WPF layout (#3346)

2021-02-21 12:38:56 +01:00
parent 33d6975c25
commit b898443f28
121 changed files with 1420 additions and 2069 deletions
--- a/Content.Client/UserInterface/ActionMenu.cs
+++ b/Content.Client/UserInterface/ActionMenu.cs
@@ -68,7 +68,7 @@ namespace Content.Client.UserInterface
            _gameHud = IoCManager.Resolve<IGameHud>();

            Title = Loc.GetString("Actions");
-            CustomMinimumSize = (300, 300);
+            MinSize = (300, 300);

            Contents.AddChild(new VBoxContainer
            {
@@ -81,7 +81,7 @@ namespace Content.Client.UserInterface
                            (_searchBar = new LineEdit
                            {
                                StyleClasses = { StyleNano.StyleClassActionSearchBox },
-                                SizeFlagsHorizontal = SizeFlags.FillExpand,
+                                HorizontalExpand = true,
                                PlaceHolder = Loc.GetString("Search")
                            }),
                            (_filterButton = new MultiselectOptionButton<string>()
@@ -97,14 +97,14 @@ namespace Content.Client.UserInterface
                    (_filterLabel = new Label()),
                    new ScrollContainer
                    {
-                        //TODO: needed? CustomMinimumSize = new Vector2(200.0f, 0.0f),
-                        SizeFlagsVertical = SizeFlags.FillExpand,
-                        SizeFlagsHorizontal = SizeFlags.FillExpand,
+                        //TODO: needed? MinSize = new Vector2(200.0f, 0.0f),
+                        VerticalExpand = true,
+                        HorizontalExpand = true,
                        Children =
                        {
                            (_resultsGrid = new GridContainer
                            {
-                                MaxWidth = 300
+                                MaxGridWidth = 300
                            })
                        }
                    }
@@ -136,12 +136,12 @@ namespace Content.Client.UserInterface

            _dragShadow = new TextureRect
            {
-                CustomMinimumSize = (64, 64),
+                MinSize = (64, 64),
                Stretch = TextureRect.StretchMode.Scale,
-                Visible = false
+                Visible = false,
+                SetSize = (64, 64)
            };
            UserInterfaceManager.PopupRoot.AddChild(_dragShadow);
-            LayoutContainer.SetSize(_dragShadow, (64, 64));

            _dragDropHelper = new DragDropHelper<ActionMenuItem>(OnBeginActionDrag, OnContinueActionDrag, OnEndActionDrag);
        }
@@ -190,7 +190,7 @@ namespace Content.Client.UserInterface
            base.Resized();
            // TODO: Can rework this once https://github.com/space-wizards/RobustToolbox/issues/1392 is done,
            // currently no good way to let the grid know what size it has to "work with", so must manually resize
-            _resultsGrid.MaxWidth = Width;
+            _resultsGrid.MaxGridWidth = Width;
        }

        private bool OnBeginActionDrag()
--- a/Content.Client/UserInterface/ActionMenuItem.cs
+++ b/Content.Client/UserInterface/ActionMenuItem.cs
@@ -27,13 +27,13 @@ namespace Content.Client.UserInterface
            _onControlFocusExited = onControlFocusExited;
            Action = action;

-            CustomMinimumSize = (64, 64);
-            SizeFlagsVertical = SizeFlags.None;
+            MinSize = (64, 64);
+            VerticalAlignment = VAlignment.Top;

            AddChild(new TextureRect
            {
-                SizeFlagsHorizontal = SizeFlags.FillExpand,
-                SizeFlagsVertical = SizeFlags.FillExpand,
+                HorizontalExpand = true,
+                VerticalExpand = true,
                Stretch = TextureRect.StretchMode.Scale,
                Texture = action.Icon.Frame0()
            });
--- a/Content.Client/UserInterface/ActionsUI.cs
+++ b/Content.Client/UserInterface/ActionsUI.cs
@@ -16,7 +16,6 @@ using Robust.Shared.Input;
 using Robust.Shared.Input.Binding;
 using Robust.Shared.IoC;
 using Robust.Shared.Log;
-using Robust.Shared.Maths;
 using Robust.Shared.Timing;

 namespace Content.Client.UserInterface
@@ -75,6 +74,7 @@ namespace Content.Client.UserInterface

        public ActionsUI(ClientActionsComponent actionsComponent)
        {
+            SetValue(LayoutContainer.DebugProperty, true);
            _actionsComponent = actionsComponent;
            _actionManager = IoCManager.Resolve<ActionManager>();
            _entityManager = IoCManager.Resolve<IEntityManager>();
@@ -83,14 +83,14 @@ namespace Content.Client.UserInterface
            _menu = new ActionMenu(_actionsComponent, this);

            LayoutContainer.SetGrowHorizontal(this, LayoutContainer.GrowDirection.End);
-            LayoutContainer.SetGrowVertical(this, LayoutContainer.GrowDirection.End);
+            LayoutContainer.SetGrowVertical(this, LayoutContainer.GrowDirection.Constrain);
            LayoutContainer.SetAnchorTop(this, 0f);
            LayoutContainer.SetAnchorBottom(this, 0.8f);
            LayoutContainer.SetMarginLeft(this, 13);
            LayoutContainer.SetMarginTop(this, 110);

-            SizeFlagsHorizontal = SizeFlags.None;
-            SizeFlagsVertical = SizeFlags.FillExpand;
+            HorizontalAlignment = HAlignment.Left;
+            VerticalExpand = true;

            var resourceCache = IoCManager.Resolve<IResourceCache>();

@@ -101,101 +101,101 @@ namespace Content.Client.UserInterface
            var panelContainer = new PanelContainer()
            {
                StyleClasses = {StyleNano.StyleClassHotbarPanel},
-                SizeFlagsHorizontal = SizeFlags.None,
-                SizeFlagsVertical = SizeFlags.None
+                HorizontalAlignment = HAlignment.Left,
+                VerticalAlignment = VAlignment.Top
            };
            AddChild(panelContainer);

            var hotbarContainer = new VBoxContainer
            {
                SeparationOverride = 3,
-                SizeFlagsHorizontal = SizeFlags.None
+                HorizontalAlignment = HAlignment.Left
            };
            panelContainer.AddChild(hotbarContainer);

            var settingsContainer = new HBoxContainer
            {
-                SizeFlagsHorizontal = SizeFlags.FillExpand
+                HorizontalExpand = true
            };
            hotbarContainer.AddChild(settingsContainer);

-            settingsContainer.AddChild(new Control { SizeFlagsHorizontal = SizeFlags.FillExpand, SizeFlagsStretchRatio = 1 });
+            settingsContainer.AddChild(new Control { HorizontalExpand = true, SizeFlagsStretchRatio = 1 });
            _lockTexture = resourceCache.GetTexture("/Textures/Interface/Nano/lock.svg.192dpi.png");
            _unlockTexture = resourceCache.GetTexture("/Textures/Interface/Nano/lock_open.svg.192dpi.png");
            _lockButton = new TextureButton
            {
                TextureNormal = _unlockTexture,
-                SizeFlagsHorizontal = SizeFlags.ShrinkCenter,
-                SizeFlagsVertical = SizeFlags.ShrinkCenter,
+                HorizontalAlignment = HAlignment.Center,
+                VerticalAlignment = VAlignment.Center,
                SizeFlagsStretchRatio = 1,
                Scale = (0.5f, 0.5f)
            };
            settingsContainer.AddChild(_lockButton);
-            settingsContainer.AddChild(new Control { SizeFlagsHorizontal = SizeFlags.FillExpand, SizeFlagsStretchRatio = 2 });
+            settingsContainer.AddChild(new Control { HorizontalExpand = true, SizeFlagsStretchRatio = 2 });
            _settingsButton = new TextureButton
            {
                TextureNormal = resourceCache.GetTexture("/Textures/Interface/Nano/gear.svg.192dpi.png"),
-                SizeFlagsHorizontal = SizeFlags.ShrinkCenter,
-                SizeFlagsVertical = SizeFlags.ShrinkCenter,
+                HorizontalAlignment = HAlignment.Center,
+                VerticalAlignment = VAlignment.Center,
                SizeFlagsStretchRatio = 1,
                Scale = (0.5f, 0.5f)
            };
            settingsContainer.AddChild(_settingsButton);
-            settingsContainer.AddChild(new Control { SizeFlagsHorizontal = SizeFlags.FillExpand, SizeFlagsStretchRatio = 1 });
+            settingsContainer.AddChild(new Control { HorizontalExpand = true, SizeFlagsStretchRatio = 1 });

            // this allows a 2 column layout if window gets too small
            _slotContainer = new GridContainer
            {
-                MaxHeight = CalcMaxHeight()
+                MaxGridHeight = CalcMaxHeight()
            };
            hotbarContainer.AddChild(_slotContainer);

            _loadoutContainer = new HBoxContainer
            {
-                SizeFlagsHorizontal = SizeFlags.FillExpand,
+                HorizontalExpand = true,
                MouseFilter = MouseFilterMode.Stop
            };
            hotbarContainer.AddChild(_loadoutContainer);

-            _loadoutContainer.AddChild(new Control { SizeFlagsHorizontal = SizeFlags.FillExpand, SizeFlagsStretchRatio = 1 });
+            _loadoutContainer.AddChild(new Control { HorizontalExpand = true, SizeFlagsStretchRatio = 1 });
            var previousHotbarIcon = new TextureRect()
            {
                Texture = resourceCache.GetTexture("/Textures/Interface/Nano/left_arrow.svg.192dpi.png"),
-                SizeFlagsHorizontal = SizeFlags.ShrinkCenter,
-                SizeFlagsVertical = SizeFlags.ShrinkCenter,
+                HorizontalAlignment = HAlignment.Center,
+                VerticalAlignment = VAlignment.Center,
                SizeFlagsStretchRatio = 1,
                TextureScale = (0.5f, 0.5f)
            };
            _loadoutContainer.AddChild(previousHotbarIcon);
-            _loadoutContainer.AddChild(new Control { SizeFlagsHorizontal = SizeFlags.FillExpand, SizeFlagsStretchRatio = 2 });
+            _loadoutContainer.AddChild(new Control { HorizontalExpand = true, SizeFlagsStretchRatio = 2 });
            _loadoutNumber = new Label
            {
                Text = "1",
                SizeFlagsStretchRatio = 1
            };
            _loadoutContainer.AddChild(_loadoutNumber);
-            _loadoutContainer.AddChild(new Control { SizeFlagsHorizontal = SizeFlags.FillExpand, SizeFlagsStretchRatio = 2 });
+            _loadoutContainer.AddChild(new Control { HorizontalExpand = true, SizeFlagsStretchRatio = 2 });
            var nextHotbarIcon = new TextureRect
            {
                Texture = resourceCache.GetTexture("/Textures/Interface/Nano/right_arrow.svg.192dpi.png"),
-                SizeFlagsHorizontal = SizeFlags.ShrinkCenter,
-                SizeFlagsVertical = SizeFlags.ShrinkCenter,
+                HorizontalAlignment = HAlignment.Center,
+                VerticalAlignment = VAlignment.Center,
                SizeFlagsStretchRatio = 1,
                TextureScale = (0.5f, 0.5f)
            };
            _loadoutContainer.AddChild(nextHotbarIcon);
-            _loadoutContainer.AddChild(new Control { SizeFlagsHorizontal = SizeFlags.FillExpand, SizeFlagsStretchRatio = 1 });
+            _loadoutContainer.AddChild(new Control { HorizontalExpand = true, SizeFlagsStretchRatio = 1 });

            _slots = new ActionSlot[ClientActionsComponent.Slots];

            _dragShadow = new TextureRect
            {
-                CustomMinimumSize = (64, 64),
+                MinSize = (64, 64),
                Stretch = TextureRect.StretchMode.Scale,
-                Visible = false
+                Visible = false,
+                SetSize = (64, 64)
            };
            UserInterfaceManager.PopupRoot.AddChild(_dragShadow);
-            LayoutContainer.SetSize(_dragShadow, (64, 64));

            for (byte i = 0; i < ClientActionsComponent.Slots; i++)
            {
@@ -205,6 +205,8 @@ namespace Content.Client.UserInterface
            }

            DragDropHelper = new DragDropHelper<ActionSlot>(OnBeginActionDrag, OnContinueActionDrag, OnEndActionDrag);
+
+            MinSize = (10, 400);
        }

        protected override void EnteredTree()
@@ -231,16 +233,10 @@ namespace Content.Client.UserInterface
            _gameHud.ActionsButtonVisible = false;
        }

-        protected override Vector2 CalculateMinimumSize()
-        {
-            // allows us to shrink down to a 2-column layout minimum
-            return (10, 400);
-        }
-
        protected override void Resized()
        {
            base.Resized();
-            _slotContainer.MaxHeight = CalcMaxHeight();
+            _slotContainer.MaxGridHeight = CalcMaxHeight();
        }

        private float CalcMaxHeight()
@@ -265,7 +261,7 @@ namespace Content.Client.UserInterface

        protected override void UIScaleChanged()
        {
-            _slotContainer.MaxHeight = CalcMaxHeight();
+            _slotContainer.MaxGridHeight = CalcMaxHeight();
            base.UIScaleChanged();
        }

--- a/Content.Client/UserInterface/AdminAddReagentUI.cs
+++ b/Content.Client/UserInterface/AdminAddReagentUI.cs
@@ -82,11 +82,11 @@ namespace Content.Client.UserInterface
                                (_amountEdit = new LineEdit
                                {
                                    PlaceHolder = Loc.GetString("A number..."),
-                                    SizeFlagsHorizontal = SizeFlags.FillExpand
+                                    HorizontalExpand = true
                                }),
                            },
-                            SizeFlagsHorizontal = SizeFlags.FillExpand,
-                            SizeFlagsVertical = SizeFlags.FillExpand
+                            HorizontalExpand = true,
+                            VerticalExpand = true
                        },
                        new HBoxContainer
                        {
@@ -94,7 +94,7 @@ namespace Content.Client.UserInterface
                            {
                                (_errorLabel = new Label
                                {
-                                    SizeFlagsHorizontal = SizeFlags.FillExpand,
+                                    HorizontalExpand = true,
                                    ClipText = true
                                }),

--- a/Content.Client/UserInterface/AdminMenu/AdminMenuWindow.xaml.cs
+++ b/Content.Client/UserInterface/AdminMenu/AdminMenuWindow.xaml.cs
@@ -21,10 +21,9 @@ namespace Content.Client.UserInterface.AdminMenu
            remove => PlayerTabControl.OnPlayerListRefresh -= value;
        }

-        protected override Vector2? CustomSize => (500, 250);
-
        public AdminMenuWindow()
        {
+            MinSize = SetSize = (500, 250);
            Title = Loc.GetString("Admin Menu");
            RobustXamlLoader.Load(this);
            IoCManager.InjectDependencies(this);
--- a/Content.Client/UserInterface/AdminMenu/SetOutfit/SetOutfitMenu.xaml
+++ b/Content.Client/UserInterface/AdminMenu/SetOutfit/SetOutfitMenu.xaml
@@ -1,15 +1,15 @@
 <SS14Window
    xmlns="https://spacestation14.io">
-    <HBoxContainer SizeFlagsHorizontal="FillExpand">
-        <VBoxContainer SizeFlagsHorizontal="FillExpand" SizeFlagsStretchRatio="0.45">
-            <HBoxContainer SizeFlagsHorizontal="FillExpand" SizeFlagsVertical="FillExpand"
+    <HBoxContainer HorizontalExpand="True">
+        <VBoxContainer HorizontalExpand="True" SizeFlagsStretchRatio="0.45">
+            <HBoxContainer HorizontalExpand="True" VerticalExpand="True"
                                    SizeFlagsStretchRatio="0.1">
-                <LineEdit Name="SearchBar" PlaceHolder="Search" SizeFlagsHorizontal="FillExpand"
+                <LineEdit Name="SearchBar" PlaceHolder="Search" HorizontalExpand="True"
                                   SizeFlagsStretchRatio="0.6" />
            </HBoxContainer>
-            <ItemList Name="OutfitList" SelectMode="Single" SizeFlagsVertical="FillExpand"
+            <ItemList Name="OutfitList" SelectMode="Single" VerticalExpand="True"
                               SizeFlagsStretchRatio="0.9" />
-            <Button Name="ConfirmButton" SizeFlagsHorizontal="FillExpand" />
+            <Button Name="ConfirmButton" HorizontalExpand="True" />
        </VBoxContainer>
    </HBoxContainer>
 </SS14Window>
--- a/Content.Client/UserInterface/AdminMenu/SetOutfit/SetOutfitMenu.xaml.cs
+++ b/Content.Client/UserInterface/AdminMenu/SetOutfit/SetOutfitMenu.xaml.cs
@@ -20,12 +20,11 @@ namespace Content.Client.UserInterface.AdminMenu.SetOutfit
        [Dependency] private readonly IClientConsoleHost _consoleHost = default!;

        public EntityUid? TargetEntityId { get; set; }
-        protected override Vector2? CustomSize => (250, 320);
-
        private StartingGearPrototype? _selectedOutfit;

        public SetOutfitMenu()
        {
+            MinSize = SetSize = (250, 320);
            IoCManager.InjectDependencies(this);
            RobustXamlLoader.Load(this);

--- a/Content.Client/UserInterface/AdminMenu/Tabs/AdminTab/AdminTab.xaml
+++ b/Content.Client/UserInterface/AdminMenu/Tabs/AdminTab/AdminTab.xaml
@@ -1,12 +1,10 @@
-<MarginContainer
+<Control
    xmlns="https://spacestation14.io"
    xmlns:amc="clr-namespace:Content.Client.UserInterface.AdminMenu.CustomControls"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:at="clr-namespace:Content.Client.UserInterface.AdminMenu.Tabs.AdminTab"
-    MarginLeftOverride="4"
-    MarginTopOverride="4" MarginRightOverride="4"
-    MarginBottomOverride="4"
-    CustomMinimumSize="50 50">
+    Margin="4"
+    MinSize="50 50">
    <VBoxContainer>
        <GridContainer Columns="4">
            <amc:UICommandButton Command="kick" Text="{Loc Kick}" WindowType="{x:Type at:KickWindow}" />
@@ -16,4 +14,4 @@
            <amc:CommandButton Command="permissions" Text="{Loc Permissions Panel}" />
        </GridContainer>
    </VBoxContainer>
-</MarginContainer>
+</Control>
--- a/Content.Client/UserInterface/AdminMenu/Tabs/AdminTab/AdminTab.xaml.cs
+++ b/Content.Client/UserInterface/AdminMenu/Tabs/AdminTab/AdminTab.xaml.cs
@@ -1,11 +1,11 @@
 #nullable enable
 using Robust.Client.AutoGenerated;
-using Robust.Client.UserInterface.Controls;
+using Robust.Client.UserInterface;

 namespace Content.Client.UserInterface.AdminMenu.Tabs.AdminTab
 {
    [GenerateTypedNameReferences]
-    public partial class AdminTab : MarginContainer
+    public partial class AdminTab : Control
    {
    }
 }
--- a/Content.Client/UserInterface/AdminMenu/Tabs/AdminTab/BanWindow.xaml
+++ b/Content.Client/UserInterface/AdminMenu/Tabs/AdminTab/BanWindow.xaml
@@ -1,24 +1,24 @@
 <SS14Window
    xmlns="https://spacestation14.io"
    xmlns:cc="clr-namespace:Content.Client.UserInterface.AdminMenu.CustomControls"
-    Title="{Loc Ban}" CustomMinimumSize="425 162">
+    Title="{Loc Ban}" MinSize="425 162">
    <VBoxContainer>
        <HBoxContainer>
-            <Label Text="{Loc Player}" CustomMinimumSize="100 0" />
-            <Control CustomMinimumSize="50 0" />
-            <LineEdit Name="PlayerNameLine" CustomMinimumSize="100 0" SizeFlagsHorizontal="FillExpand" />
+            <Label Text="{Loc Player}" MinWidth="100" />
+            <Control MinWidth="50" />
+            <LineEdit Name="PlayerNameLine" MinWidth="100" HorizontalExpand="True" />
        </HBoxContainer>
        <HBoxContainer>
-            <Label Text="{Loc Reason}" CustomMinimumSize="100 0" />
-            <Control CustomMinimumSize="50 0" />
-            <LineEdit Name="ReasonLine" CustomMinimumSize="100 0" SizeFlagsHorizontal="FillExpand" />
+            <Label Text="{Loc Reason}" MinSize="100 0" />
+            <Control MinSize="50 0" />
+            <LineEdit Name="ReasonLine" MinSize="100 0" HorizontalExpand="True" />
        </HBoxContainer>
        <HBoxContainer>
-            <Label Text="{Loc Minutes}" CustomMinimumSize="100 0" />
-            <Control CustomMinimumSize="50 0" />
-            <LineEdit Name="MinutesLine" CustomMinimumSize="100 0" SizeFlagsHorizontal="FillExpand" PlaceHolder="{Loc 0 minutes for a permanent ban}" />
+            <Label Text="{Loc Minutes}" MinWidth="100" />
+            <Control MinWidth="50" />
+            <LineEdit Name="MinutesLine" MinWidth="100" HorizontalExpand="True" PlaceHolder="{Loc 0 minutes for a permanent ban}" />
        </HBoxContainer>
-        <Control CustomMinimumSize="50 0" />
+        <Control MinWidth="50" />
        <Button Name="SubmitButton" Text="{Loc Ban}" />
    </VBoxContainer>
 </SS14Window>
--- a/Content.Client/UserInterface/AdminMenu/Tabs/AdminTab/KickWindow.xaml
+++ b/Content.Client/UserInterface/AdminMenu/Tabs/AdminTab/KickWindow.xaml
@@ -1,12 +1,12 @@
 <SS14Window
    xmlns="https://spacestation14.io"
    xmlns:cc="clr-namespace:Content.Client.UserInterface.AdminMenu.CustomControls"
-    Title="{Loc Kick}" CustomMinimumSize="425 272">
+    Title="{Loc Kick}" MinSize="425 272">
    <VBoxContainer>
        <HBoxContainer>
-            <Label Text="{Loc Reason}" CustomMinimumSize="100 0" />
-            <Control CustomMinimumSize="50 0" />
-            <LineEdit Name="ReasonLine" CustomMinimumSize="100 0" SizeFlagsHorizontal="FillExpand" />
+            <Label Text="{Loc Reason}" MinWidth="100" />
+            <Control MinWidth="50" />
+            <LineEdit Name="ReasonLine" MinWidth="100" HorizontalExpand="True" />
        </HBoxContainer>
        <cc:PlayerListControl Name="PlayerList" />
        <Button Name="SubmitButton" Text="{Loc Kick}" />
--- a/Content.Client/UserInterface/AdminMenu/Tabs/AdminTab/TeleportWindow.xaml
+++ b/Content.Client/UserInterface/AdminMenu/Tabs/AdminTab/TeleportWindow.xaml
@@ -1,8 +1,8 @@
 <SS14Window
    xmlns="https://spacestation14.io"
    xmlns:cc="clr-namespace:Content.Client.UserInterface.AdminMenu.CustomControls"
-    Title="{Loc Teleport}" CustomMinimumSize="425 230">
-    <VBoxContainer SizeFlagsVertical="FillExpand">
+    Title="{Loc Teleport}" MinSize="425 230">
+    <VBoxContainer>
        <cc:PlayerListControl Name="PlayerList" />
        <Button Name="SubmitButton" Text="{Loc Teleport}" />
    </VBoxContainer>
--- a/Content.Client/UserInterface/AdminMenu/Tabs/AdminbusTab/AdminbusTab.xaml
+++ b/Content.Client/UserInterface/AdminMenu/Tabs/AdminbusTab/AdminbusTab.xaml
@@ -1,16 +1,14 @@
-<MarginContainer
+<Control
    xmlns="https://spacestation14.io"
    xmlns:amc="clr-namespace:Content.Client.UserInterface.AdminMenu.CustomControls"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:abt="clr-namespace:Content.Client.UserInterface.AdminMenu.Tabs.AdminbusTab"
-    MarginLeftOverride="4"
-    MarginTopOverride="4" MarginRightOverride="4"
-    MarginBottomOverride="4"
-    CustomMinimumSize="50 50">
+    Margin="4"
+    MinSize="50 50">
    <GridContainer
        Columns="4">
        <amc:CommandButton Name="SpawnEntitiesButton" Text="{Loc Spawn Entities}" />
        <amc:CommandButton Name="SpawnTilesButton" Text="{Loc Spawn Tiles} " />
        <amc:UICommandButton Command="events" Text="{Loc Station Events}" WindowType="{x:Type abt:StationEventsWindow}" />
    </GridContainer>
-</MarginContainer>
+</Control>
--- a/Content.Client/UserInterface/AdminMenu/Tabs/AdminbusTab/AdminbusTab.xaml.cs
+++ b/Content.Client/UserInterface/AdminMenu/Tabs/AdminbusTab/AdminbusTab.xaml.cs
@@ -2,6 +2,7 @@
 using Robust.Client.AutoGenerated;
 using Robust.Client.Placement;
 using Robust.Client.ResourceManagement;
+using Robust.Client.UserInterface;
 using Robust.Client.UserInterface.Controls;
 using Robust.Client.UserInterface.CustomControls;
 using Robust.Shared.IoC;
@@ -11,7 +12,7 @@ using Robust.Shared.Prototypes;
 namespace Content.Client.UserInterface.AdminMenu.Tabs.AdminbusTab
 {
    [GenerateTypedNameReferences]
-    public partial class AdminbusTab : MarginContainer
+    public partial class AdminbusTab : Control
    {
        protected override void EnteredTree()
        {
--- a/Content.Client/UserInterface/AdminMenu/Tabs/AdminbusTab/StationEventsWindow.xaml
+++ b/Content.Client/UserInterface/AdminMenu/Tabs/AdminbusTab/StationEventsWindow.xaml
@@ -2,9 +2,9 @@
    xmlns="https://spacestation14.io" Title="Kick">
    <VBoxContainer>
        <HBoxContainer>
-            <Label Text="{Loc Event}" CustomMinimumSize="100 0" />
-            <Control CustomMinimumSize="50 0" />
-            <OptionButton Name="EventsOptions" CustomMinimumSize="100 0" SizeFlagsHorizontal="FillExpand" />
+            <Label Text="{Loc Event}" MinSize="100 0" />
+            <Control MinSize="50 0" />
+            <OptionButton Name="EventsOptions" MinSize="100 0" HorizontalExpand="True" />
        </HBoxContainer>
        <Button Name="PauseButton" Text="{Loc Pause}" />
        <Button Name="ResumeButton" Text="{Loc Resume}" />
--- a/Content.Client/UserInterface/AdminMenu/Tabs/AtmosTab/AddAtmosWindow.xaml
+++ b/Content.Client/UserInterface/AdminMenu/Tabs/AtmosTab/AddAtmosWindow.xaml
@@ -2,9 +2,9 @@
    xmlns="https://spacestation14.io" Title="{Loc Add Atmos}">
    <VBoxContainer>
        <HBoxContainer>
-            <Label Text="{Loc Grid}" CustomMinimumSize="100 0" />
-            <Control CustomMinimumSize="50 0" />
-            <OptionButton Name="GridOptions" CustomMinimumSize="100 0" SizeFlagsHorizontal="FillExpand" />
+            <Label Text="{Loc Grid}" MinSize="100 0" />
+            <Control MinSize="50 0" />
+            <OptionButton Name="GridOptions" MinSize="100 0" HorizontalExpand="True" />
        </HBoxContainer>
        <Button Name="SubmitButton" Text="{Loc Add Atmos}" />
    </VBoxContainer>
--- a/Content.Client/UserInterface/AdminMenu/Tabs/AtmosTab/AddGasWindow.xaml
+++ b/Content.Client/UserInterface/AdminMenu/Tabs/AtmosTab/AddGasWindow.xaml
@@ -2,29 +2,29 @@
    xmlns="https://spacestation14.io" Title="{Loc Add Gas}">
    <VBoxContainer>
        <HBoxContainer>
-            <Label Text="{Loc Grid}" CustomMinimumSize="100 0" />
-            <Control CustomMinimumSize="50 0" />
-            <OptionButton Name="GridOptions" CustomMinimumSize="100 0" SizeFlagsHorizontal="FillExpand" />
+            <Label Text="{Loc Grid}" MinSize="100 0" />
+            <Control MinSize="50 0" />
+            <OptionButton Name="GridOptions" MinSize="100 0" HorizontalExpand="True" />
        </HBoxContainer>
        <HBoxContainer>
-            <Label Text="{Loc TileX}" CustomMinimumSize="100 0" />
-            <Control CustomMinimumSize="50 0" />
-            <SpinBox Name="TileXSpin" CustomMinimumSize="100 0" SizeFlagsHorizontal="FillExpand" />
+            <Label Text="{Loc TileX}" MinSize="100 0" />
+            <Control MinSize="50 0" />
+            <SpinBox Name="TileXSpin" MinSize="100 0" HorizontalExpand="True" />
        </HBoxContainer>
        <HBoxContainer>
-            <Label Text="{Loc TileY}" CustomMinimumSize="100 0" />
-            <Control CustomMinimumSize="50 0" />
-            <SpinBox Name="TileYSpin" CustomMinimumSize="100 0" SizeFlagsHorizontal="FillExpand" />
+            <Label Text="{Loc TileY}" MinSize="100 0" />
+            <Control MinSize="50 0" />
+            <SpinBox Name="TileYSpin" MinSize="100 0" HorizontalExpand="True" />
        </HBoxContainer>
        <HBoxContainer>
-            <Label Text="{Loc Gas}" CustomMinimumSize="100 0" />
-            <Control CustomMinimumSize="50 0" />
-            <OptionButton Name="GasOptions" CustomMinimumSize="100 0" SizeFlagsHorizontal="FillExpand" />
+            <Label Text="{Loc Gas}" MinSize="100 0" />
+            <Control MinSize="50 0" />
+            <OptionButton Name="GasOptions" MinSize="100 0" HorizontalExpand="True" />
        </HBoxContainer>
        <HBoxContainer>
-            <Label Text="{Loc Amount}" CustomMinimumSize="100 0" />
-            <Control CustomMinimumSize="50 0" />
-            <SpinBox Name="AmountSpin" CustomMinimumSize="100 0" SizeFlagsHorizontal="FillExpand" />
+            <Label Text="{Loc Amount}" MinSize="100 0" />
+            <Control MinSize="50 0" />
+            <SpinBox Name="AmountSpin" MinSize="100 0" HorizontalExpand="True" />
        </HBoxContainer>
        <Button Name="SubmitButton" Text="{Loc Add Gas}" />
    </VBoxContainer>
--- a/Content.Client/UserInterface/AdminMenu/Tabs/AtmosTab/AtmosTab.xaml
+++ b/Content.Client/UserInterface/AdminMenu/Tabs/AtmosTab/AtmosTab.xaml
@@ -1,12 +1,10 @@
-<MarginContainer
+<Control
    xmlns="https://spacestation14.io"
    xmlns:amc="clr-namespace:Content.Client.UserInterface.AdminMenu.CustomControls"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:at="clr-namespace:Content.Client.UserInterface.AdminMenu.Tabs.AtmosTab"
-    MarginLeftOverride="4"
-    MarginTopOverride="4" MarginRightOverride="4"
-    MarginBottomOverride="4"
-    CustomMinimumSize="50 50">
+    Margin="4"
+    MinSize="50 50">
    <GridContainer Columns="4">
        <amc:UICommandButton Text="{Loc Add Atmos}" Command="addatmos" WindowType="{x:Type at:AddAtmosWindow}" />
        <amc:UICommandButton Text="{Loc Add Gas}" Command="addgas" WindowType="{x:Type at:AddGasWindow}" />
@@ -14,4 +12,4 @@
        <amc:UICommandButton Text="{Loc Set Temperature}" Command="settemp"
                             WindowType="{x:Type at:SetTemperatureWindow}" />
    </GridContainer>
-</MarginContainer>
+</Control>
--- a/Content.Client/UserInterface/AdminMenu/Tabs/AtmosTab/AtmosTab.xaml.cs
+++ b/Content.Client/UserInterface/AdminMenu/Tabs/AtmosTab/AtmosTab.xaml.cs
@@ -1,11 +1,12 @@
 #nullable enable
 using Robust.Client.AutoGenerated;
+using Robust.Client.UserInterface;
 using Robust.Client.UserInterface.Controls;

 namespace Content.Client.UserInterface.AdminMenu.Tabs.AtmosTab
 {
    [GenerateTypedNameReferences]
-    public partial class AtmosTab : MarginContainer
+    public partial class AtmosTab : Control
    {
    }
 }
--- a/Content.Client/UserInterface/AdminMenu/Tabs/AtmosTab/FillGasWindow.xaml
+++ b/Content.Client/UserInterface/AdminMenu/Tabs/AtmosTab/FillGasWindow.xaml
@@ -2,19 +2,19 @@
    xmlns="https://spacestation14.io" Title="{Loc Fill Gas}">
    <VBoxContainer>
        <HBoxContainer>
-            <Label Text="{Loc Grid}" CustomMinimumSize="100 0" />
-            <Control CustomMinimumSize="50 0" />
-            <OptionButton Name="GridOptions" CustomMinimumSize="100 0" SizeFlagsHorizontal="FillExpand" />
+            <Label Text="{Loc Grid}" MinSize="100 0" />
+            <Control MinSize="50 0" />
+            <OptionButton Name="GridOptions" MinSize="100 0" HorizontalExpand="True" />
        </HBoxContainer>
        <HBoxContainer>
-            <Label Text="{Loc Gas}" CustomMinimumSize="100 0" />
-            <Control CustomMinimumSize="50 0" />
-            <OptionButton Name="GasOptions" CustomMinimumSize="100 0" SizeFlagsHorizontal="FillExpand" />
+            <Label Text="{Loc Gas}" MinSize="100 0" />
+            <Control MinSize="50 0" />
+            <OptionButton Name="GasOptions" MinSize="100 0" HorizontalExpand="True" />
        </HBoxContainer>
        <HBoxContainer>
-            <Label Text="{Loc Amount}" CustomMinimumSize="100 0" />
-            <Control CustomMinimumSize="50 0" />
-            <SpinBox Name="AmountSpin" CustomMinimumSize="100 0" SizeFlagsHorizontal="FillExpand" />
+            <Label Text="{Loc Amount}" MinSize="100 0" />
+            <Control MinSize="50 0" />
+            <SpinBox Name="AmountSpin" MinSize="100 0" HorizontalExpand="True" />
        </HBoxContainer>
        <Button Name="SubmitButton" Text="{Loc Fill Gas}" />
    </VBoxContainer>
--- a/Content.Client/UserInterface/AdminMenu/Tabs/AtmosTab/SetTemperatureWindow.xaml
+++ b/Content.Client/UserInterface/AdminMenu/Tabs/AtmosTab/SetTemperatureWindow.xaml
@@ -2,24 +2,24 @@
    xmlns="https://spacestation14.io" Title="{Loc Set Temperature}">
    <VBoxContainer>
        <HBoxContainer>
-            <Label Text="{Loc Grid}" CustomMinimumSize="100 0" />
-            <Control CustomMinimumSize="50 0" />
-            <OptionButton Name="GridOptions" CustomMinimumSize="100 0" SizeFlagsHorizontal="FillExpand" />
+            <Label Text="{Loc Grid}" MinSize="100 0" />
+            <Control MinSize="50 0" />
+            <OptionButton Name="GridOptions" MinSize="100 0" HorizontalExpand="True" />
        </HBoxContainer>
        <HBoxContainer>
-            <Label Text="{Loc TileX}" CustomMinimumSize="100 0" />
-            <Control CustomMinimumSize="50 0" />
-            <SpinBox Name="TileXSpin" CustomMinimumSize="100 0" SizeFlagsHorizontal="FillExpand" />
+            <Label Text="{Loc TileX}" MinSize="100 0" />
+            <Control MinSize="50 0" />
+            <SpinBox Name="TileXSpin" MinSize="100 0" HorizontalExpand="True" />
        </HBoxContainer>
        <HBoxContainer>
-            <Label Text="{Loc TileY}" CustomMinimumSize="100 0" />
-            <Control CustomMinimumSize="50 0" />
-            <SpinBox Name="TileYSpin" CustomMinimumSize="100 0" SizeFlagsHorizontal="FillExpand" />
+            <Label Text="{Loc TileY}" MinSize="100 0" />
+            <Control MinSize="50 0" />
+            <SpinBox Name="TileYSpin" MinSize="100 0" HorizontalExpand="True" />
        </HBoxContainer>
        <HBoxContainer>
-            <Label Text="{Loc Temperature}" CustomMinimumSize="100 0" />
-            <Control CustomMinimumSize="50 0" />
-            <SpinBox Name="TemperatureSpin" CustomMinimumSize="100 0" SizeFlagsHorizontal="FillExpand" />
+            <Label Text="{Loc Temperature}" MinSize="100 0" />
+            <Control MinSize="50 0" />
+            <SpinBox Name="TemperatureSpin" MinSize="100 0" HorizontalExpand="True" />
        </HBoxContainer>
        <Button Name="SubmitButton" Text="{Loc Set Temperature}" />
    </VBoxContainer>
--- a/Content.Client/UserInterface/AdminMenu/Tabs/PlayerTab.xaml
+++ b/Content.Client/UserInterface/AdminMenu/Tabs/PlayerTab.xaml
@@ -1,15 +1,14 @@
-<MarginContainer
-    xmlns="https://spacestation14.io">
-    <VBoxContainer SizeFlagsVertical="Fill">
-        <HBoxContainer SizeFlagsVertical="Fill">
-            <Label Name="PlayerCount" SizeFlagsHorizontal="FillExpand" SizeFlagsStretchRatio="0.7"
+<Control xmlns="https://spacestation14.io">
+    <VBoxContainer>
+        <HBoxContainer>
+            <Label Name="PlayerCount" HorizontalExpand="True" SizeFlagsStretchRatio="0.7"
                   Text="{Loc Player Count}" />
-            <Button Name="RefreshButton" SizeFlagsHorizontal="FillExpand" SizeFlagsStretchRatio="0.3"
+            <Button Name="RefreshButton" HorizontalExpand="True" SizeFlagsStretchRatio="0.3"
                    Text="{Loc Refresh}" />
        </HBoxContainer>
-        <Control CustomMinimumSize="0 5" />
-        <ScrollContainer SizeFlagsHorizontal="FillExpand" SizeFlagsVertical="FillExpand">
+        <Control MinSize="0 5" />
+        <ScrollContainer HorizontalExpand="True" VerticalExpand="True">
            <VBoxContainer Name="PlayerList" />
        </ScrollContainer>
    </VBoxContainer>
-</MarginContainer>
+</Control>
--- a/Content.Client/UserInterface/AdminMenu/Tabs/PlayerTab.xaml.cs
+++ b/Content.Client/UserInterface/AdminMenu/Tabs/PlayerTab.xaml.cs
@@ -13,7 +13,7 @@ using Robust.Shared.Maths;
 namespace Content.Client.UserInterface.AdminMenu.Tabs
 {
    [GenerateTypedNameReferences]
-    public partial class PlayerTab : MarginContainer
+    public partial class PlayerTab : Control
    {
        public delegate void PlayerListRefresh();

@@ -42,7 +42,7 @@ namespace Content.Client.UserInterface.AdminMenu.Tabs

            var header = new HBoxContainer
            {
-                SizeFlagsHorizontal = SizeFlags.FillExpand,
+                HorizontalExpand = true,
                SeparationOverride = 4,
                Children =
                {
@@ -50,14 +50,14 @@ namespace Content.Client.UserInterface.AdminMenu.Tabs
                    {
                        Text = "Name",
                        SizeFlagsStretchRatio = 2f,
-                        SizeFlagsHorizontal = SizeFlags.FillExpand
+                        HorizontalExpand = true
                    },
                    new VSeparator(),
                    new Label
                    {
                        Text = "Player",
                        SizeFlagsStretchRatio = 2f,
-                        SizeFlagsHorizontal = SizeFlags.FillExpand
+                        HorizontalExpand = true
                    }
                }
            };
@@ -79,7 +79,7 @@ namespace Content.Client.UserInterface.AdminMenu.Tabs
            {
                var hBox = new HBoxContainer
                {
-                    SizeFlagsHorizontal = SizeFlags.FillExpand,
+                    HorizontalExpand = true,
                    SeparationOverride = 4,
                    Children =
                    {
@@ -87,7 +87,7 @@ namespace Content.Client.UserInterface.AdminMenu.Tabs
                        {
                            Text = name,
                            SizeFlagsStretchRatio = 2f,
-                            SizeFlagsHorizontal = SizeFlags.FillExpand,
+                            HorizontalExpand = true,
                            ClipText = true
                        },
                        new VSeparator(),
@@ -95,7 +95,7 @@ namespace Content.Client.UserInterface.AdminMenu.Tabs
                        {
                            Text = player,
                            SizeFlagsStretchRatio = 2f,
-                            SizeFlagsHorizontal = SizeFlags.FillExpand,
+                            HorizontalExpand = true,
                            ClipText = true
                        }
                    }
@@ -121,7 +121,7 @@ namespace Content.Client.UserInterface.AdminMenu.Tabs
        {
            public VSeparator()
            {
-                CustomMinimumSize = (2, 5);
+                MinSize = (2, 5);
                AddChild(new PanelContainer
                {
                    PanelOverride = new StyleBoxFlat
--- a/Content.Client/UserInterface/AdminMenu/Tabs/RoundTab.xaml
+++ b/Content.Client/UserInterface/AdminMenu/Tabs/RoundTab.xaml
@@ -1,14 +1,12 @@
-<MarginContainer
+<Control
    xmlns="https://spacestation14.io"
    xmlns:amc="clr-namespace:Content.Client.UserInterface.AdminMenu.CustomControls"
-    MarginLeftOverride="4"
-    MarginTopOverride="4" MarginRightOverride="4"
-    MarginBottomOverride="4"
-    CustomMinimumSize="50 50">
+    Margin="4"
+    MinSize="50 50">
    <GridContainer
        Columns="4">
        <amc:CommandButton Command="startround" Text="{Loc Start Round}" />
        <amc:CommandButton Command="endround" Text="{Loc End Round}" />
        <amc:CommandButton Command="restartround" Text="{Loc Restart Round}" />
    </GridContainer>
-</MarginContainer>
+</Control>
--- a/Content.Client/UserInterface/AdminMenu/Tabs/RoundTab.xaml.cs
+++ b/Content.Client/UserInterface/AdminMenu/Tabs/RoundTab.xaml.cs
@@ -1,11 +1,12 @@
 #nullable enable
 using Robust.Client.AutoGenerated;
+using Robust.Client.UserInterface;
 using Robust.Client.UserInterface.Controls;

 namespace Content.Client.UserInterface.AdminMenu.Tabs
 {
    [GenerateTypedNameReferences]
-    public partial class RoundTab : MarginContainer
+    public partial class RoundTab : Control
    {
    }
 }
--- a/Content.Client/UserInterface/AdminMenu/Tabs/ServerTab.xaml
+++ b/Content.Client/UserInterface/AdminMenu/Tabs/ServerTab.xaml
@@ -1,13 +1,11 @@
-<MarginContainer
+<Control
    xmlns="https://spacestation14.io"
    xmlns:amc="clr-namespace:Content.Client.UserInterface.AdminMenu.CustomControls"
-    MarginLeftOverride="4"
-    MarginTopOverride="4" MarginRightOverride="4"
-    MarginBottomOverride="4"
-    CustomMinimumSize="50 50">
+    Margin="4"
+    MinSize="50 50">
    <GridContainer
        Columns="4" >
        <amc:CommandButton Command="restart" Text="{Loc Reboot}"></amc:CommandButton>
        <amc:CommandButton Command="shutdown" Text="{Loc Shutdown}"></amc:CommandButton>
    </GridContainer>
-</MarginContainer>
+</Control>
--- a/Content.Client/UserInterface/AdminMenu/Tabs/ServerTab.xaml.cs
+++ b/Content.Client/UserInterface/AdminMenu/Tabs/ServerTab.xaml.cs
@@ -1,14 +1,12 @@
 #nullable enable
 using Robust.Client.AutoGenerated;
+using Robust.Client.UserInterface;
 using Robust.Client.UserInterface.Controls;

 namespace Content.Client.UserInterface.AdminMenu.Tabs
 {
    [GenerateTypedNameReferences]
-    public partial class ServerTab : MarginContainer
+    public partial class ServerTab : Control
    {
-        public ServerTab()
-        {
-        }
    }
 }
--- a/Content.Client/UserInterface/AlertsUI.cs
+++ b/Content.Client/UserInterface/AlertsUI.cs
@@ -1,7 +1,6 @@
 using Content.Client.UserInterface.Stylesheets;
 using Robust.Client.UserInterface;
 using Robust.Client.UserInterface.Controls;
-using Robust.Shared.Maths;

 namespace Content.Client.UserInterface
 {
@@ -25,37 +24,35 @@ namespace Content.Client.UserInterface
            var panelContainer = new PanelContainer
            {
                StyleClasses = {StyleNano.StyleClassTransparentBorderedWindowPanel},
-                SizeFlagsHorizontal = SizeFlags.ShrinkEnd,
-                SizeFlagsVertical = SizeFlags.None
+                HorizontalAlignment = HAlignment.Right,
+                VerticalAlignment = VAlignment.Top
            };
            AddChild(panelContainer);

            Grid = new GridContainer
            {
-                MaxHeight = 64,
+                MaxGridHeight = 64,
                ExpandBackwards = true
            };
            panelContainer.AddChild(Grid);
+
+            MinSize = (64, 64);
        }

+        // This makes no sense but I'm leaving it in place in case I break anything by removing it.
+
        protected override void Resized()
        {
            // TODO: Can rework this once https://github.com/space-wizards/RobustToolbox/issues/1392 is done,
            // this is here because there isn't currently a good way to allow the grid to adjust its height based
            // on constraints, otherwise we would use anchors to lay it out
            base.Resized();
-            Grid.MaxHeight = Height;
-        }
-
-        protected override Vector2 CalculateMinimumSize()
-        {
-            // allows us to shrink down to a single row
-            return (64, 64);
+            Grid.MaxGridHeight = Height;
        }

        protected override void UIScaleChanged()
        {
-            Grid.MaxHeight = Height;
+            Grid.MaxGridHeight = Height;
            base.UIScaleChanged();
        }
    }
--- a/Content.Client/UserInterface/Atmos/GasTank/GasTankWindow.cs
+++ b/Content.Client/UserInterface/Atmos/GasTank/GasTankWindow.cs
@@ -72,7 +72,7 @@ namespace Content.Client.UserInterface.Atmos.GasTank
                Children =
                {
                    (_topContainer = new VBoxContainer()),
-                    new Control {CustomMinimumSize = (0, 110)}
+                    new Control {MinSize = (0, 110)}
                }
            };

@@ -82,37 +82,26 @@ namespace Content.Client.UserInterface.Atmos.GasTank

            var font = _resourceCache.GetFont("/Fonts/Boxfont-round/Boxfont Round.ttf", 13);

-            var topRow = new MarginContainer
+            var topRow = new HBoxContainer
            {
-                MarginLeftOverride = 4,
-                MarginTopOverride = 2,
-                MarginRightOverride = 12,
-                MarginBottomOverride = 2,
+                Margin = new Thickness(4, 2, 12, 2),
                Children =
                {
-                    new HBoxContainer
+                    (_lblName = new Label
                    {
-                        Children =
-                        {
-                            (_lblName = new Label
-                            {
-                                Text = Loc.GetString("Gas Tank"),
-                                FontOverride = font,
-                                FontColorOverride = StyleNano.NanoGold,
-                                SizeFlagsVertical = SizeFlags.ShrinkCenter
-                            }),
-                            new Control
-                            {
-                                CustomMinimumSize = (20, 0),
-                                SizeFlagsHorizontal = SizeFlags.Expand
-                            },
-                            (btnClose = new TextureButton
-                            {
-                                StyleClasses = {SS14Window.StyleClassWindowCloseButton},
-                                SizeFlagsVertical = SizeFlags.ShrinkCenter
-                            })
-                        }
-                    }
+                        Text = Loc.GetString("Gas Tank"),
+                        FontOverride = font,
+                        FontColorOverride = StyleNano.NanoGold,
+                        VerticalAlignment = VAlignment.Center,
+                        HorizontalExpand = true,
+                        HorizontalAlignment = HAlignment.Left,
+                        Margin = new Thickness(0, 0, 20, 0),
+                    }),
+                    (btnClose = new TextureButton
+                    {
+                        StyleClasses = {SS14Window.StyleClassWindowCloseButton},
+                        VerticalAlignment = VAlignment.Center
+                    })
                }
            };

@@ -121,30 +110,23 @@ namespace Content.Client.UserInterface.Atmos.GasTank
                PanelOverride = new StyleBoxFlat {BackgroundColor = Color.FromHex("#202025")},
                Children =
                {
-                    new MarginContainer
+                    (_contentContainer = new VBoxContainer
                    {
-                        MarginLeftOverride = 8,
-                        MarginRightOverride = 8,
-                        MarginTopOverride = 4,
-                        MarginBottomOverride = 4,
-                        Children =
-                        {
-                            (_contentContainer = new VBoxContainer())
-                        }
-                    }
+                        Margin = new Thickness(8, 4),
+                    })
                }
            };

            _topContainer.AddChild(topRow);
            _topContainer.AddChild(new PanelContainer
            {
-                CustomMinimumSize = (0, 2),
+                MinSize = (0, 2),
                PanelOverride = new StyleBoxFlat {BackgroundColor = Color.FromHex("#525252ff")}
            });
            _topContainer.AddChild(middle);
            _topContainer.AddChild(new PanelContainer
            {
-                CustomMinimumSize = (0, 2),
+                MinSize = (0, 2),
                PanelOverride = new StyleBoxFlat {BackgroundColor = Color.FromHex("#525252ff")}
            });

@@ -154,26 +136,20 @@ namespace Content.Client.UserInterface.Atmos.GasTank

            //internals
            _lblInternals = new RichTextLabel
-                {CustomMinimumSize = (200, 0), SizeFlagsVertical = SizeFlags.ShrinkCenter};
+                {MinSize = (200, 0), VerticalAlignment = VAlignment.Center};
            _btnInternals = new Button {Text = Loc.GetString("Toggle")};

            _contentContainer.AddChild(
-                new MarginContainer
+                new HBoxContainer
                {
-                    MarginTopOverride = 7,
-                    Children =
-                    {
-                        new HBoxContainer
-                        {
-                            Children = {_lblInternals, _btnInternals}
-                        }
-                    }
+                    Margin = new Thickness(0, 7, 0, 0),
+                    Children = {_lblInternals, _btnInternals}
                });

            // Separator
            _contentContainer.AddChild(new Control
            {
-                CustomMinimumSize = new Vector2(0, 10)
+                MinSize = new Vector2(0, 10)
            });

            _contentContainer.AddChild(new Label
@@ -181,19 +157,12 @@ namespace Content.Client.UserInterface.Atmos.GasTank
                Text = Loc.GetString("Output Pressure"),
                Align = Label.AlignMode.Center
            });
-            _spbPressure = new FloatSpinBox {IsValid = f => f >= 0 || f <= 3000};
-            _contentContainer.AddChild(
-                new MarginContainer
-                {
-                    MarginRightOverride = 25,
-                    MarginLeftOverride = 25,
-                    MarginBottomOverride = 7,
-                    Children =
-                    {
-                        _spbPressure
-                    }
-                }
-            );
+            _spbPressure = new FloatSpinBox
+            {
+                IsValid = f => f >= 0 || f <= 3000,
+                Margin = new Thickness(25, 0, 25, 7)
+            };
+            _contentContainer.AddChild(_spbPressure);

            // Handlers
            _spbPressure.OnValueChanged += args =>
--- a/Content.Client/UserInterface/Cargo/CargoConsoleMenu.cs
+++ b/Content.Client/UserInterface/Cargo/CargoConsoleMenu.cs
@@ -15,8 +15,6 @@ namespace Content.Client.UserInterface.Cargo
 {
    public class CargoConsoleMenu : SS14Window
    {
-        protected override Vector2? CustomSize => (400, 600);
-
        public CargoConsoleBoundUserInterface Owner { get; private set; }

        public event Action<BaseButton.ButtonEventArgs> OnItemSelected;
@@ -42,6 +40,7 @@ namespace Content.Client.UserInterface.Cargo

        public CargoConsoleMenu(CargoConsoleBoundUserInterface owner)
        {
+            SetSize = MinSize = (400, 600);
            IoCManager.InjectDependencies(this);
            Owner = owner;

@@ -112,7 +111,7 @@ namespace Content.Client.UserInterface.Cargo
                //Text = Loc.GetString("Call Shuttle"),
                Text = Loc.GetString("Activate Telepad"), //Shuttle code pending
                TextAlign = Label.AlignMode.Center,
-                SizeFlagsHorizontal = SizeFlags.FillExpand
+                HorizontalExpand = true
            };
            PermissionsButton = new Button()
            {
@@ -127,13 +126,13 @@ namespace Content.Client.UserInterface.Cargo
            _categories = new OptionButton
            {
                Prefix = Loc.GetString("Categories: "),
-                SizeFlagsHorizontal = SizeFlags.FillExpand,
+                HorizontalExpand = true,
                SizeFlagsStretchRatio = 1
            };
            _searchBar = new LineEdit
            {
                PlaceHolder = Loc.GetString("Search"),
-                SizeFlagsHorizontal = SizeFlags.FillExpand,
+                HorizontalExpand = true,
                SizeFlagsStretchRatio = 1
            };
            category.AddChild(_categories);
@@ -142,41 +141,41 @@ namespace Content.Client.UserInterface.Cargo

            var products = new ScrollContainer()
            {
-                SizeFlagsHorizontal = SizeFlags.FillExpand,
-                SizeFlagsVertical = SizeFlags.FillExpand,
+                HorizontalExpand = true,
+                VerticalExpand = true,
                SizeFlagsStretchRatio = 6
            };
            Products = new VBoxContainer()
            {
-                SizeFlagsHorizontal = SizeFlags.FillExpand,
-                SizeFlagsVertical = SizeFlags.FillExpand
+                HorizontalExpand = true,
+                VerticalExpand = true
            };
            products.AddChild(Products);
            rows.AddChild(products);

            var requestsAndOrders = new PanelContainer
            {
-                SizeFlagsVertical = SizeFlags.FillExpand,
+                VerticalExpand = true,
                SizeFlagsStretchRatio = 6,
                PanelOverride = new StyleBoxFlat { BackgroundColor = Color.Black }
            };
            var orderScrollBox = new ScrollContainer
            {
-                SizeFlagsVertical = SizeFlags.FillExpand
+                VerticalExpand = true
            };
            var rAndOVBox = new VBoxContainer();
            var requestsLabel = new Label { Text = Loc.GetString("Requests") };
            _requests = new VBoxContainer // replace with scroll box so that approval buttons can be added
            {
                StyleClasses = { "transparentItemList" },
-                SizeFlagsVertical = SizeFlags.FillExpand,
+                VerticalExpand = true,
                SizeFlagsStretchRatio = 1,
            };
            var ordersLabel = new Label { Text = Loc.GetString("Orders") };
            _orders = new VBoxContainer
            {
                StyleClasses = { "transparentItemList" },
-                SizeFlagsVertical = SizeFlags.FillExpand,
+                VerticalExpand = true,
                SizeFlagsStretchRatio = 1,
            };
            rAndOVBox.AddChild(requestsLabel);
@@ -189,7 +188,7 @@ namespace Content.Client.UserInterface.Cargo

            rows.AddChild(new TextureButton
            {
-                SizeFlagsVertical = SizeFlags.FillExpand,
+                VerticalExpand = true,
            });
            Contents.AddChild(rows);

@@ -351,30 +350,30 @@ namespace Content.Client.UserInterface.Cargo

        public CargoProductRow()
        {
-            SizeFlagsHorizontal = SizeFlags.FillExpand;
+            HorizontalExpand = true;

            MainButton = new Button
            {
-                SizeFlagsHorizontal = SizeFlags.FillExpand,
-                SizeFlagsVertical = SizeFlags.FillExpand
+                HorizontalExpand = true,
+                VerticalExpand = true
            };
            AddChild(MainButton);

            var hBox = new HBoxContainer
            {
-                SizeFlagsHorizontal = SizeFlags.FillExpand
+                HorizontalExpand = true
            };

            Icon = new TextureRect
            {
-                CustomMinimumSize = new Vector2(32.0f, 32.0f),
+                MinSize = new Vector2(32.0f, 32.0f),
                RectClipContent = true
            };
            hBox.AddChild(Icon);

            ProductName = new Label
            {
-                SizeFlagsHorizontal = SizeFlags.FillExpand
+                HorizontalExpand = true
            };
            hBox.AddChild(ProductName);

@@ -384,7 +383,7 @@ namespace Content.Client.UserInterface.Cargo
            };
            PointCost = new Label
            {
-                CustomMinimumSize = new Vector2(40.0f, 32.0f),
+                MinSize = new Vector2(40.0f, 32.0f),
                Align = Label.AlignMode.Right
            };
            panel.AddChild(PointCost);
@@ -405,34 +404,34 @@ namespace Content.Client.UserInterface.Cargo

        public CargoOrderRow()
        {
-            SizeFlagsHorizontal = SizeFlags.FillExpand;
+            HorizontalExpand = true;

            var hBox = new HBoxContainer
            {
-                SizeFlagsHorizontal = SizeFlags.FillExpand,
+                HorizontalExpand = true,
            };

            Icon = new TextureRect
            {
-                CustomMinimumSize = new Vector2(32.0f, 32.0f),
+                MinSize = new Vector2(32.0f, 32.0f),
                RectClipContent = true
            };
            hBox.AddChild(Icon);

            var vBox = new VBoxContainer
            {
-                SizeFlagsHorizontal = SizeFlags.FillExpand,
-                SizeFlagsVertical = SizeFlags.FillExpand
+                HorizontalExpand = true,
+                VerticalExpand = true
            };
            ProductName = new Label
            {
-                SizeFlagsHorizontal = SizeFlags.FillExpand,
+                HorizontalExpand = true,
                StyleClasses = { StyleNano.StyleClassLabelSubText },
                ClipText = true
            };
            Description = new Label
            {
-                SizeFlagsHorizontal = SizeFlags.FillExpand,
+                HorizontalExpand = true,
                StyleClasses = { StyleNano.StyleClassLabelSubText },
                ClipText = true
            };
--- a/Content.Client/UserInterface/Cargo/CargoConsoleOrderMenu.cs
+++ b/Content.Client/UserInterface/Cargo/CargoConsoleOrderMenu.cs
@@ -35,7 +35,7 @@ namespace Content.Client.UserInterface.Cargo
            var amountLabel = new Label { Text = Loc.GetString("Amount:") };
            Amount = new SpinBox
            {
-                SizeFlagsHorizontal = SizeFlags.FillExpand,
+                HorizontalExpand = true,
                Value = 1
            };
            Amount.SetButtons(new List<int>() { -100, -10, -1 }, new List<int>() { 1, 10, 100 });
--- a/Content.Client/UserInterface/Cargo/GalacticBankSelectionMenu.cs
+++ b/Content.Client/UserInterface/Cargo/GalacticBankSelectionMenu.cs
@@ -16,27 +16,18 @@ namespace Content.Client.UserInterface.Cargo
        private int[] _accountIds = new int[] { };
        private int _selectedAccountId = -1;

-        protected override Vector2? CustomSize => (300, 300);
-
        public CargoConsoleBoundUserInterface Owner;

        public GalacticBankSelectionMenu()
        {
+            MinSize = SetSize = (300, 300);
            IoCManager.InjectDependencies(this);

            Title = Loc.GetString("Galactic Bank Selection");

            _accounts = new ItemList() { SelectMode = ItemList.ItemListSelectMode.Single };

-            var margin = new MarginContainer()
-            {
-                SizeFlagsVertical = SizeFlags.FillExpand,
-                SizeFlagsHorizontal = SizeFlags.FillExpand,
-            };
-
-            margin.AddChild(_accounts);
-
-            Contents.AddChild(margin);
+            Contents.AddChild(_accounts);
        }

        public void Populate(int accountCount, string[] accountNames, int[] accountIds, int selectedAccountId)
--- a/Content.Client/UserInterface/CharacterSetupGui.cs
+++ b/Content.Client/UserInterface/CharacterSetupGui.cs
@@ -36,12 +36,9 @@ namespace Content.Client.UserInterface
        {
            _entityManager = entityManager;
            _preferencesManager = preferencesManager;
-            var margin = new MarginContainer
+            var margin = new Control
            {
-                MarginBottomOverride = 20,
-                MarginLeftOverride = 20,
-                MarginRightOverride = 20,
-                MarginTopOverride = 20
+                Margin = new Thickness(20),
            };

            AddChild(margin);
@@ -67,32 +64,25 @@ namespace Content.Client.UserInterface

            var topHBox = new HBoxContainer
            {
-                CustomMinimumSize = (0, 40),
+                MinSize = (0, 40),
                Children =
                {
-                    new MarginContainer
+                    new Label
                    {
-                        MarginLeftOverride = 8,
-                        Children =
-                        {
-                            new Label
-                            {
-                                Text = Loc.GetString("Character Setup"),
-                                StyleClasses = {StyleNano.StyleClassLabelHeadingBigger},
-                                VAlign = Label.VAlignMode.Center,
-                                SizeFlagsHorizontal = SizeFlags.Expand | SizeFlags.ShrinkCenter
-                            }
-                        }
+                        Margin = new Thickness(8, 0, 0, 0),
+                        Text = Loc.GetString("Character Setup"),
+                        StyleClasses = {StyleNano.StyleClassLabelHeadingBigger},
+                        VAlign = Label.VAlignMode.Center,
                    },
                    (SaveButton = new Button
                    {
-                        SizeFlagsHorizontal = SizeFlags.Expand | SizeFlags.ShrinkEnd,
+                        HorizontalExpand = true,
+                        HorizontalAlignment = HAlignment.Right,
                        Text = Loc.GetString("Save"),
                        StyleClasses = {StyleNano.StyleClassButtonBig},
                    }),
                    (CloseButton = new Button
                    {
-                        SizeFlagsHorizontal = SizeFlags.ShrinkEnd,
                        Text = Loc.GetString("Close"),
                        StyleClasses = {StyleNano.StyleClassButtonBig},
                    })
@@ -112,29 +102,20 @@ namespace Content.Client.UserInterface

            var hBox = new HBoxContainer
            {
-                SizeFlagsVertical = SizeFlags.FillExpand,
+                VerticalExpand = true,
                SeparationOverride = 0
            };
            vBox.AddChild(hBox);

            _charactersVBox = new VBoxContainer();

-            hBox.AddChild(new MarginContainer
+            hBox.AddChild(new ScrollContainer
            {
-                CustomMinimumSize = (330, 0),
-                SizeFlagsHorizontal = SizeFlags.Fill,
-                MarginTopOverride = 5,
-                MarginLeftOverride = 5,
+                MinSize = (325, 0),
+                Margin = new Thickness(5, 5, 0, 0),
                Children =
                {
-                    new ScrollContainer
-                    {
-                        SizeFlagsVertical = SizeFlags.FillExpand,
-                        Children =
-                        {
-                            _charactersVBox
-                        }
-                    }
+                    _charactersVBox
                }
            });

@@ -152,7 +133,7 @@ namespace Content.Client.UserInterface
            hBox.AddChild(new PanelContainer
            {
                PanelOverride = new StyleBoxFlat {BackgroundColor = StyleNano.NanoGold},
-                CustomMinimumSize = (2, 0)
+                MinSize = (2, 0)
            });
            _humanoidProfileEditor = new HumanoidProfileEditor(preferencesManager, prototypeManager, entityManager);
            _humanoidProfileEditor.OnProfileChanged += newProfile => { UpdateUI(); };
@@ -266,7 +247,7 @@ namespace Content.Client.UserInterface
                {
                    Text = description,
                    ClipText = true,
-                    SizeFlagsHorizontal = SizeFlags.FillExpand
+                    HorizontalExpand = true
                };
                var deleteButton = new Button
                {
@@ -281,7 +262,7 @@ namespace Content.Client.UserInterface

                var internalHBox = new HBoxContainer
                {
-                    SizeFlagsHorizontal = SizeFlags.FillExpand,
+                    HorizontalExpand = true,
                    SeparationOverride = 0,
                    Children =
                    {
--- a/Content.Client/UserInterface/Controls/ActionSlot.cs
+++ b/Content.Client/UserInterface/Controls/ActionSlot.cs
@@ -131,8 +131,8 @@ namespace Content.Client.UserInterface.Controls
            SlotIndex = slotIndex;
            MouseFilter = MouseFilterMode.Stop;

-            CustomMinimumSize = (64, 64);
-            SizeFlagsVertical = SizeFlags.None;
+            MinSize = (64, 64);
+            VerticalAlignment = VAlignment.Top;
            TooltipDelay = CustomTooltipDelay;
            TooltipSupplier = SupplyTooltip;

@@ -144,29 +144,29 @@ namespace Content.Client.UserInterface.Controls

            _bigActionIcon = new TextureRect
            {
-                SizeFlagsHorizontal = SizeFlags.FillExpand,
-                SizeFlagsVertical = SizeFlags.FillExpand,
+                HorizontalExpand = true,
+                VerticalExpand = true,
                Stretch = TextureRect.StretchMode.Scale,
                Visible = false
            };
            _bigItemSpriteView = new SpriteView
            {
-                SizeFlagsHorizontal = SizeFlags.FillExpand,
-                SizeFlagsVertical = SizeFlags.FillExpand,
+                HorizontalExpand = true,
+                VerticalExpand = true,
                Scale = (2,2),
                Visible = false
            };
            _smallActionIcon = new TextureRect
            {
-                SizeFlagsHorizontal = SizeFlags.ShrinkEnd,
-                SizeFlagsVertical = SizeFlags.ShrinkEnd,
+                HorizontalAlignment = HAlignment.Right,
+                VerticalAlignment = VAlignment.Bottom,
                Stretch = TextureRect.StretchMode.Scale,
                Visible = false
            };
            _smallItemSpriteView = new SpriteView
            {
-                SizeFlagsHorizontal = SizeFlags.ShrinkEnd,
-                SizeFlagsVertical = SizeFlags.ShrinkEnd,
+                HorizontalAlignment = HAlignment.Right,
+                VerticalAlignment = VAlignment.Bottom,
                Visible = false
            };

@@ -175,28 +175,26 @@ namespace Content.Client.UserInterface.Controls
            // padding to the left of the number to shift it right
            var paddingBox = new HBoxContainer()
            {
-                SizeFlagsHorizontal = SizeFlags.FillExpand,
-                SizeFlagsVertical = SizeFlags.FillExpand,
-                CustomMinimumSize = (64, 64)
+                HorizontalExpand = true,
+                VerticalExpand = true,
+                MinSize = (64, 64)
            };
            paddingBox.AddChild(new Control()
            {
-                CustomMinimumSize = (4, 4),
-                SizeFlagsVertical = SizeFlags.Fill
+                MinSize = (4, 4),
            });
            paddingBox.AddChild(_number);

            // padding to the left of the small icon
            var paddingBoxItemIcon = new HBoxContainer()
            {
-                SizeFlagsHorizontal = SizeFlags.FillExpand,
-                SizeFlagsVertical = SizeFlags.FillExpand,
-                CustomMinimumSize = (64, 64)
+                HorizontalExpand = true,
+                VerticalExpand = true,
+                MinSize = (64, 64)
            };
            paddingBoxItemIcon.AddChild(new Control()
            {
-                CustomMinimumSize = (32, 32),
-                SizeFlagsVertical = SizeFlags.Fill
+                MinSize = (32, 32),
            });
            paddingBoxItemIcon.AddChild(new Control
            {
--- a/Content.Client/UserInterface/CreditsWindow.cs
+++ b/Content.Client/UserInterface/CreditsWindow.cs
@@ -38,9 +38,18 @@ namespace Content.Client.UserInterface

            var rootContainer = new TabContainer();

-            var patronsList = new ScrollContainer();
-            var ss14ContributorsList = new ScrollContainer();
-            var licensesList = new ScrollContainer();
+            var patronsList = new ScrollContainer
+            {
+                HScrollEnabled = false
+            };
+            var ss14ContributorsList = new ScrollContainer
+            {
+                HScrollEnabled = false
+            };
+            var licensesList = new ScrollContainer
+            {
+                HScrollEnabled = false
+            };

            rootContainer.AddChild(ss14ContributorsList);
            rootContainer.AddChild(patronsList);
@@ -56,14 +65,15 @@ namespace Content.Client.UserInterface

            Contents.AddChild(rootContainer);

-            CustomMinimumSize = (650, 450);
+            SetSize = (650, 650);
        }

        private void PopulateLicenses(ScrollContainer licensesList)
        {
-            var margin = new MarginContainer {MarginLeftOverride = 2, MarginTopOverride = 2};
-            var vBox = new VBoxContainer();
-            margin.AddChild(vBox);
+            var vBox = new VBoxContainer
+            {
+                Margin = new Thickness(2, 2, 0, 0)
+            };

            foreach (var entry in CreditsManager.GetLicenses().OrderBy(p => p.Name))
            {
@@ -77,14 +87,15 @@ namespace Content.Client.UserInterface
                }
            }

-            licensesList.AddChild(margin);
+            licensesList.AddChild(vBox);
        }

        private void PopulatePatronsList(Control patronsList)
        {
-            var margin = new MarginContainer {MarginLeftOverride = 2, MarginTopOverride = 2};
-            var vBox = new VBoxContainer();
-            margin.AddChild(vBox);
+            var vBox = new VBoxContainer
+            {
+                Margin = new Thickness(2, 2, 0, 0)
+            };
            var patrons = LoadPatrons();

            // Do not show "become a patron" button on Steam builds
@@ -95,7 +106,7 @@ namespace Content.Client.UserInterface
                vBox.AddChild(patronButton = new Button
                {
                    Text = "Become a Patron",
-                    SizeFlagsHorizontal = SizeFlags.ShrinkCenter
+                    HorizontalAlignment = HAlignment.Center
                });

                patronButton.OnPressed +=
@@ -107,7 +118,7 @@ namespace Content.Client.UserInterface
            {
                if (!first)
                {
-                    vBox.AddChild(new Control {CustomMinimumSize = (0, 10)});
+                    vBox.AddChild(new Control {MinSize = (0, 10)});
                }

                first = false;
@@ -123,7 +134,7 @@ namespace Content.Client.UserInterface



-            patronsList.AddChild(margin);
+            patronsList.AddChild(vBox);
        }

        private IEnumerable<PatronEntry> LoadPatrons()
@@ -140,17 +151,14 @@ namespace Content.Client.UserInterface
        {
            Button contributeButton;

-            var margin = new MarginContainer
+            var vBox = new VBoxContainer
            {
-                MarginLeftOverride = 2,
-                MarginTopOverride = 2
+                Margin = new Thickness(2, 2, 0, 0)
            };
-            var vBox = new VBoxContainer();
-            margin.AddChild(vBox);

            vBox.AddChild(new HBoxContainer
            {
-                SizeFlagsHorizontal = SizeFlags.ShrinkCenter,
+                HorizontalAlignment = HAlignment.Center,
                SeparationOverride = 20,
                Children =
                {
@@ -165,7 +173,7 @@ namespace Content.Client.UserInterface
            {
                if (!first)
                {
-                    vBox.AddChild(new Control {CustomMinimumSize = (0, 10)});
+                    vBox.AddChild(new Control {MinSize = (0, 10)});
                }

                first = false;
@@ -190,7 +198,7 @@ namespace Content.Client.UserInterface
            AddSection("Original Space Station 13 Remake Team", "OriginalRemake.txt");
            AddSection("Special Thanks", "SpecialThanks.txt", true);

-            contributorsList.AddChild(margin);
+            contributorsList.AddChild(vBox);

            contributeButton.OnPressed += _ =>
                IoCManager.Resolve<IUriOpener>().OpenUri(UILinks.GitHub);
--- a/Content.Client/UserInterface/GameHud.cs
+++ b/Content.Client/UserInterface/GameHud.cs
@@ -132,7 +132,7 @@ namespace Content.Client.UserInterface

        public void Initialize()
        {
-            RootControl = new LC();
+            RootControl = new LC { Name = "AAAAAAAAAAAAAAAAAAAAAA"};
            LC.SetAnchorPreset(RootControl, LC.LayoutPreset.Wide);

            var escapeTexture = _resourceCache.GetTexture("/Textures/Interface/hamburger.svg.192dpi.png");
@@ -162,7 +162,7 @@ namespace Content.Client.UserInterface
            _buttonEscapeMenu = new TopButton(escapeTexture, EngineKeyFunctions.EscapeMenu, _inputManager)
            {
                ToolTip = Loc.GetString("Open escape menu."),
-                CustomMinimumSize = (70, 64),
+                MinSize = (70, 64),
                StyleClasses = {StyleBase.ButtonOpenRight}
            };

@@ -174,7 +174,7 @@ namespace Content.Client.UserInterface
            _buttonCharacterMenu = new TopButton(characterTexture, ContentKeyFunctions.OpenCharacterMenu, _inputManager)
            {
                ToolTip = Loc.GetString("Open character menu."),
-                CustomMinimumSize = topMinSize,
+                MinSize = topMinSize,
                Visible = false,
                StyleClasses = {StyleBase.ButtonSquare}
            };
@@ -187,7 +187,7 @@ namespace Content.Client.UserInterface
            _buttonInventoryMenu = new TopButton(inventoryTexture, ContentKeyFunctions.OpenInventoryMenu, _inputManager)
            {
                ToolTip = Loc.GetString("Open inventory menu."),
-                CustomMinimumSize = topMinSize,
+                MinSize = topMinSize,
                Visible = false,
                StyleClasses = {StyleBase.ButtonSquare}
            };
@@ -200,7 +200,7 @@ namespace Content.Client.UserInterface
            _buttonCraftingMenu = new TopButton(craftingTexture, ContentKeyFunctions.OpenCraftingMenu, _inputManager)
            {
                ToolTip = Loc.GetString("Open crafting menu."),
-                CustomMinimumSize = topMinSize,
+                MinSize = topMinSize,
                Visible = false,
                StyleClasses = {StyleBase.ButtonSquare}
            };
@@ -213,7 +213,7 @@ namespace Content.Client.UserInterface
            _buttonActionsMenu = new TopButton(actionsTexture, ContentKeyFunctions.OpenActionsMenu, _inputManager)
            {
                ToolTip = Loc.GetString("Open actions menu."),
-                CustomMinimumSize = topMinSize,
+                MinSize = topMinSize,
                Visible = false,
                StyleClasses = {StyleBase.ButtonSquare}
            };
@@ -226,7 +226,7 @@ namespace Content.Client.UserInterface
            _buttonAdminMenu = new TopButton(adminTexture, ContentKeyFunctions.OpenAdminMenu, _inputManager)
            {
                ToolTip = Loc.GetString("Open admin menu."),
-                CustomMinimumSize = topMinSize,
+                MinSize = topMinSize,
                Visible = false,
                StyleClasses = {StyleBase.ButtonSquare}
            };
@@ -239,7 +239,7 @@ namespace Content.Client.UserInterface
            _buttonSandboxMenu = new TopButton(sandboxTexture, ContentKeyFunctions.OpenSandboxWindow, _inputManager)
            {
                ToolTip = Loc.GetString("Open sandbox menu."),
-                CustomMinimumSize = topMinSize,
+                MinSize = topMinSize,
                Visible = false,
                StyleClasses = {StyleBase.ButtonSquare}
            };
@@ -252,7 +252,7 @@ namespace Content.Client.UserInterface
            _buttonTutorial = new TopButton(tutorialTexture, ContentKeyFunctions.OpenTutorial, _inputManager)
            {
                ToolTip = Loc.GetString("Open tutorial."),
-                CustomMinimumSize = topMinSize,
+                MinSize = topMinSize,
                StyleClasses = {StyleBase.ButtonOpenLeft, TopButton.StyleClassRedTopButton},
            };

@@ -300,25 +300,25 @@ namespace Content.Client.UserInterface
            LC.SetMarginBottom(centerBottomContainer, -10f);
            RootControl.AddChild(centerBottomContainer);

-            HandsContainer = new MarginContainer
+            HandsContainer = new Control
            {
-                SizeFlagsVertical = Control.SizeFlags.ShrinkEnd
+                VerticalAlignment = Control.VAlignment.Bottom,
            };
-            RightInventoryQuickButtonContainer = new MarginContainer
+            RightInventoryQuickButtonContainer = new Control
            {
-                SizeFlagsVertical = Control.SizeFlags.ShrinkEnd
+                VerticalAlignment = Control.VAlignment.Bottom,
            };
-            LeftInventoryQuickButtonContainer = new MarginContainer
+            LeftInventoryQuickButtonContainer = new Control
            {
-                SizeFlagsVertical = Control.SizeFlags.ShrinkEnd
+                VerticalAlignment = Control.VAlignment.Bottom,
            };
            centerBottomContainer.AddChild(LeftInventoryQuickButtonContainer);
            centerBottomContainer.AddChild(HandsContainer);
            centerBottomContainer.AddChild(RightInventoryQuickButtonContainer);

-            SuspicionContainer = new MarginContainer
+            SuspicionContainer = new Control
            {
-                SizeFlagsHorizontal = Control.SizeFlags.ShrinkCenter
+                HorizontalAlignment = Control.HAlignment.Center
            };

            RootControl.AddChild(SuspicionContainer);
@@ -330,7 +330,7 @@ namespace Content.Client.UserInterface

            _topNotificationContainer = new VBoxContainer
            {
-                CustomMinimumSize = (600, 0)
+                MinSize = (600, 0)
            };
            RootControl.AddChild(_topNotificationContainer);
            LC.SetAnchorPreset(_topNotificationContainer, LC.LayoutPreset.CenterTop);
@@ -498,21 +498,21 @@ namespace Content.Client.UserInterface
                    {
                        Children =
                        {
-                            new Control {CustomMinimumSize = (0, VertPad)},
                            (_textureRect = new TextureRect
                            {
                                TextureScale = (0.5f, 0.5f),
                                Texture = texture,
-                                SizeFlagsHorizontal = SizeFlags.ShrinkCenter,
-                                SizeFlagsVertical = SizeFlags.Expand | SizeFlags.ShrinkCenter,
+                                HorizontalAlignment = HAlignment.Center,
+                                VerticalAlignment = VAlignment.Center,
+                                VerticalExpand = true,
+                                Margin = new Thickness(0, VertPad),
                                ModulateSelfOverride = NormalColor,
                                Stretch = TextureRect.StretchMode.KeepCentered
                            }),
-                            new Control {CustomMinimumSize = (0, VertPad)},
                            (_label = new Label
                            {
                                Text = ShortKeyName(_function),
-                                SizeFlagsHorizontal = SizeFlags.ShrinkCenter,
+                                HorizontalAlignment = HAlignment.Center,
                                ModulateSelfOverride = NormalColor,
                                StyleClasses = {StyleClassLabelTopButton}
                            })
--- a/Content.Client/UserInterface/GhostGui.cs
+++ b/Content.Client/UserInterface/GhostGui.cs
@@ -54,41 +54,33 @@ namespace Content.Client.UserInterface

    public class GhostTargetWindow : SS14Window
    {
-        protected override Vector2? CustomSize => (300, 450);
        private readonly GhostComponent _owner;
        private readonly VBoxContainer _buttonContainer;

        public GhostTargetWindow(GhostComponent owner)
        {
+            MinSize = SetSize = (300, 450);
            Title = "Ghost Warp";
            _owner = owner;
            _owner.GhostRequestWarpPoint();
            _owner.GhostRequestPlayerNames();

-            var margin = new MarginContainer()
-            {
-                SizeFlagsVertical = SizeFlags.FillExpand,
-                SizeFlagsHorizontal = SizeFlags.FillExpand,
-            };
-
            _buttonContainer = new VBoxContainer()
            {
-                SizeFlagsVertical = SizeFlags.FillExpand,
-                SizeFlagsHorizontal = SizeFlags.Fill,
+                VerticalExpand = true,
                SeparationOverride = 5,

            };

            var scrollBarContainer = new ScrollContainer()
            {
-                SizeFlagsVertical = SizeFlags.FillExpand,
-                SizeFlagsHorizontal = SizeFlags.FillExpand
+                VerticalExpand = true,
+                HorizontalExpand = true
            };

-            margin.AddChild(scrollBarContainer);
            scrollBarContainer.AddChild(_buttonContainer);

-            Contents.AddChild(margin);
+            Contents.AddChild(scrollBarContainer);
        }

        public void Populate()
@@ -107,10 +99,10 @@ namespace Content.Client.UserInterface
                {
                    Text = value,
                    TextAlign = Label.AlignMode.Right,
-                    SizeFlagsHorizontal = SizeFlags.ShrinkCenter,
-                    SizeFlagsVertical = SizeFlags.ShrinkCenter,
+                    HorizontalAlignment = HAlignment.Center,
+                    VerticalAlignment = VAlignment.Center,
                    SizeFlagsStretchRatio = 1,
-                    CustomMinimumSize = (230, 20),
+                    MinSize = (230, 20),
                    ClipText = true,
                };

@@ -131,10 +123,10 @@ namespace Content.Client.UserInterface
                {
                    Text = $"Warp: {name}",
                    TextAlign = Label.AlignMode.Right,
-                    SizeFlagsHorizontal = SizeFlags.ShrinkCenter,
-                    SizeFlagsVertical = SizeFlags.ShrinkCenter,
+                    HorizontalAlignment = HAlignment.Center,
+                    VerticalAlignment = VAlignment.Center,
                    SizeFlagsStretchRatio = 1,
-                    CustomMinimumSize = (230,20),
+                    MinSize = (230,20),
                    ClipText = true,
                };

--- a/Content.Client/UserInterface/HumanoidProfileEditor.cs
+++ b/Content.Client/UserInterface/HumanoidProfileEditor.cs
@@ -63,7 +63,8 @@ namespace Content.Client.UserInterface
        public HumanoidCharacterProfile Profile;
        public event Action<HumanoidCharacterProfile> OnProfileChanged;

-        public HumanoidProfileEditor(IClientPreferencesManager preferencesManager, IPrototypeManager prototypeManager, IEntityManager entityManager)
+        public HumanoidProfileEditor(IClientPreferencesManager preferencesManager, IPrototypeManager prototypeManager,
+            IEntityManager entityManager)
        {
            _random = IoCManager.Resolve<IRobustRandom>();
            _prototypeManager = prototypeManager;
@@ -74,17 +75,9 @@ namespace Content.Client.UserInterface
            AddChild(hbox);

            #region Left
-            var margin = new MarginContainer
-            {
-                MarginTopOverride = 10,
-                MarginBottomOverride = 10,
-                MarginLeftOverride = 10,
-                MarginRightOverride = 10
-            };
-            hbox.AddChild(margin);

-            var vBox = new VBoxContainer();
-            margin.AddChild(vBox);
+            var vBox = new VBoxContainer {Margin = new Thickness(10)};
+            hbox.AddChild(vBox);

            var middleContainer = new HBoxContainer
            {
@@ -116,13 +109,13 @@ namespace Content.Client.UserInterface
                var panel = HighlightedContainer();
                var hBox = new HBoxContainer
                {
-                    SizeFlagsVertical = SizeFlags.FillExpand
+                    VerticalExpand = true
                };
-                var nameLabel = new Label { Text = Loc.GetString("Name:") };
+                var nameLabel = new Label {Text = Loc.GetString("Name:")};
                _nameEdit = new LineEdit
                {
-                    CustomMinimumSize = (270, 0),
-                    SizeFlagsVertical = SizeFlags.ShrinkCenter
+                    MinSize = (270, 0),
+                    VerticalAlignment = VAlignment.Center
                };
                _nameEdit.OnTextChanged += args => { SetName(args.Text); };
                var nameRandomButton = new Button
@@ -139,7 +132,7 @@ namespace Content.Client.UserInterface

            #endregion Name

-            var tabContainer = new TabContainer { SizeFlagsVertical = SizeFlags.FillExpand };
+            var tabContainer = new TabContainer {VerticalExpand = true};
            vBox.AddChild(tabContainer);

            #region Appearance
@@ -161,7 +154,7 @@ namespace Content.Client.UserInterface
                {
                    var panel = HighlightedContainer();
                    var hBox = new HBoxContainer();
-                    var sexLabel = new Label { Text = Loc.GetString("Sex:") };
+                    var sexLabel = new Label {Text = Loc.GetString("Sex:")};

                    var sexButtonGroup = new ButtonGroup();

@@ -209,8 +202,8 @@ namespace Content.Client.UserInterface
                {
                    var panel = HighlightedContainer();
                    var hBox = new HBoxContainer();
-                    var ageLabel = new Label { Text = Loc.GetString("Age:") };
-                    _ageEdit = new LineEdit { CustomMinimumSize = (40, 0) };
+                    var ageLabel = new Label {Text = Loc.GetString("Age:")};
+                    _ageEdit = new LineEdit {MinSize = (40, 0)};
                    _ageEdit.OnTextChanged += args =>
                    {
                        if (!int.TryParse(args.Text, out var newAge))
@@ -230,7 +223,7 @@ namespace Content.Client.UserInterface
                {
                    var panel = HighlightedContainer();
                    var hBox = new HBoxContainer();
-                    var genderLabel = new Label { Text = Loc.GetString("Pronouns:") };
+                    var genderLabel = new Label {Text = Loc.GetString("Pronouns:")};

                    _genderButton = new OptionButton();

@@ -257,7 +250,7 @@ namespace Content.Client.UserInterface

                {
                    var panel = HighlightedContainer();
-                    panel.SizeFlagsHorizontal = SizeFlags.None;
+                    panel.HorizontalAlignment = HAlignment.Left;
                    var hairHBox = new HBoxContainer();

                    _hairPicker = new HairStylePicker();
@@ -316,7 +309,7 @@ namespace Content.Client.UserInterface
                {
                    var panel = HighlightedContainer();
                    var hBox = new HBoxContainer();
-                    var clothingLabel = new Label { Text = Loc.GetString("Clothing:") };
+                    var clothingLabel = new Label {Text = Loc.GetString("Clothing:")};

                    _clothingButton = new OptionButton();

@@ -342,7 +335,7 @@ namespace Content.Client.UserInterface
                {
                    var panel = HighlightedContainer();
                    var hBox = new HBoxContainer();
-                    var backpackLabel = new Label { Text = Loc.GetString("Backpack:") };
+                    var backpackLabel = new Label {Text = Loc.GetString("Backpack:")};

                    _backpackButton = new OptionButton();

@@ -379,7 +372,7 @@ namespace Content.Client.UserInterface
                        (_preferenceUnavailableButton = new OptionButton()),
                        new ScrollContainer
                        {
-                            SizeFlagsVertical = SizeFlags.FillExpand,
+                            VerticalExpand = true,
                            Children =
                            {
                                jobList
@@ -433,7 +426,7 @@ namespace Content.Client.UserInterface
                            {
                                category.AddChild(new Control
                                {
-                                    CustomMinimumSize = new Vector2(0, 23),
+                                    MinSize = new Vector2(0, 23),
                                });
                            }

@@ -498,7 +491,7 @@ namespace Content.Client.UserInterface
                    {
                        new ScrollContainer
                        {
-                            SizeFlagsVertical = SizeFlags.FillExpand,
+                            VerticalExpand = true,
                            Children =
                            {
                                antagList
@@ -519,6 +512,7 @@ namespace Content.Client.UserInterface
                    {
                        continue;
                    }
+
                    var selector = new AntagPreferenceSelector(antag);
                    antagList.AddChild(selector);
                    _antagPreferences.Add(selector);
@@ -568,7 +562,7 @@ namespace Content.Client.UserInterface
                _saveButton = new Button
                {
                    Text = Loc.GetString("Save"),
-                    SizeFlagsHorizontal = SizeFlags.ShrinkCenter
+                    HorizontalAlignment = HAlignment.Center
                };
                _saveButton.OnPressed += args => { Save(); };
                panel.AddChild(_saveButton);
@@ -581,19 +575,10 @@ namespace Content.Client.UserInterface

            #region Right

-            margin = new MarginContainer
-            {
-                MarginTopOverride = 10,
-                MarginBottomOverride = 10,
-                MarginLeftOverride = 10,
-                MarginRightOverride = 10
-            };
-            hbox.AddChild(margin);
-
            vBox = new VBoxContainer()
            {
-                SizeFlagsVertical = SizeFlags.FillExpand,
-                SizeFlagsHorizontal = SizeFlags.FillExpand,
+                VerticalExpand = true,
+                HorizontalExpand = true,
            };
            hbox.AddChild(vBox);

@@ -605,8 +590,7 @@ namespace Content.Client.UserInterface
            // Front
            var box = new Control()
            {
-                SizeFlagsHorizontal = SizeFlags.Fill,
-                SizeFlagsVertical = SizeFlags.FillExpand,
+                VerticalExpand = true,
                SizeFlagsStretchRatio = 1f,
            };
            vBox.AddChild(box);
@@ -615,7 +599,7 @@ namespace Content.Client.UserInterface
                Sprite = sprite,
                Scale = (6, 6),
                OverrideDirection = Direction.South,
-                SizeFlagsVertical = SizeFlags.ShrinkCenter,
+                VerticalAlignment = VAlignment.Center,
                SizeFlagsStretchRatio = 1
            };
            box.AddChild(_previewSprite);
@@ -623,8 +607,7 @@ namespace Content.Client.UserInterface
            // Side
            box = new Control()
            {
-                SizeFlagsHorizontal = SizeFlags.Fill,
-                SizeFlagsVertical = SizeFlags.FillExpand,
+                VerticalExpand = true,
                SizeFlagsStretchRatio = 1f,
            };
            vBox.AddChild(box);
@@ -633,7 +616,7 @@ namespace Content.Client.UserInterface
                Sprite = sprite,
                Scale = (6, 6),
                OverrideDirection = Direction.East,
-                SizeFlagsVertical = SizeFlags.ShrinkCenter,
+                VerticalAlignment = VAlignment.Center,
                SizeFlagsStretchRatio = 1
            };
            box.AddChild(_previewSpriteSide);
@@ -862,7 +845,8 @@ namespace Content.Client.UserInterface

                if (job.Icon != null)
                {
-                    var specifier = new SpriteSpecifier.Rsi(new ResourcePath("/Textures/Interface/Misc/job_icons.rsi"), job.Icon);
+                    var specifier = new SpriteSpecifier.Rsi(new ResourcePath("/Textures/Interface/Misc/job_icons.rsi"),
+                        job.Icon);
                    icon.Texture = specifier.Frame0();
                }

@@ -871,7 +855,7 @@ namespace Content.Client.UserInterface
                    Children =
                    {
                        icon,
-                        new Label {Text = job.Name, CustomMinimumSize = (175, 0)},
+                        new Label {Text = job.Name, MinSize = (175, 0)},
                        _optionButton
                    }
                });
@@ -918,6 +902,7 @@ namespace Content.Client.UserInterface
                    }
                });
            }
+
            private void OnCheckBoxToggled(BaseButton.ButtonToggledEventArgs args)
            {
                PreferenceChanged?.Invoke(Preference);
--- a/Content.Client/UserInterface/ItemSlotButton.cs
+++ b/Content.Client/UserInterface/ItemSlotButton.cs
@@ -8,7 +8,7 @@ using Robust.Shared.Maths;

 namespace Content.Client.UserInterface
 {
-    public class ItemSlotButton : MarginContainer
+    public class ItemSlotButton : Control
    {
        private const string HighlightShader = "SelectionOutlineInrange";

@@ -29,7 +29,7 @@ namespace Content.Client.UserInterface

        public ItemSlotButton(Texture texture, Texture storageTexture)
        {
-            CustomMinimumSize = (64, 64);
+            MinSize = (64, 64);

            AddChild(Button = new TextureRect
            {
@@ -41,7 +41,7 @@ namespace Content.Client.UserInterface
            AddChild(_highlightRect = new PanelContainer
            {
                StyleClasses = { StyleNano.StyleClassHandSlotHighlight },
-                CustomMinimumSize = (32, 32),
+                MinSize = (32, 32),
                Visible = false
            });

@@ -63,8 +63,8 @@ namespace Content.Client.UserInterface
            {
                TextureNormal = storageTexture,
                Scale = (0.75f, 0.75f),
-                SizeFlagsHorizontal = SizeFlags.ShrinkEnd,
-                SizeFlagsVertical = SizeFlags.ShrinkEnd,
+                HorizontalAlignment = HAlignment.Right,
+                VerticalAlignment = VAlignment.Bottom,
                Visible = false,
            });

@@ -92,8 +92,6 @@ namespace Content.Client.UserInterface

            AddChild(CooldownDisplay = new CooldownGraphic
            {
-                SizeFlagsHorizontal = SizeFlags.Fill,
-                SizeFlagsVertical = SizeFlags.Fill,
                Visible = false,
            });
        }
--- a/Content.Client/UserInterface/ItemStatusPanel.cs
+++ b/Content.Client/UserInterface/ItemStatusPanel.cs
@@ -64,7 +64,10 @@ namespace Content.Client.UserInterface
                    }
                }
            });
-            SizeFlagsVertical = SizeFlags.ShrinkEnd;
+            VerticalAlignment = VAlignment.Bottom;
+
+            // TODO: Depending on if its a two-hand panel or not
+            MinSize = (150, 0);
        }

        /// <summary>
@@ -156,11 +159,5 @@ namespace Content.Client.UserInterface
                _activeStatusComponents.Add((statusComponent, control));
            }
        }
-
-        // TODO: Depending on if its a two-hand panel or not
-        protected override Vector2 CalculateMinimumSize()
-        {
-            return Vector2.ComponentMax(base.CalculateMinimumSize(), (150, 0));
-        }
    }
 }
--- a/Content.Client/UserInterface/LateJoinGui.cs
+++ b/Content.Client/UserInterface/LateJoinGui.cs
@@ -24,8 +24,6 @@ namespace Content.Client.UserInterface
        [Dependency] private readonly IClientConsoleHost _consoleHost = default!;
        [Dependency] private readonly IClientGameTicker _gameTicker = default!;

-        protected override Vector2? CustomSize => (360, 560);
-
        public event Action<string> SelectedId;

        private readonly Dictionary<string, JobButton> _jobButtons = new();
@@ -33,6 +31,7 @@ namespace Content.Client.UserInterface

        public LateJoinGui()
        {
+            MinSize = SetSize = (360, 560);
            IoCManager.InjectDependencies(this);

            Title = Loc.GetString("Late Join");
@@ -44,7 +43,7 @@ namespace Content.Client.UserInterface
                {
                    new ScrollContainer
                    {
-                        SizeFlagsVertical = SizeFlags.FillExpand,
+                        VerticalExpand = true,
                        Children =
                        {
                            jobList
@@ -77,7 +76,7 @@ namespace Content.Client.UserInterface
                        {
                            category.AddChild(new Control
                            {
-                                CustomMinimumSize = new Vector2(0, 23),
+                                MinSize = new Vector2(0, 23),
                            });
                        }

@@ -104,7 +103,7 @@ namespace Content.Client.UserInterface

                    var jobSelector = new HBoxContainer
                    {
-                        SizeFlagsHorizontal = SizeFlags.FillExpand
+                        HorizontalExpand = true
                    };

                    var icon = new TextureRect
--- a/Content.Client/UserInterface/LobbyCharacterPreviewPanel.cs
+++ b/Content.Client/UserInterface/LobbyCharacterPreviewPanel.cs
@@ -40,7 +40,7 @@ namespace Content.Client.UserInterface
            CharacterSetupButton = new Button
            {
                Text = Loc.GetString("Customize"),
-                SizeFlagsHorizontal = SizeFlags.None
+                HorizontalAlignment = HAlignment.Left
            };

            _summaryLabel = new Label();
--- a/Content.Client/UserInterface/LobbyGui.xaml
+++ b/Content.Client/UserInterface/LobbyGui.xaml
@@ -13,7 +13,7 @@
        <PanelContainer StyleClasses="AngleRect" />
        <VBoxContainer>
            <!-- Top row -->
-            <HBoxContainer CustomMinimumSize="0 40">
+            <HBoxContainer MinSize="0 40">
                <MarginContainer MarginLeftOverride="8">
                    <Label StyleClasses="LabelHeadingBigger" VAlign="Center" Text="{Loc 'Lobby'}" />
                </MarginContainer>
@@ -30,9 +30,9 @@
                </PanelContainer.PanelOverride>
            </PanelContainer>
            <!-- Middle section with the two vertical panels -->
-            <HBoxContainer SizeFlagsVertical="FillExpand">
+            <HBoxContainer VerticalExpand="True">
                <!-- Left panel -->
-                <VBoxContainer Name="CLeftPanelContainer" SizeFlagsHorizontal="FillExpand">
+                <VBoxContainer Name="CLeftPanelContainer" HorizontalExpand="True">
                    <cui:StripeBack>
                        <MarginContainer MarginLeftOverride="3" MarginRightOverride="3" MarginBottomOverride="3"
                                         MarginTopOverride="3">
@@ -40,39 +40,39 @@
                                <Button Name="CObserveButton" Text="{Loc 'Observe'}" StyleClasses="ButtonBig" />
                                <Label Name="CStartTime" Align="Right"
                                       FontColorOverride="{x:Static maths:Color.DarkGray}"
-                                       StyleClasses="LabelBig" SizeFlagsHorizontal="FillExpand" />
+                                       StyleClasses="LabelBig" HorizontalExpand="True" />
                                <Button Name="CReadyButton" ToggleMode="True" Text="{Loc 'Ready Up'}"
                                        StyleClasses="ButtonBig" />
                            </HBoxContainer>
                        </MarginContainer>
                    </cui:StripeBack>
-                    <MarginContainer SizeFlagsVertical="FillExpand" MarginLeftOverride="3" MarginRightOverride="3"
+                    <MarginContainer VerticalExpand="True" MarginLeftOverride="3" MarginRightOverride="3"
                                     MarginBottomOverride="3"
                                     MarginTopOverride="3">
                        <chat:ChatBox Name="CChat" />
                    </MarginContainer>
                </VBoxContainer>
                <!-- Gold line -->
-                <PanelContainer CustomMinimumSize="2 0">
+                <PanelContainer MinSize="2 0">
                    <PanelContainer.PanelOverride>
                        <gfx:StyleBoxFlat BackgroundColor="{x:Static style:StyleNano.NanoGold}" />
                    </PanelContainer.PanelOverride>
                </PanelContainer>
                <!-- Right panel -->
-                <Control SizeFlagsHorizontal="FillExpand">
+                <Control HorizontalExpand="True">
                    <VBoxContainer>
                        <!-- Player list -->
                        <cui:NanoHeading Text="{Loc 'Online Players'}" />
-                        <MarginContainer SizeFlagsVertical="FillExpand"
+                        <MarginContainer VerticalExpand="True"
                                         MarginRightOverride="3" MarginLeftOverride="3"
                                         MarginBottomOverride="3" MarginTopOverride="3">
                            <cui:LobbyPlayerList Name="COnlinePlayerList"
-                                                 SizeFlagsHorizontal="FillExpand"
-                                                 SizeFlagsVertical="FillExpand" />
+                                                 HorizontalExpand="True"
+                                                 VerticalExpand="True" />
                        </MarginContainer>
                        <!-- Server info -->
                        <cui:NanoHeading Text="{Loc 'Server Info'}" />
-                        <MarginContainer SizeFlagsVertical="FillExpand"
+                        <MarginContainer VerticalExpand="True"
                                         MarginRightOverride="3" MarginLeftOverride="3"
                                         MarginBottomOverride="2" MarginTopOverride="3">
                            <cui:ServerInfo Name="CServerInfo" />
--- a/Content.Client/UserInterface/LobbyGui.xaml.cs
+++ b/Content.Client/UserInterface/LobbyGui.xaml.cs
@@ -30,13 +30,14 @@ namespace Content.Client.UserInterface
        {
            RobustXamlLoader.Load(this);

-            ServerName.SizeFlagsHorizontal = SizeFlags.Expand | SizeFlags.ShrinkCenter;
+            ServerName.HorizontalExpand = true;
+            ServerName.HorizontalAlignment = HAlignment.Center;

            CharacterPreview = new LobbyCharacterPreviewPanel(
                entityManager,
                preferencesManager)
            {
-                SizeFlagsHorizontal = SizeFlags.None
+                HorizontalAlignment = HAlignment.Left
            };

            CLeftPanelContainer.AddChild(CharacterPreview);
@@ -67,7 +68,7 @@ namespace Content.Client.UserInterface
        {
            var hbox = new HBoxContainer
            {
-                SizeFlagsHorizontal = SizeFlags.FillExpand,
+                HorizontalExpand = true,
            };

            // Player Name
@@ -88,7 +89,7 @@ namespace Content.Client.UserInterface
                        Text = name
                    }
                },
-                SizeFlagsHorizontal = SizeFlags.FillExpand
+                HorizontalExpand = true
            });
            // Status
            hbox.AddChild(new PanelContainer()
@@ -108,7 +109,7 @@ namespace Content.Client.UserInterface
                        Text = status
                    }
                },
-                SizeFlagsHorizontal = SizeFlags.FillExpand,
+                HorizontalExpand = true,
                SizeFlagsStretchRatio = 0.2f,
            });

--- a/Content.Client/UserInterface/NanoHeading.cs
+++ b/Content.Client/UserInterface/NanoHeading.cs
@@ -20,7 +20,7 @@ namespace Content.Client.UserInterface
            };
            AddChild(_panel);

-            SizeFlagsHorizontal = SizeFlags.None;
+            HorizontalAlignment = HAlignment.Left;
        }

        public string Text
@@ -28,15 +28,5 @@ namespace Content.Client.UserInterface
            get => _label.Text;
            set => _label.Text = value;
        }
-
-        protected override Vector2 CalculateMinimumSize()
-        {
-            return _panel.CombinedMinimumSize;
-        }
-
-        protected override void LayoutUpdateOverride()
-        {
-            FitChildInBox(_panel, SizeBox);
-        }
    }
 }
--- a/Content.Client/UserInterface/OptionsMenu.Audio.cs
+++ b/Content.Client/UserInterface/OptionsMenu.Audio.cs
@@ -5,6 +5,7 @@ using Robust.Client.UserInterface.Controls;
 using Robust.Shared;
 using Robust.Shared.Configuration;
 using Robust.Shared.Localization;
+using Robust.Shared.Maths;

 namespace Content.Client.UserInterface
 {
@@ -27,20 +28,24 @@ namespace Content.Client.UserInterface

                var vBox = new VBoxContainer();

-                var contents = new VBoxContainer();
+                var contents = new VBoxContainer
+                {
+                    Margin = new Thickness(2, 2, 2, 0),
+                    VerticalExpand = true,
+                };

                MasterVolumeSlider = new Slider
                {
                    MinValue = 0.0f,
                    MaxValue = 100.0f,
-                    SizeFlagsHorizontal = SizeFlags.FillExpand,
-                    CustomMinimumSize = (80, 8),
+                    HorizontalExpand = true,
+                    MinSize = (80, 8),
                    Rounded = true
                };

                MasterVolumeLabel = new Label
                {
-                    CustomMinimumSize = (48, 0),
+                    MinSize = (48, 0),
                    Align = Label.AlignMode.Right
                };

@@ -48,20 +53,20 @@ namespace Content.Client.UserInterface
                {
                    Children =
                    {
-                        new Control {CustomMinimumSize = (4, 0)},
+                        new Control {MinSize = (4, 0)},
                        new Label {Text = Loc.GetString("Master Volume:")},
-                        new Control {CustomMinimumSize = (8, 0)},
+                        new Control {MinSize = (8, 0)},
                        MasterVolumeSlider,
-                        new Control {CustomMinimumSize = (8, 0)},
+                        new Control {MinSize = (8, 0)},
                        MasterVolumeLabel,
-                        new Control { CustomMinimumSize = (4, 0) },
+                        new Control { MinSize = (4, 0) },
                    }
                });

                ApplyButton = new Button
                {
                    Text = Loc.GetString("Apply"), TextAlign = Label.AlignMode.Center,
-                    SizeFlagsHorizontal = SizeFlags.ShrinkEnd
+                    HorizontalAlignment = HAlignment.Right
                };

                vBox.AddChild(new Label
@@ -71,23 +76,13 @@ namespace Content.Client.UserInterface
                    StyleClasses = { StyleNano.StyleClassLabelKeyText }
                });

-                vBox.AddChild(new MarginContainer
-                {
-                    MarginLeftOverride = 2,
-                    MarginTopOverride = 2,
-                    MarginRightOverride = 2,
-                    SizeFlagsVertical = SizeFlags.FillExpand,
-                    Children =
-                    {
-                        contents
-                    }
-                });
+                vBox.AddChild(contents);

                ResetButton = new Button
                {
                    Text = Loc.GetString("Reset all"),
                    StyleClasses = { StyleBase.ButtonCaution },
-                    SizeFlagsHorizontal = SizeFlags.ShrinkEnd
+                    HorizontalAlignment = HAlignment.Right
                };

                vBox.AddChild(new StripeBack
@@ -99,12 +94,12 @@ namespace Content.Client.UserInterface
                        new HBoxContainer
                        {
                            Align = BoxContainer.AlignMode.End,
-                            SizeFlagsHorizontal = SizeFlags.FillExpand,
-                            SizeFlagsVertical = SizeFlags.FillExpand,
+                            HorizontalExpand = true,
+                            VerticalExpand = true,
                            Children =
                            {
                                ResetButton,
-                                new Control { CustomMinimumSize = (2, 0) },
+                                new Control { MinSize = (2, 0) },
                                ApplyButton
                            }
                        }
--- a/Content.Client/UserInterface/OptionsMenu.Graphics.cs
+++ b/Content.Client/UserInterface/OptionsMenu.Graphics.cs
@@ -38,7 +38,11 @@ namespace Content.Client.UserInterface
                _cfg = cfg;
                var vBox = new VBoxContainer();

-                var contents = new VBoxContainer();
+                var contents = new VBoxContainer
+                {
+                    Margin = new Thickness(2, 2, 2, 0),
+                    VerticalExpand = true,
+                };

                VSyncCheckBox = new CheckBox {Text = Loc.GetString("VSync")};
                contents.AddChild(VSyncCheckBox);
@@ -48,7 +52,7 @@ namespace Content.Client.UserInterface
                contents.AddChild(FullscreenCheckBox);
                FullscreenCheckBox.OnToggled += OnCheckBoxToggled;

-                LightingPresetOption = new OptionButton {CustomMinimumSize = (100, 0)};
+                LightingPresetOption = new OptionButton {MinSize = (100, 0)};
                LightingPresetOption.AddItem(Loc.GetString("Very Low"));
                LightingPresetOption.AddItem(Loc.GetString("Low"));
                LightingPresetOption.AddItem(Loc.GetString("Medium"));
@@ -60,7 +64,7 @@ namespace Content.Client.UserInterface
                    Children =
                    {
                        new Label {Text = Loc.GetString("Lighting Quality:")},
-                        new Control {CustomMinimumSize = (4, 0)},
+                        new Control {MinSize = (4, 0)},
                        LightingPresetOption
                    }
                });
@@ -68,7 +72,7 @@ namespace Content.Client.UserInterface
                ApplyButton = new Button
                {
                    Text = Loc.GetString("Apply"), TextAlign = Label.AlignMode.Center,
-                    SizeFlagsHorizontal = SizeFlags.ShrinkEnd
+                    HorizontalAlignment = HAlignment.Right
                };

                var resourceCache = IoCManager.Resolve<IResourceCache>();
@@ -88,28 +92,18 @@ namespace Content.Client.UserInterface
                    Children =
                    {
                        new Label {Text = Loc.GetString("UI Scale:")},
-                        new Control {CustomMinimumSize = (4, 0)},
+                        new Control {MinSize = (4, 0)},
                        _uiScaleOption
                    }
                });

                contents.AddChild(new Placeholder(resourceCache)
                {
-                    SizeFlagsVertical = SizeFlags.FillExpand,
+                    VerticalExpand = true,
                    PlaceholderText = "Viewport settings"
                });

-                vBox.AddChild(new MarginContainer
-                {
-                    MarginLeftOverride = 2,
-                    MarginTopOverride = 2,
-                    MarginRightOverride = 2,
-                    SizeFlagsVertical = SizeFlags.FillExpand,
-                    Children =
-                    {
-                        contents
-                    }
-                });
+                vBox.AddChild(contents);

                vBox.AddChild(new StripeBack
                {
--- a/Content.Client/UserInterface/OptionsMenu.KeyRebind.cs
+++ b/Content.Client/UserInterface/OptionsMenu.KeyRebind.cs
@@ -9,6 +9,7 @@ using Robust.Client.UserInterface.Controls;
 using Robust.Shared.Input;
 using Robust.Shared.IoC;
 using Robust.Shared.Localization;
+using Robust.Shared.Maths;
 using Robust.Shared.Timing;
 using Robust.Shared.Utility;

@@ -39,25 +40,15 @@ namespace Content.Client.UserInterface
                IoCManager.InjectDependencies(this);

                Button resetAllButton;
-                var vBox = new VBoxContainer();
+                var vBox = new VBoxContainer {Margin = new Thickness(2, 0, 0, 0)};
                AddChild(new VBoxContainer
                {
                    Children =
                    {
                        new ScrollContainer
                        {
-                            SizeFlagsVertical = SizeFlags.FillExpand,
-                            Children =
-                            {
-                                new MarginContainer
-                                {
-                                    MarginLeftOverride = 2,
-                                    Children =
-                                    {
-                                        vBox
-                                    }
-                                }
-                            }
+                            VerticalExpand = true,
+                            Children = {vBox}
                        },

                        new StripeBack
@@ -70,7 +61,7 @@ namespace Content.Client.UserInterface
                                {
                                    Children =
                                    {
-                                        new Control {CustomMinimumSize = (2, 0)},
+                                        new Control {MinSize = (2, 0)},
                                        new Label
                                        {
                                            StyleClasses = {StyleBase.StyleClassLabelSubText},
@@ -80,7 +71,7 @@ namespace Content.Client.UserInterface
                                        {
                                            Text = "Reset ALL keybinds",
                                            StyleClasses = {StyleBase.ButtonCaution},
-                                            SizeFlagsHorizontal = SizeFlags.ShrinkEnd | SizeFlags.Expand
+                                            HorizontalAlignment = HAlignment.Right
                                        })
                                    }
                                }
@@ -89,7 +80,7 @@ namespace Content.Client.UserInterface
                    }
                });

-                resetAllButton.OnPressed += args =>
+                resetAllButton.OnPressed += _ =>
                {
                    _deferCommands.Add(() =>
                    {
@@ -104,7 +95,7 @@ namespace Content.Client.UserInterface
                {
                    if (!first)
                    {
-                        vBox.AddChild(new Control {CustomMinimumSize = (0, 8)});
+                        vBox.AddChild(new Control {MinSize = (0, 8)});
                    }

                    first = false;
@@ -409,22 +400,23 @@ namespace Content.Client.UserInterface
                    var name = new Label
                    {
                        Text = Loc.GetString(niceName),
-                        SizeFlagsHorizontal = SizeFlags.Expand
+                        HorizontalExpand = true,
+                        HorizontalAlignment = HAlignment.Left
                    };

                    BindButton1 = new BindButton(parent, this, StyleBase.ButtonOpenRight);
                    BindButton2 = new BindButton(parent, this, StyleBase.ButtonOpenLeft);
-                    ResetButton = new Button {Text = "Reset", StyleClasses = {StyleBase.ButtonCaution}};
+                    ResetButton = new Button {Text = Loc.GetString("Reset"), StyleClasses = {StyleBase.ButtonCaution}};

                    var hBox = new HBoxContainer
                    {
                        Children =
                        {
-                            new Control {CustomMinimumSize = (5, 0)},
+                            new Control {MinSize = (5, 0)},
                            name,
                            BindButton1,
                            BindButton2,
-                            new Control {CustomMinimumSize = (10, 0)},
+                            new Control {MinSize = (10, 0)},
                            ResetButton
                        }
                    };
@@ -464,7 +456,7 @@ namespace Content.Client.UserInterface

                    Button.OnKeyBindDown += ButtonOnOnKeyBindDown;

-                    CustomMinimumSize = (200, 0);
+                    MinSize = (200, 0);
                }

                private void ButtonOnOnKeyBindDown(GUIBoundKeyEventArgs args)
--- a/Content.Client/UserInterface/OptionsMenu.cs
+++ b/Content.Client/UserInterface/OptionsMenu.cs
@@ -15,10 +15,9 @@ namespace Content.Client.UserInterface
        [Dependency] private readonly IConfigurationManager _configManager = default!;
        [Dependency] private readonly IClydeAudio _clydeAudio = default!;

-        protected override Vector2? CustomSize => (800, 450);
-
        public OptionsMenu()
        {
+            SetSize = MinSize = (800, 450);
            IoCManager.InjectDependencies(this);

            Title = Loc.GetString("Game Options");
--- a/Content.Client/UserInterface/ParticleAccelerator/ParticleAcceleratorControlMenu.cs
+++ b/Content.Client/UserInterface/ParticleAccelerator/ParticleAcceleratorControlMenu.cs
@@ -53,6 +53,7 @@ namespace Content.Client.ParticleAccelerator

        public ParticleAcceleratorControlMenu(ParticleAcceleratorBoundUserInterface owner)
        {
+            SetSize = (400, 300);
            _greyScaleShader = IoCManager.Resolve<IPrototypeManager>().Index<ShaderPrototype>("Greyscale").Instance();

            Owner = owner;
@@ -128,13 +129,14 @@ namespace Content.Client.ParticleAccelerator
            var closeButton = new TextureButton
            {
                StyleClasses = {"windowCloseButton"},
-                SizeFlagsHorizontal = SizeFlags.ShrinkEnd
+                HorizontalAlignment = HAlignment.Right,
+                Margin = new Thickness(0, 0, 8, 0)
            };
            closeButton.OnPressed += args => Close();

            var serviceManual = new Label
            {
-                SizeFlagsHorizontal = SizeFlags.ShrinkCenter,
+                HorizontalAlignment = HAlignment.Center,
                StyleClasses = {StyleBase.StyleClassLabelSubText},
                Text = Loc.GetString("Refer to p.132 of service manual")
            };
@@ -144,10 +146,9 @@ namespace Content.Client.ParticleAccelerator
            {
                Children =
                {
-                    new MarginContainer
+                    new Control
                    {
-                        MarginLeftOverride = 2,
-                        MarginTopOverride = 2,
+                        Margin = new Thickness(2, 2, 0, 0),
                        Children =
                        {
                            new Label
@@ -156,185 +157,154 @@ namespace Content.Client.ParticleAccelerator
                                FontOverride = font,
                                FontColorOverride = StyleNano.NanoGold,
                            },
-                            new MarginContainer
-                            {
-                                MarginRightOverride = 8,
-                                Children =
-                                {
-                                    closeButton
-                                }
-                            }
+                            closeButton
                        }
                    },
                    new PanelContainer
                    {
                        PanelOverride = new StyleBoxFlat {BackgroundColor = StyleNano.NanoGold},
-                        CustomMinimumSize = (0, 2),
+                        MinSize = (0, 2),
                    },
                    new Control
                    {
-                        CustomMinimumSize = (0, 4)
+                        MinSize = (0, 4)
                    },

                    new HBoxContainer
                    {
-                        SizeFlagsVertical = SizeFlags.FillExpand,
+                        VerticalExpand = true,
                        Children =
                        {
-                            new MarginContainer
+                            new VBoxContainer
                            {
-                                MarginLeftOverride = 4,
-                                SizeFlagsHorizontal = SizeFlags.FillExpand,
+                                Margin = new Thickness(4, 0, 0, 0),
+                                HorizontalExpand = true,
                                Children =
                                {
-                                    new VBoxContainer
+                                    new HBoxContainer
                                    {
                                        Children =
                                        {
-                                            new HBoxContainer
+                                            new Label
                                            {
-                                                Children =
-                                                {
-                                                    new Label
-                                                    {
-                                                        Text = Loc.GetString("Power: "),
-                                                        SizeFlagsHorizontal = SizeFlags.Expand
-                                                    },
-                                                    _offButton,
-                                                    _onButton
-                                                }
+                                                Text = Loc.GetString("Power: "),
+                                                HorizontalExpand = true,
+                                                HorizontalAlignment = HAlignment.Left,
                                            },
-                                            new HBoxContainer
-                                            {
-                                                Children =
-                                                {
-                                                    new Label
-                                                    {
-                                                        Text = Loc.GetString("Strength: "),
-                                                        SizeFlagsHorizontal = SizeFlags.Expand
-                                                    },
-                                                    _stateSpinBox
-                                                }
-                                            },
-                                            new Control
-                                            {
-                                                CustomMinimumSize = (0, 10),
-                                            },
-                                            _drawLabel,
-                                            new Control
-                                            {
-                                                SizeFlagsVertical = SizeFlags.Expand
-                                            },
-                                            (_alarmControl = new VBoxContainer
-                                            {
-                                                Children =
-                                                {
-                                                    new Label
-                                                    {
-                                                        Text = Loc.GetString("PARTICLE STRENGTH\nLIMITER FAILURE"),
-                                                        FontColorOverride = Color.Red,
-                                                        Align = Label.AlignMode.Center
-                                                    },
-                                                    serviceManual
-                                                }
-                                            }),
+                                            _offButton,
+                                            _onButton
                                        }
-                                    }
-                                }
-                            },
-                            new MarginContainer
-                            {
-                                CustomMinimumSize = (186, 0),
-                                Children =
-                                {
-                                    new VBoxContainer
+                                    },
+                                    new HBoxContainer
                                    {
                                        Children =
                                        {
-                                            (_statusLabel = new Label
+                                            new Label
                                            {
-                                                SizeFlagsHorizontal = SizeFlags.ShrinkCenter
-                                            }),
-                                            new Control
-                                            {
-                                                CustomMinimumSize = (0, 20)
+                                                Text = Loc.GetString("Strength: "),
+                                                HorizontalExpand = true,
+                                                HorizontalAlignment = HAlignment.Left,
                                            },
-                                            new PanelContainer
-                                            {
-                                                SizeFlagsHorizontal = SizeFlags.ShrinkCenter,
-                                                PanelOverride = back2,
-                                                Children =
-                                                {
-                                                    new GridContainer
-                                                    {
-                                                        Columns = 3,
-                                                        VSeparationOverride = 0,
-                                                        HSeparationOverride = 0,
-                                                        Children =
-                                                        {
-                                                            new Control {CustomMinimumSize = imgSize},
-                                                            (_endCapTexture = Segment("end_cap")),
-                                                            new Control {CustomMinimumSize = imgSize},
-                                                            (_controlBoxTexture = Segment("control_box")),
-                                                            (_fuelChamberTexture = Segment("fuel_chamber")),
-                                                            new Control {CustomMinimumSize = imgSize},
-                                                            new Control {CustomMinimumSize = imgSize},
-                                                            (_powerBoxTexture = Segment("power_box")),
-                                                            new Control {CustomMinimumSize = imgSize},
-                                                            (_emitterLeftTexture = Segment("emitter_left")),
-                                                            (_emitterCenterTexture = Segment("emitter_center")),
-                                                            (_emitterRightTexture = Segment("emitter_right")),
-                                                        }
-                                                    }
-                                                }
-                                            },
-                                            (_scanButton = new Button
-                                            {
-                                                Text = Loc.GetString("Scan Parts"),
-                                                SizeFlagsHorizontal = SizeFlags.ShrinkCenter
-                                            })
+                                            _stateSpinBox
                                        }
-                                    }
+                                    },
+                                    new Control
+                                    {
+                                        MinSize = (0, 10),
+                                    },
+                                    _drawLabel,
+                                    new Control
+                                    {
+                                        VerticalExpand = true,
+                                    },
+                                    (_alarmControl = new VBoxContainer
+                                    {
+                                        Children =
+                                        {
+                                            new Label
+                                            {
+                                                Text = Loc.GetString("PARTICLE STRENGTH\nLIMITER FAILURE"),
+                                                FontColorOverride = Color.Red,
+                                                Align = Label.AlignMode.Center
+                                            },
+                                            serviceManual
+                                        }
+                                    }),
                                }
                            },
+                            new VBoxContainer
+                            {
+                                MinSize = (186, 0),
+                                Children =
+                                {
+                                    (_statusLabel = new Label
+                                    {
+                                        HorizontalAlignment = HAlignment.Center
+                                    }),
+                                    new Control
+                                    {
+                                        MinSize = (0, 20)
+                                    },
+                                    new PanelContainer
+                                    {
+                                        HorizontalAlignment = HAlignment.Center,
+                                        PanelOverride = back2,
+                                        Children =
+                                        {
+                                            new GridContainer
+                                            {
+                                                Columns = 3,
+                                                VSeparationOverride = 0,
+                                                HSeparationOverride = 0,
+                                                Children =
+                                                {
+                                                    new Control {MinSize = imgSize},
+                                                    (_endCapTexture = Segment("end_cap")),
+                                                    new Control {MinSize = imgSize},
+                                                    (_controlBoxTexture = Segment("control_box")),
+                                                    (_fuelChamberTexture = Segment("fuel_chamber")),
+                                                    new Control {MinSize = imgSize},
+                                                    new Control {MinSize = imgSize},
+                                                    (_powerBoxTexture = Segment("power_box")),
+                                                    new Control {MinSize = imgSize},
+                                                    (_emitterLeftTexture = Segment("emitter_left")),
+                                                    (_emitterCenterTexture = Segment("emitter_center")),
+                                                    (_emitterRightTexture = Segment("emitter_right")),
+                                                }
+                                            }
+                                        }
+                                    },
+                                    (_scanButton = new Button
+                                    {
+                                        Text = Loc.GetString("Scan Parts"),
+                                        HorizontalAlignment = HAlignment.Center
+                                    })
+                                }
+                            }
                        }
                    },
                    new StripeBack
                    {
                        Children =
                        {
-                            new MarginContainer
+                            new Label
                            {
-                                MarginLeftOverride = 4,
-                                MarginTopOverride = 4,
-                                MarginBottomOverride = 4,
-                                Children =
-                                {
-                                    new Label
-                                    {
-                                        Text = Loc.GetString("Ensure containment field is active before operation"),
-                                        SizeFlagsHorizontal = SizeFlags.ShrinkCenter,
-                                        StyleClasses = {StyleBase.StyleClassLabelSubText},
-                                    }
-                                }
+                                Margin = new Thickness(4, 4, 0, 4),
+                                Text = Loc.GetString("Ensure containment field is active before operation"),
+                                HorizontalAlignment = HAlignment.Center,
+                                StyleClasses = {StyleBase.StyleClassLabelSubText},
                            }
                        }
                    },
-                    new MarginContainer
+                    new HBoxContainer
                    {
-                        MarginLeftOverride = 12,
+                        Margin = new Thickness(12, 0, 0, 0),
                        Children =
                        {
-                            new HBoxContainer
+                            new Label
                            {
-                                Children =
-                                {
-                                    new Label
-                                    {
-                                        Text = "FOO-BAR-BAZ",
-                                        StyleClasses = {StyleBase.StyleClassLabelSubText}
-                                    }
-                                }
+                                Text = "FOO-BAR-BAZ",
+                                StyleClasses = {StyleBase.StyleClassLabelSubText}
                            }
                        }
                    },
@@ -398,11 +368,6 @@ namespace Content.Client.ParticleAccelerator
            return DragMode.Move;
        }

-        protected override Vector2 CalculateMinimumSize()
-        {
-            return (400, 300);
-        }
-
        public void DataUpdate(ParticleAcceleratorUIState uiState)
        {
            _assembled = uiState.Assembled;
@@ -504,6 +469,7 @@ namespace Content.Client.ParticleAccelerator

                AddChild(_base = new TextureRect {Texture = _rsi[$"{name}c"].Frame0});
                AddChild(_unlit = new TextureRect());
+                MinSize = _rsi.Size;
            }

            public void SetPowerState(ParticleAcceleratorUIState state, bool exists)
@@ -537,11 +503,6 @@ namespace Content.Client.ParticleAccelerator

                _unlit.Texture = rState.Frame0;
            }
-
-            protected override Vector2 CalculateMinimumSize()
-            {
-                return _rsi.Size;
-            }
        }
    }
 }
--- a/Content.Client/UserInterface/Permissions/PermissionsEui.cs
+++ b/Content.Client/UserInterface/Permissions/PermissionsEui.cs
@@ -246,7 +246,8 @@ namespace Content.Client.UserInterface.Permissions
                al.AddChild(new Label
                {
                    Text = flagsText,
-                    SizeFlagsHorizontal = Control.SizeFlags.ShrinkCenter | Control.SizeFlags.Expand
+                    HorizontalExpand = true,
+                    HorizontalAlignment = Control.HAlignment.Center,
                });

                var editButton = new Button {Text = Loc.GetString("Edit")};
@@ -269,7 +270,8 @@ namespace Content.Client.UserInterface.Permissions
                _menu.AdminRanksList.AddChild(new Label
                {
                    Text = flagsText,
-                    SizeFlagsHorizontal = Control.SizeFlags.ShrinkCenter | Control.SizeFlags.Expand
+                    HorizontalExpand = true,
+                    HorizontalAlignment = Control.HAlignment.Center,
                });
                var editButton = new Button {Text = Loc.GetString("Edit")};
                editButton.OnPressed += _ => OnEditRankPressed(kv);
@@ -306,16 +308,16 @@ namespace Content.Client.UserInterface.Permissions
                AddAdminButton = new Button
                {
                    Text = Loc.GetString("Add Admin"),
-                    SizeFlagsHorizontal = SizeFlags.ShrinkEnd
+                    HorizontalAlignment = HAlignment.Right
                };

                AddAdminRankButton = new Button
                {
                    Text = Loc.GetString("Add Admin Rank"),
-                    SizeFlagsHorizontal = SizeFlags.ShrinkEnd
+                    HorizontalAlignment = HAlignment.Right
                };

-                AdminsList = new GridContainer {Columns = 5, SizeFlagsVertical = SizeFlags.FillExpand};
+                AdminsList = new GridContainer {Columns = 5, VerticalExpand = true};
                var adminVBox = new VBoxContainer
                {
                    Children = {AdminsList, AddAdminButton},
@@ -352,6 +354,7 @@ namespace Content.Client.UserInterface.Permissions

            public EditAdminWindow(PermissionsEui ui, PermissionsEuiState.AdminData? data)
            {
+                SetSize = MinSize = (600, 400);
                SourceData = data;

                Control nameControl;
@@ -372,7 +375,7 @@ namespace Content.Client.UserInterface.Permissions

                TitleEdit = new LineEdit {PlaceHolder = Loc.GetString("Custom title, leave blank to inherit rank title.")};
                RankButton = new OptionButton();
-                SaveButton = new Button {Text = Loc.GetString("Save"), SizeFlagsHorizontal = SizeFlags.ShrinkEnd | SizeFlags.Expand};
+                SaveButton = new Button {Text = Loc.GetString("Save"), HorizontalAlignment = HAlignment.Right};

                RankButton.AddItem(Loc.GetString("No rank"), NoRank);
                foreach (var (rId, rank) in ui._ranks)
@@ -470,7 +473,7 @@ namespace Content.Client.UserInterface.Permissions
                            {
                                new VBoxContainer
                                {
-                                    SizeFlagsHorizontal = SizeFlags.FillExpand,
+                                    HorizontalExpand = true,
                                    Children =
                                    {
                                        nameControl,
@@ -480,7 +483,7 @@ namespace Content.Client.UserInterface.Permissions
                                },
                                permGrid
                            },
-                            SizeFlagsVertical = SizeFlags.FillExpand
+                            VerticalExpand = true
                        },
                        bottomButtons
                    }
@@ -509,8 +512,6 @@ namespace Content.Client.UserInterface.Permissions
                    }
                }
            }
-
-            protected override Vector2? CustomSize => (600, 400);
        }

        private sealed class EditAdminRankWindow : SS14Window
@@ -523,6 +524,7 @@ namespace Content.Client.UserInterface.Permissions

            public EditAdminRankWindow(PermissionsEui ui, KeyValuePair<int, PermissionsEuiState.AdminRankData>? data)
            {
+                MinSize = SetSize = (600, 400);
                SourceId = data?.Key;

                NameEdit = new LineEdit
@@ -535,7 +537,11 @@ namespace Content.Client.UserInterface.Permissions
                    NameEdit.Text = data.Value.Value.Name;
                }

-                SaveButton = new Button {Text = Loc.GetString("Save"), SizeFlagsHorizontal = SizeFlags.ShrinkEnd | SizeFlags.Expand};
+                SaveButton = new Button {
+                    Text = Loc.GetString("Save"),
+                    HorizontalAlignment = HAlignment.Right,
+                    HorizontalExpand = true
+                };
                var flagsBox = new VBoxContainer();

                foreach (var flag in AdminFlagsHelper.AllFlags)
@@ -594,8 +600,6 @@ namespace Content.Client.UserInterface.Permissions

                return flags;
            }
-
-            protected override Vector2? CustomSize => (600, 400);
        }
    }
 }
--- a/Content.Client/UserInterface/Placeholder.cs
+++ b/Content.Client/UserInterface/Placeholder.cs
@@ -19,8 +19,7 @@ namespace Content.Client.UserInterface
        {
            _label = new Label
            {
-                SizeFlagsHorizontal = SizeFlags.Fill,
-                SizeFlagsVertical = SizeFlags.Fill,
+                VerticalAlignment = VAlignment.Stretch,
                Align = Label.AlignMode.Center,
                VAlign = Label.VAlignMode.Center
            };
--- a/Content.Client/UserInterface/RoundEndSummaryWindow.cs
+++ b/Content.Client/UserInterface/RoundEndSummaryWindow.cs
@@ -2,11 +2,9 @@
 using System.Collections.Generic;
 using System.Linq;
 using Content.Client.Utility;
-using Robust.Client.UserInterface;
 using Robust.Client.UserInterface.Controls;
 using Robust.Client.UserInterface.CustomControls;
 using Robust.Shared.Localization;
-using Robust.Shared.Maths;
 using static Content.Shared.GameTicking.SharedGameTicker;

 namespace Content.Client.UserInterface
@@ -16,10 +14,10 @@ namespace Content.Client.UserInterface
        private VBoxContainer RoundEndSummaryTab { get; }
        private VBoxContainer PlayerManifestoTab { get; }
        private TabContainer RoundEndWindowTabs { get; }
-        protected override Vector2? CustomSize => (520, 580);

        public RoundEndSummaryWindow(string gm, string roundEnd, TimeSpan roundTimeSpan, List<RoundEndPlayerInfo> info)
        {
+            MinSize = SetSize = (520, 580);

            Title = Loc.GetString("Round End Summary");

@@ -66,7 +64,7 @@ namespace Content.Client.UserInterface

            //Initialize what will be the list of players display.
            var scrollContainer = new ScrollContainer();
-            scrollContainer.SizeFlagsVertical = SizeFlags.FillExpand;
+            scrollContainer.VerticalExpand = true;
            var innerScrollContainer = new VBoxContainer();

            //Put observers at the bottom of the list. Put antags on top.
@@ -74,10 +72,7 @@ namespace Content.Client.UserInterface
            //Create labels for each player info.
            foreach (var playerInfo in manifestSortedList)
            {
-                var playerInfoText = new RichTextLabel()
-                {
-                    SizeFlagsVertical = SizeFlags.Fill,
-                };
+                var playerInfoText = new RichTextLabel();

                if (playerInfo.Observer)
                {
@@ -100,23 +95,11 @@ namespace Content.Client.UserInterface
            scrollContainer.AddChild(innerScrollContainer);
            //Attach the entire ScrollContainer that holds all the playerinfo.
            PlayerManifestoTab.AddChild(scrollContainer);
-            // TODO: 1240 Overlap, remove once it's fixed. Temp Hack to make the lines not overlap
-            PlayerManifestoTab.OnVisibilityChanged += PlayerManifestoTab_OnVisibilityChanged;

            //Finally, display the window.
            OpenCentered();
            MoveToFront();
        }
-
-        private void PlayerManifestoTab_OnVisibilityChanged(Control obj)
-        {
-            if (obj.Visible)
-            {
-                // For some reason the lines get not properly drawn with the right height
-                // so we just force a update
-                ForceRunLayoutUpdate();
-            }
-        }
    }

 }
--- a/Content.Client/UserInterface/ServerInfo.cs
+++ b/Content.Client/UserInterface/ServerInfo.cs
@@ -14,7 +14,7 @@ namespace Content.Client.UserInterface
        {
            _richTextLabel = new RichTextLabel
            {
-                SizeFlagsVertical = SizeFlags.FillExpand
+                VerticalExpand = true
            };
            AddChild(_richTextLabel);

--- a/Content.Client/UserInterface/StripeBack.cs
+++ b/Content.Client/UserInterface/StripeBack.cs
@@ -21,8 +21,8 @@ namespace Content.Client.UserInterface
            get => _hasTopEdge;
            set
            {
-                MinimumSizeChanged();
                _hasTopEdge = value;
+                InvalidateMeasure();
            }
        }

@@ -32,7 +32,7 @@ namespace Content.Client.UserInterface
            set
            {
                _hasBottomEdge = value;
-                MinimumSizeChanged();
+                InvalidateMeasure();
            }
        }

@@ -42,37 +42,36 @@ namespace Content.Client.UserInterface
            set
            {
                _hasMargins = value;
-                MinimumSizeChanged();
+                InvalidateMeasure();
            }
        }

-        protected override Vector2 CalculateMinimumSize()
+        protected override Vector2 MeasureOverride(Vector2 availableSize)
        {
+            var padSize = HasMargins ? PadSize : 0;
+            var padSizeTotal = 0f;
+
+            if (HasBottomEdge)
+                padSizeTotal += padSize + EdgeSize;
+            if (HasTopEdge)
+                padSizeTotal += padSize + EdgeSize;
+
            var size = Vector2.Zero;

+            availableSize.Y -= padSizeTotal;
+
            foreach (var child in Children)
            {
-                size = Vector2.ComponentMax(size, child.CombinedMinimumSize);
+                child.Measure(availableSize);
+                size = Vector2.ComponentMax(size, child.DesiredSize);
            }

-            var padSize = HasMargins ? PadSize : 0;
-
-            if (HasBottomEdge)
-            {
-                size += (0, padSize + EdgeSize);
-            }
-
-            if (HasTopEdge)
-            {
-                size += (0, padSize + EdgeSize);
-            }
-
-            return size;
+            return size + (0, padSizeTotal);
        }

-        protected override void LayoutUpdateOverride()
+        protected override Vector2 ArrangeOverride(Vector2 finalSize)
        {
-            var box = SizeBox;
+            var box = new UIBox2(Vector2.Zero, finalSize);

            var padSize = HasMargins ? PadSize : 0;

@@ -88,10 +87,13 @@ namespace Content.Client.UserInterface

            foreach (var child in Children)
            {
-                FitChildInBox(child, box);
+                child.Arrange(box);
            }
+
+            return finalSize;
        }

+
        protected override void Draw(DrawingHandleScreen handle)
        {
            UIBox2 centerBox = PixelSizeBox;
@@ -107,7 +109,8 @@ namespace Content.Client.UserInterface
            if (HasBottomEdge)
            {
                centerBox += (0, 0, 0, -((padSize + EdgeSize) * UIScale));
-                handle.DrawRect(new UIBox2(0, centerBox.Bottom, PixelWidth, PixelHeight - padSize * UIScale), EdgeColor);
+                handle.DrawRect(new UIBox2(0, centerBox.Bottom, PixelWidth, PixelHeight - padSize * UIScale),
+                    EdgeColor);
            }

            GetActualStyleBox()?.Draw(handle, centerBox);
--- a/Content.Client/UserInterface/StrippingMenu.cs
+++ b/Content.Client/UserInterface/StrippingMenu.cs
@@ -9,17 +9,16 @@ namespace Content.Client.UserInterface
 {
    public class StrippingMenu : SS14Window
    {
-        protected override Vector2? CustomSize => new Vector2(400, 600);
-
        private readonly VBoxContainer _vboxContainer;

        public StrippingMenu(string title)
        {
+            MinSize = SetSize = (400, 600);
            Title = title;

            _vboxContainer = new VBoxContainer()
            {
-                SizeFlagsVertical = SizeFlags.FillExpand,
+                VerticalExpand = true,
                SeparationOverride = 5,
            };

@@ -43,7 +42,7 @@ namespace Content.Client.UserInterface

            _vboxContainer.AddChild(new HBoxContainer()
            {
-                SizeFlagsHorizontal = SizeFlags.FillExpand,
+                HorizontalExpand = true,
                SeparationOverride = 5,
                Children =
                {
@@ -53,7 +52,7 @@ namespace Content.Client.UserInterface
                    },
                    new Control()
                    {
-                        SizeFlagsHorizontal = SizeFlags.FillExpand
+                        HorizontalExpand = true
                    },
                    button,
                }
--- a/Content.Client/UserInterface/Suspicion/SuspicionGui.xaml.cs
+++ b/Content.Client/UserInterface/Suspicion/SuspicionGui.xaml.cs
@@ -35,7 +35,7 @@ namespace Content.Client.UserInterface.Suspicion
            IoCManager.InjectDependencies(this);

            RoleButton.OnPressed += RoleButtonPressed;
-            RoleButton.CustomMinimumSize = (200, 60);
+            RoleButton.MinSize = (200, 60);
        }

        private void RoleButtonPressed(ButtonEventArgs obj)
--- a/Content.Client/UserInterface/TargetingDoll.cs
+++ b/Content.Client/UserInterface/TargetingDoll.cs
@@ -44,21 +44,21 @@ namespace Content.Client.UserInterface
            {
                TextureNormal = resourceCache.GetTexture(TextureHigh),
                StyleClasses = {StyleClassTargetDollZone},
-                SizeFlagsHorizontal = SizeFlags.ShrinkCenter
+                HorizontalAlignment = HAlignment.Center
            };

            _buttonMiddle = new TextureButton
            {
                TextureNormal = resourceCache.GetTexture(TextureMiddle),
                StyleClasses = {StyleClassTargetDollZone},
-                SizeFlagsHorizontal = SizeFlags.ShrinkCenter
+                HorizontalAlignment = HAlignment.Center
            };

            _buttonLow = new TextureButton
            {
                TextureNormal = resourceCache.GetTexture(TextureLow),
                StyleClasses = {StyleClassTargetDollZone},
-                SizeFlagsHorizontal = SizeFlags.ShrinkCenter
+                HorizontalAlignment = HAlignment.Center
            };

            _buttonHigh.OnPressed += _ => ActiveZone = TargetingZone.High;
--- a/Content.Client/UserInterface/TutorialWindow.cs
+++ b/Content.Client/UserInterface/TutorialWindow.cs
@@ -36,10 +36,9 @@ namespace Content.Client.UserInterface
 [color=#a4885c]AlignWall[/color] snaps to vertical halftiles.
 [color=#a4885c]AlignWallProper[/color] snaps the entity to the middle of the tile edges";

-        protected override Vector2? CustomSize => (520, 580);
-
        public TutorialWindow()
        {
+            MinSize = SetSize = (520, 580);
            Title = "The Tutorial!";

            //Get section header font