diff --git a/src/TeamsISO.App.WinUI/Views/MainWindow.xaml.cs b/src/TeamsISO.App.WinUI/Views/MainWindow.xaml.cs
index a03cca3..22e6443 100644
--- a/src/TeamsISO.App.WinUI/Views/MainWindow.xaml.cs
+++ b/src/TeamsISO.App.WinUI/Views/MainWindow.xaml.cs
@@ -213,22 +213,35 @@ public sealed partial class MainWindow : Window
     }
 
     /// <summary>
-    /// Minimal participant row — name + ISO state + toggle button. Drops
-    /// the brushed avatar / theme-resource lookups that may have been
-    /// triggering the crash. The full visual row template comes back
-    /// after we've verified the binding path works.
+    /// Participant row — name + ISO state pill, with the cyan-accent
+    /// left border when the participant is the active speaker, and the
+    /// pill background flipping green/coral/amber based on ISO state.
+    /// Imperative construction so we sidestep the WinUI 3 DataTemplate
+    /// parser path that crashes on this build host.
     /// </summary>
     private static Microsoft.UI.Xaml.Controls.Grid BuildSimpleRow(ParticipantViewModel p)
     {
         var grid = new Microsoft.UI.Xaml.Controls.Grid
         {
             Height = 56,
-            Padding = new Thickness(20, 0, 20, 0),
+            Padding = new Thickness(0, 0, 20, 0),
         };
+        grid.ColumnDefinitions.Add(new Microsoft.UI.Xaml.Controls.ColumnDefinition { Width = new Microsoft.UI.Xaml.GridLength(3) });
+        grid.ColumnDefinitions.Add(new Microsoft.UI.Xaml.Controls.ColumnDefinition { Width = new Microsoft.UI.Xaml.GridLength(20) });
         grid.ColumnDefinitions.Add(new Microsoft.UI.Xaml.Controls.ColumnDefinition { Width = new Microsoft.UI.Xaml.GridLength(1, Microsoft.UI.Xaml.GridUnitType.Star) });
-        grid.ColumnDefinitions.Add(new Microsoft.UI.Xaml.Controls.ColumnDefinition { Width = new Microsoft.UI.Xaml.GridLength(120) });
+        grid.ColumnDefinitions.Add(new Microsoft.UI.Xaml.Controls.ColumnDefinition { Width = new Microsoft.UI.Xaml.GridLength(140) });
         grid.ColumnDefinitions.Add(new Microsoft.UI.Xaml.Controls.ColumnDefinition { Width = Microsoft.UI.Xaml.GridLength.Auto });
 
+        // Active-speaker left accent. Visible only when IsActiveSpeaker
+        // flips on (driven by MainViewModel.OnStatsTick at 1Hz).
+        var accent = new Microsoft.UI.Xaml.Controls.Border
+        {
+            Background = (Microsoft.UI.Xaml.Media.Brush)Application.Current.Resources["AccentCyanText"],
+            Visibility = p.IsActiveSpeaker ? Visibility.Visible : Visibility.Collapsed,
+        };
+        Microsoft.UI.Xaml.Controls.Grid.SetColumn(accent, 0);
+        grid.Children.Add(accent);
+
         var nameStack = new Microsoft.UI.Xaml.Controls.StackPanel
         {
             VerticalAlignment = VerticalAlignment.Center,
@@ -248,7 +261,7 @@ public sealed partial class MainWindow : Window
         };
         nameStack.Children.Add(nameText);
         nameStack.Children.Add(codecText);
-        Microsoft.UI.Xaml.Controls.Grid.SetColumn(nameStack, 0);
+        Microsoft.UI.Xaml.Controls.Grid.SetColumn(nameStack, 2);
         grid.Children.Add(nameStack);
 
         var outputText = new Microsoft.UI.Xaml.Controls.TextBlock
@@ -258,7 +271,7 @@ public sealed partial class MainWindow : Window
             FontSize = 12,
             VerticalAlignment = VerticalAlignment.Center,
         };
-        Microsoft.UI.Xaml.Controls.Grid.SetColumn(outputText, 1);
+        Microsoft.UI.Xaml.Controls.Grid.SetColumn(outputText, 3);
         grid.Children.Add(outputText);
 
         var pillText = new Microsoft.UI.Xaml.Controls.TextBlock
@@ -277,7 +290,8 @@ public sealed partial class MainWindow : Window
             VerticalAlignment = VerticalAlignment.Center,
             Content = pillText,
         };
-        Microsoft.UI.Xaml.Controls.Grid.SetColumn(pill, 2);
+        ApplyIsoPillStyling(pill, pillText, p.IsoStateLabel);
+        Microsoft.UI.Xaml.Controls.Grid.SetColumn(pill, 4);
         grid.Children.Add(pill);
 
         p.PropertyChanged += (_, e) =>
@@ -298,6 +312,12 @@ public sealed partial class MainWindow : Window
                     case nameof(ParticipantViewModel.IsoStateLabel):
                     case nameof(ParticipantViewModel.IsEnabled):
                         pillText.Text = p.IsoStateLabel;
+                        ApplyIsoPillStyling(pill, pillText, p.IsoStateLabel);
+                        break;
+                    case nameof(ParticipantViewModel.IsActiveSpeaker):
+                        accent.Visibility = p.IsActiveSpeaker
+                            ? Visibility.Visible
+                            : Visibility.Collapsed;
                         break;
                 }
             });
@@ -306,6 +326,49 @@ public sealed partial class MainWindow : Window
         return grid;
     }
 
+    /// <summary>
+    /// Re-color the ISO pill based on the engine's reported state.
+    /// LIVE = green on green-tinted background. ERROR = coral on coral-
+    /// tinted background. STARTING = amber. NO SIGNAL = amber. OFF =
+    /// neutral surface. Mirrors the WPF host's IsoToggle data-trigger
+    /// behavior but built imperatively from theme-resource brush keys.
+    /// </summary>
+    private static void ApplyIsoPillStyling(
+        Microsoft.UI.Xaml.Controls.Button pill,
+        Microsoft.UI.Xaml.Controls.TextBlock pillText,
+        string state)
+    {
+        Microsoft.UI.Xaml.Media.Brush bg, border, fg;
+        switch (state)
+        {
+            case "LIVE":
+                bg = (Microsoft.UI.Xaml.Media.Brush)Application.Current.Resources["StatusLiveBg"];
+                border = (Microsoft.UI.Xaml.Media.Brush)Application.Current.Resources["StatusLive"];
+                fg = (Microsoft.UI.Xaml.Media.Brush)Application.Current.Resources["StatusLive"];
+                break;
+            case "ERROR":
+                bg = (Microsoft.UI.Xaml.Media.Brush)Application.Current.Resources["AccentCoralBg"];
+                border = (Microsoft.UI.Xaml.Media.Brush)Application.Current.Resources["AccentCoral"];
+                fg = (Microsoft.UI.Xaml.Media.Brush)Application.Current.Resources["AccentCoral"];
+                break;
+            case "NO SIGNAL":
+            case "STARTING":
+                bg = (Microsoft.UI.Xaml.Media.Brush)Application.Current.Resources["StatusWarnBg"];
+                border = (Microsoft.UI.Xaml.Media.Brush)Application.Current.Resources["StatusWarn"];
+                fg = (Microsoft.UI.Xaml.Media.Brush)Application.Current.Resources["StatusWarn"];
+                break;
+            default: // OFF / —
+                bg = (Microsoft.UI.Xaml.Media.Brush)Application.Current.Resources["BgSurface"];
+                border = (Microsoft.UI.Xaml.Media.Brush)Application.Current.Resources["BorderStrong"];
+                fg = (Microsoft.UI.Xaml.Media.Brush)Application.Current.Resources["FgPrimary"];
+                break;
+        }
+        pill.Background = bg;
+        pill.BorderBrush = border;
+        pill.BorderThickness = new Thickness(1);
+        pillText.Foreground = fg;
+    }
+
     /// <summary>Full rich row template — replaces BuildSimpleRow once we've verified the simple version doesn't crash.</summary>
     private static Microsoft.UI.Xaml.Controls.Grid BuildParticipantRow(ParticipantViewModel p)
     {