diff --git a/clients/apple/macOS/VoiceCatMac/Windows/MainWindowController.swift b/clients/apple/macOS/VoiceCatMac/Windows/MainWindowController.swift
index f8f524d..de5446a 100644
--- a/clients/apple/macOS/VoiceCatMac/Windows/MainWindowController.swift
+++ b/clients/apple/macOS/VoiceCatMac/Windows/MainWindowController.swift
@@ -125,6 +125,7 @@ final class MainWindowController: NSWindowController, NSWindowDelegate {
         let innerSplit = NSSplitView()
         innerSplit.isVertical = false
         innerSplit.dividerStyle = .thin
+        innerSplit.translatesAutoresizingMaskIntoConstraints = false
 
         let channelPanel = buildChannelPanel()
         let userPanel = buildUserPanel()
@@ -137,6 +138,7 @@ final class MainWindowController: NSWindowController, NSWindowDelegate {
         let rightSplit = NSSplitView()
         rightSplit.isVertical = false
         rightSplit.dividerStyle = .thin
+        rightSplit.translatesAutoresizingMaskIntoConstraints = false
         let chatPanel = buildChatPanel()
         let activityPanel = buildActivityPanel()
         rightSplit.addArrangedSubview(chatPanel)
@@ -178,6 +180,17 @@ final class MainWindowController: NSWindowController, NSWindowDelegate {
             composeBar.bottomAnchor.constraint(equalTo: contentView.bottomAnchor),
             composeBar.heightAnchor.constraint(equalToConstant: 36),
         ])
+
+        // Set initial divider positions so panels get reasonable space instead of
+        // collapsing to zero. These are applied after the window is on screen.
+        DispatchQueue.main.async { [weak self, weak outerSplit, weak innerSplit, weak rightSplit] in
+            // outerSplit is vertical (left|right): divide at 40% from left
+            outerSplit?.setPosition(360, ofDividerAt: 0)
+            // innerSplit is horizontal (channels on top, users below): divide at 60% from top
+            innerSplit?.setPosition(260, ofDividerAt: 0)
+            // rightSplit is horizontal (chat on top, activity below): divide at 70% from top
+            rightSplit?.setPosition(280, ofDividerAt: 0)
+        }
     }
 
     private func buildChannelPanel() -> NSView {
@@ -195,6 +208,7 @@ final class MainWindowController: NSWindowController, NSWindowDelegate {
         sv.documentView = channelOutlineView
         sv.hasVerticalScroller = true
         sv.borderType = .noBorder
+        sv.translatesAutoresizingMaskIntoConstraints = false
 
         let menu = NSMenu()
         menu.delegate = self
@@ -221,6 +235,7 @@ final class MainWindowController: NSWindowController, NSWindowDelegate {
         sv.documentView = userTableView
         sv.hasVerticalScroller = true
         sv.borderType = .noBorder
+        sv.translatesAutoresizingMaskIntoConstraints = false
         return sv
     }
 
@@ -233,6 +248,7 @@ final class MainWindowController: NSWindowController, NSWindowDelegate {
         sv.documentView = chatTextView
         sv.hasVerticalScroller = true
         sv.borderType = .noBorder
+        sv.translatesAutoresizingMaskIntoConstraints = false
         return sv
     }
 
@@ -248,6 +264,7 @@ final class MainWindowController: NSWindowController, NSWindowDelegate {
         sv.documentView = activityTableView
         sv.hasVerticalScroller = true
         sv.borderType = .noBorder
+        sv.translatesAutoresizingMaskIntoConstraints = false
         return sv
     }
 
@@ -365,6 +382,8 @@ final class MainWindowController: NSWindowController, NSWindowDelegate {
 
             levelMeter.widthAnchor.constraint(equalToConstant: 100),
             devicePicker.widthAnchor.constraint(greaterThanOrEqualToConstant: 160),
+
+            panel.heightAnchor.constraint(equalToConstant: 96),
         ])
         return panel
     }