVisible = false;
 
             FilteringPanel.ColumnDefinitions[0].Width = open