diff --git a/src/Clay.Test/ConfigTests.cs b/src/Clay.Test/ConfigTests.cs
index 30eb3e2..1663fb3 100644
--- a/src/Clay.Test/ConfigTests.cs
+++ b/src/Clay.Test/ConfigTests.cs
@@ -206,21 +206,21 @@ public void Container_SetsLayout()
     {
         var layout = LayoutConfig.FillRow(gap: 8);
         var decl = ElementDeclaration.Container(layout);
-        Assert.Equal(8, decl.Layout.ChildGap);
+        Assert.Equal(8, decl.Layout!.Value.ChildGap);
     }
 
     [Fact]
     public void Box_SetsLayoutAndColor()
     {
         var decl = ElementDeclaration.Box(LayoutConfig.FillRow(), Color.Red);
-        Assert.Equal(Color.Red.R, decl.BackgroundColor.R);
+        Assert.Equal(Color.Red.R, decl.BackgroundColor!.Value.R);
     }
 
     [Fact]
     public void RoundedBox_SetsCornerRadius()
     {
         var decl = ElementDeclaration.RoundedBox(LayoutConfig.FillRow(), Color.Red, 8f);
-        Assert.True(decl.CornerRadius.HasRadius);
+        Assert.True(decl.CornerRadius!.Value.HasRadius);
     }
 }
 
diff --git a/src/Clay.Test/OptionalElementDeclarationTests.cs b/src/Clay.Test/OptionalElementDeclarationTests.cs
new file mode 100644
index 0000000..2ea9709
--- /dev/null
+++ b/src/Clay.Test/OptionalElementDeclarationTests.cs
@@ -0,0 +1,401 @@
+using Clay;
+
+namespace Clay.Test;
+
+/// <summary>
+/// Tests for the nullable ElementDeclaration field contract.
+/// Declaring a config field (even default) opts the element into that config.
+/// Leaving the field null means the config is not emitted.
+/// Id remains required.
+/// </summary>
+public class OptionalElementDeclarationTests : IDisposable
+{
+    private readonly ClayFixture _fixture;
+
+    public OptionalElementDeclarationTests() => _fixture = new ClayFixture();
+
+    public void Dispose() => _fixture.Dispose();
+
+    private static int CountCommands(ReadOnlySpan<RenderCommand> commands, RenderCommandType type)
+    {
+        int n = 0;
+        foreach (var c in commands)
+            if (c.CommandType == type) n++;
+        return n;
+    }
+
+    // ============ Null-by-default contract ============
+
+    [Fact]
+    public void OnlyId_NoLayout_DoesNotCrash()
+    {
+        ClayApi.BeginLayout();
+        using (ClayApi.Element(new ElementDeclaration { Id = ClayApi.Id("only-id") })) { }
+        var commands = ClayApi.EndLayout();
+        Assert.Equal(0, CountCommands(commands, RenderCommandType.Rectangle));
+        Assert.Equal(0, CountCommands(commands, RenderCommandType.Border));
+        Assert.Equal(0, CountCommands(commands, RenderCommandType.Shadow));
+        Assert.Equal(0, CountCommands(commands, RenderCommandType.Custom));
+        Assert.Equal(0, CountCommands(commands, RenderCommandType.Image));
+    }
+
+    [Fact]
+    public void NullBackgroundColor_DoesNotEmitRectangle()
+    {
+        ClayApi.BeginLayout();
+        using (ClayApi.Element(new ElementDeclaration
+        {
+            Id = ClayApi.Id("no-bg"),
+            Layout = new LayoutConfig { Sizing = Sizing.FixedSize(50, 50) }
+        }))
+        { }
+        var commands = ClayApi.EndLayout();
+        Assert.Equal(0, CountCommands(commands, RenderCommandType.Rectangle));
+    }
+
+    [Fact]
+    public void NullScroll_DoesNotRegisterScrollContainer()
+    {
+        ClayApi.BeginLayout();
+        using (ClayApi.Element(new ElementDeclaration
+        {
+            Id = ClayApi.Id("no-scroll"),
+            Layout = new LayoutConfig { Sizing = Sizing.FixedSize(100, 100) }
+        }))
+        { }
+        ClayApi.EndLayout();
+        Assert.Equal(0, ClayApi.GetScrollContainerCount());
+    }
+
+    // ============ Declaration-is-enough contract ============
+
+    [Fact]
+    public void EmptyCustomConfig_EmitsCustomCommand()
+    {
+        // Regression for sentinel removal: assigning a default-constructed CustomConfig
+        // (CustomData == null) MUST still emit a Custom render command.
+        ClayApi.BeginLayout();
+        using (ClayApi.Element(new ElementDeclaration
+        {
+            Id = ClayApi.Id("custom-empty"),
+            Layout = new LayoutConfig { Sizing = Sizing.FixedSize(50, 50) },
+            Custom = new CustomConfig()
+        }))
+        { }
+        var commands = ClayApi.EndLayout();
+        Assert.Equal(1, CountCommands(commands, RenderCommandType.Custom));
+    }
+
+    [Fact]
+    public void EmptyShadowConfig_EmitsShadowCommand()
+    {
+        ClayApi.BeginLayout();
+        using (ClayApi.Element(new ElementDeclaration
+        {
+            Id = ClayApi.Id("shadow-empty"),
+            Layout = new LayoutConfig { Sizing = Sizing.FixedSize(50, 50) },
+            Shadow = new ShadowConfig()
+        }))
+        { }
+        var commands = ClayApi.EndLayout();
+        Assert.Equal(1, CountCommands(commands, RenderCommandType.Shadow));
+    }
+
+    [Fact]
+    public void EmptyBorderConfig_DoesNotCrash()
+    {
+        // BorderConfig with zero width is registered as a config (sentinel removed)
+        // but the visual border command is skipped downstream when Width.HasBorder is false.
+        // Confirms the declaration is accepted without throwing.
+        ClayApi.BeginLayout();
+        using (ClayApi.Element(new ElementDeclaration
+        {
+            Id = ClayApi.Id("border-empty"),
+            Layout = new LayoutConfig { Sizing = Sizing.FixedSize(50, 50) },
+            Border = new BorderConfig()
+        }))
+        { }
+        var commands = ClayApi.EndLayout();
+        Assert.Equal(0, CountCommands(commands, RenderCommandType.Border));
+    }
+
+    [Fact]
+    public void EmptyScrollConfig_RegistersScrollContainer()
+    {
+        ClayApi.BeginLayout();
+        using (ClayApi.Element(new ElementDeclaration
+        {
+            Id = ClayApi.Id("scroll-empty"),
+            Layout = new LayoutConfig { Sizing = Sizing.FixedSize(100, 100) },
+            Scroll = new ScrollConfig()
+        }))
+        { }
+        ClayApi.EndLayout();
+        Assert.True(ClayApi.GetScrollContainerCount() > 0);
+    }
+
+    [Fact]
+    public void AssignedBackgroundColor_EmitsRectangle()
+    {
+        ClayApi.BeginLayout();
+        using (ClayApi.Element(new ElementDeclaration
+        {
+            Id = ClayApi.Id("bg"),
+            Layout = new LayoutConfig { Sizing = Sizing.FixedSize(50, 50) },
+            BackgroundColor = Color.Red
+        }))
+        { }
+        var commands = ClayApi.EndLayout();
+        Assert.Equal(1, CountCommands(commands, RenderCommandType.Rectangle));
+    }
+
+    [Fact]
+    public void TransparentBackgroundColor_DoesNotCrash()
+    {
+        // Declaration accepts a transparent color; downstream rectangle emission
+        // still skips fully-invisible fills as an optimization.
+        ClayApi.BeginLayout();
+        using (ClayApi.Element(new ElementDeclaration
+        {
+            Id = ClayApi.Id("bg-transparent"),
+            Layout = new LayoutConfig { Sizing = Sizing.FixedSize(50, 50) },
+            BackgroundColor = new Color(0, 0, 0, 0)
+        }))
+        { }
+        var commands = ClayApi.EndLayout();
+        Assert.Equal(0, CountCommands(commands, RenderCommandType.Rectangle));
+    }
+
+    // ============ Regression: existing behavior preserved ============
+
+    [Fact]
+    public void Regression_BackgroundColor_StillEmitsRectangle()
+    {
+        ClayApi.BeginLayout();
+        using (ClayApi.Element(new ElementDeclaration
+        {
+            Id = ClayApi.Id("reg-bg"),
+            Layout = new LayoutConfig { Sizing = Sizing.FixedSize(100, 100) },
+            BackgroundColor = Color.Blue
+        }))
+        { }
+        var commands = ClayApi.EndLayout();
+        Assert.Equal(1, CountCommands(commands, RenderCommandType.Rectangle));
+    }
+
+    [Fact]
+    public void Regression_ImageConfig_WithData_EmitsImage()
+    {
+        ClayApi.BeginLayout();
+        using (ClayApi.Element(new ElementDeclaration
+        {
+            Id = ClayApi.Id("reg-image"),
+            Layout = new LayoutConfig { Sizing = Sizing.FixedSize(64, 64) },
+            Image = ImageConfig.Create(new object(), 64, 64)
+        }))
+        { }
+        var commands = ClayApi.EndLayout();
+        Assert.Equal(1, CountCommands(commands, RenderCommandType.Image));
+    }
+
+    [Fact]
+    public void Regression_ShadowDrop_EmitsShadow()
+    {
+        ClayApi.BeginLayout();
+        using (ClayApi.Element(new ElementDeclaration
+        {
+            Id = ClayApi.Id("reg-shadow"),
+            Layout = new LayoutConfig { Sizing = Sizing.FixedSize(50, 50) },
+            Shadow = ShadowConfig.Drop(2, 2, 4, Color.Black)
+        }))
+        { }
+        var commands = ClayApi.EndLayout();
+        Assert.Equal(1, CountCommands(commands, RenderCommandType.Shadow));
+    }
+
+    [Fact]
+    public void Regression_BorderUniform_EmitsBorder()
+    {
+        ClayApi.BeginLayout();
+        using (ClayApi.Element(new ElementDeclaration
+        {
+            Id = ClayApi.Id("reg-border"),
+            Layout = new LayoutConfig { Sizing = Sizing.FixedSize(50, 50) },
+            Border = BorderConfig.Uniform(2, Color.White)
+        }))
+        { }
+        var commands = ClayApi.EndLayout();
+        Assert.Equal(1, CountCommands(commands, RenderCommandType.Border));
+    }
+
+    [Fact]
+    public void Regression_ScrollVertical_RegistersScrollContainer()
+    {
+        ClayApi.BeginLayout();
+        using (ClayApi.Element(new ElementDeclaration
+        {
+            Id = ClayApi.Id("reg-scroll"),
+            Layout = new LayoutConfig { Sizing = Sizing.FixedSize(100, 100) },
+            Scroll = ScrollConfig.VerticalScroll
+        }))
+        {
+            using (ClayApi.Element(new ElementDeclaration
+            {
+                Layout = new LayoutConfig { Sizing = Sizing.FixedSize(100, 500) },
+                BackgroundColor = Color.Red
+            }))
+            { }
+        }
+        ClayApi.EndLayout();
+        Assert.True(ClayApi.GetScrollContainerCount() > 0);
+    }
+
+    [Fact]
+    public void Regression_ContainerFactory_StillBuilds()
+    {
+        ClayApi.BeginLayout();
+        using (ClayApi.Element(ElementDeclaration.Container(LayoutConfig.FillRow(gap: 4)))) { }
+        ClayApi.EndLayout();
+        Assert.True(ClayApi.GetElementCount() > 0);
+    }
+
+    [Fact]
+    public void Regression_BoxFactory_EmitsRectangle()
+    {
+        ClayApi.BeginLayout();
+        using (ClayApi.Element(ElementDeclaration.Box(
+            new LayoutConfig { Sizing = Sizing.FixedSize(50, 50) },
+            Color.Green))) { }
+        var commands = ClayApi.EndLayout();
+        Assert.Equal(1, CountCommands(commands, RenderCommandType.Rectangle));
+    }
+
+    [Fact]
+    public void Regression_RoundedBoxFactory_BuildsAndRenders()
+    {
+        ClayApi.BeginLayout();
+        using (ClayApi.Element(ElementDeclaration.RoundedBox(
+            new LayoutConfig { Sizing = Sizing.FixedSize(50, 50) },
+            Color.Green,
+            8f))) { }
+        var commands = ClayApi.EndLayout();
+        Assert.Equal(1, CountCommands(commands, RenderCommandType.Rectangle));
+    }
+
+    [Fact]
+    public void Regression_FloatingConfig_RegistersTreeRoot()
+    {
+        ClayApi.BeginLayout();
+        using (ClayApi.Element(new ElementDeclaration
+        {
+            Id = ClayApi.Id("float-parent"),
+            Layout = new LayoutConfig { Sizing = Sizing.FixedSize(200, 200) }
+        }))
+        {
+            using (ClayApi.Element(new ElementDeclaration
+            {
+                Id = ClayApi.Id("float-child"),
+                Layout = new LayoutConfig { Sizing = Sizing.FixedSize(50, 50) },
+                Floating = new FloatingConfig { AttachTo = FloatingAttachTo.Parent }
+            }))
+            { }
+        }
+        ClayApi.EndLayout();
+        // Root container + the floating element each get a tree root entry.
+        Assert.True(ClayApi.GetTreeRootCount() >= 2);
+    }
+
+    [Fact]
+    public void NullFloating_DoesNotAddTreeRoot()
+    {
+        ClayApi.BeginLayout();
+        int before = ClayApi.GetTreeRootCount();
+        using (ClayApi.Element(new ElementDeclaration
+        {
+            Id = ClayApi.Id("no-float"),
+            Layout = new LayoutConfig { Sizing = Sizing.FixedSize(50, 50) }
+        }))
+        { }
+        ClayApi.EndLayout();
+        // Only the root container's tree root should exist (added during BeginLayout).
+        Assert.Equal(1, ClayApi.GetTreeRootCount() - before + 1);
+    }
+
+    [Fact]
+    public void Regression_CornerRadius_AppliesToRectangle()
+    {
+        ClayApi.BeginLayout();
+        using (ClayApi.Element(new ElementDeclaration
+        {
+            Id = ClayApi.Id("rad"),
+            Layout = new LayoutConfig { Sizing = Sizing.FixedSize(50, 50) },
+            BackgroundColor = Color.Red,
+            CornerRadius = CornerRadius.All(6f)
+        }))
+        { }
+        var commands = ClayApi.EndLayout();
+        Assert.Equal(1, CountCommands(commands, RenderCommandType.Rectangle));
+    }
+
+    [Fact]
+    public void UserData_AssignedOrNull_DoesNotCrash()
+    {
+        // UserData is now nint? — both null and an assigned value must be accepted by the layout pipeline.
+        ClayApi.BeginLayout();
+        using (ClayApi.Element(new ElementDeclaration
+        {
+            Id = ClayApi.Id("ud-set"),
+            Layout = new LayoutConfig { Sizing = Sizing.FixedSize(50, 50) },
+            BackgroundColor = Color.Red,
+            UserData = (nint)0xABCD
+        }))
+        { }
+        using (ClayApi.Element(new ElementDeclaration
+        {
+            Id = ClayApi.Id("ud-null"),
+            Layout = new LayoutConfig { Sizing = Sizing.FixedSize(50, 50) },
+            BackgroundColor = Color.Red
+        }))
+        { }
+        var commands = ClayApi.EndLayout();
+        Assert.Equal(2, CountCommands(commands, RenderCommandType.Rectangle));
+    }
+
+    // ============ ClipContent / Scroll clip stack ============
+
+    [Fact]
+    public void NullLayout_DoesNotPushClipStack()
+    {
+        // Was previously checking layout.ClipContent — must tolerate null Layout.
+        ClayApi.BeginLayout();
+        using (ClayApi.Element(new ElementDeclaration { Id = ClayApi.Id("no-layout-clip") })) { }
+        var commands = ClayApi.EndLayout();
+        Assert.Equal(0, CountCommands(commands, RenderCommandType.ScissorStart));
+    }
+
+    [Fact]
+    public void Regression_ClipContent_EmitsScissor()
+    {
+        ClayApi.BeginLayout();
+        using (ClayApi.Element(new ElementDeclaration
+        {
+            Id = ClayApi.Id("clip"),
+            Layout = new LayoutConfig
+            {
+                Sizing = Sizing.FixedSize(100, 100),
+                ClipContent = true
+            }
+        }))
+        {
+            using (ClayApi.Element(new ElementDeclaration
+            {
+                Layout = new LayoutConfig { Sizing = Sizing.FixedSize(50, 50) },
+                BackgroundColor = Color.Red
+            }))
+            { }
+        }
+        var commands = ClayApi.EndLayout();
+        Assert.True(CountCommands(commands, RenderCommandType.ScissorStart) >= 1);
+        Assert.True(CountCommands(commands, RenderCommandType.ScissorEnd) >= 1);
+    }
+}
diff --git a/src/Clay/ClayUI.cs b/src/Clay/ClayUI.cs
index 0cbf3e7..61afcc3 100644
--- a/src/Clay/ClayUI.cs
+++ b/src/Clay/ClayUI.cs
@@ -1039,7 +1039,7 @@ public static void Image(object imageData, float width, float height, ImageStyle
             },
             Image = ImageConfig.Create(imageData, width, height),
             CornerRadius = s.CornerRadius,
-            Border = s.Border
+            Border = s.Border.HasBorder ? s.Border : null
         })) { }
     }
 
@@ -1711,8 +1711,8 @@ public static void BeginHorizontal(ushort gap = 8, ChildAlignment alignment = de
                 },
                 BackgroundColor = hasStyle ? s.BackgroundColor : default,
                 CornerRadius = hasStyle ? s.CornerRadius : default,
-                Border = hasStyle ? s.Border : default,
-                Shadow = hasStyle ? s.Shadow : default
+                Border = hasStyle && s.Border.HasBorder ? s.Border : null,
+                Shadow = hasStyle && s.Shadow.HasShadow ? s.Shadow : null
             });
             _context.LayoutDepth++;
 
@@ -1756,8 +1756,8 @@ public static void BeginHorizontal(ushort gap = 8, ChildAlignment alignment = de
                 },
                 BackgroundColor = hasStyle ? s.BackgroundColor : default,
                 CornerRadius = hasStyle ? s.CornerRadius : default,
-                Border = hasStyle ? s.Border : default,
-                Shadow = hasStyle ? s.Shadow : default
+                Border = hasStyle && s.Border.HasBorder ? s.Border : null,
+                Shadow = hasStyle && s.Shadow.HasShadow ? s.Shadow : null
             });
             _context.LayoutDepth++;
         }
@@ -1827,8 +1827,8 @@ public static void BeginVertical(ushort gap = 8, ChildAlignment alignment = defa
                 },
                 BackgroundColor = hasStyle ? s.BackgroundColor : default,
                 CornerRadius = hasStyle ? s.CornerRadius : default,
-                Border = hasStyle ? s.Border : default,
-                Shadow = hasStyle ? s.Shadow : default
+                Border = hasStyle && s.Border.HasBorder ? s.Border : null,
+                Shadow = hasStyle && s.Shadow.HasShadow ? s.Shadow : null
             });
             _context.LayoutDepth++;
 
@@ -1872,8 +1872,8 @@ public static void BeginVertical(ushort gap = 8, ChildAlignment alignment = defa
                 },
                 BackgroundColor = hasStyle ? s.BackgroundColor : default,
                 CornerRadius = hasStyle ? s.CornerRadius : default,
-                Border = hasStyle ? s.Border : default,
-                Shadow = hasStyle ? s.Shadow : default
+                Border = hasStyle && s.Border.HasBorder ? s.Border : null,
+                Shadow = hasStyle && s.Shadow.HasShadow ? s.Shadow : null
             });
             _context.LayoutDepth++;
         }
@@ -1948,7 +1948,7 @@ public static void BeginPanel(string title, PanelStyle? style = null, bool scrol
                 CornerRadius = sk.Background.HasImage ? CornerRadius.Zero : s.CornerRadius,
                 Border = sk.Background.HasImage ? default : s.Border,
                 Image = sk.Background.HasImage ? SkinToImageConfig(sk.Background) : default,
-                Shadow = s.Shadow
+                Shadow = s.Shadow.HasShadow ? s.Shadow : null
             });
             _context.PanelDepth++;
 
@@ -2042,7 +2042,7 @@ public static void BeginPanel(string title, PanelStyle? style = null, bool scrol
                 CornerRadius = sk.Background.HasImage ? CornerRadius.Zero : s.CornerRadius,
                 Border = sk.Background.HasImage ? default : s.Border,
                 Image = sk.Background.HasImage ? SkinToImageConfig(sk.Background) : default,
-                Shadow = s.Shadow
+                Shadow = s.Shadow.HasShadow ? s.Shadow : null
             });
             _context.PanelDepth++;
 
@@ -2447,7 +2447,7 @@ public static bool BeginWindow(string title, ref bool open, WindowStyle? style =
             CornerRadius = sk.Body.HasImage ? CornerRadius.Zero : s.CornerRadius,
             Border = sk.Body.HasImage ? default : s.Border,
             Image = sk.Body.HasImage ? SkinToImageConfig(sk.Body) : default,
-            Shadow = s.Shadow
+            Shadow = s.Shadow.HasShadow ? s.Shadow : null
         });
 
         // Title bar
@@ -3638,7 +3638,7 @@ public static void Tooltip(string text, TooltipStyle? style = null)
             },
             BackgroundColor = s.BackgroundColor,
             CornerRadius = s.CornerRadius,
-            Border = s.Border,
+            Border = s.Border.HasBorder ? s.Border : null,
             Floating = new FloatingConfig
             {
                 AttachTo = FloatingAttachTo.Root,
@@ -3729,7 +3729,7 @@ public static bool BeginTooltip(TooltipStyle? style = null)
             },
             BackgroundColor = s.BackgroundColor,
             CornerRadius = s.CornerRadius,
-            Border = s.Border,
+            Border = s.Border.HasBorder ? s.Border : null,
             Floating = new FloatingConfig
             {
                 AttachTo = FloatingAttachTo.Root,
@@ -3909,7 +3909,7 @@ public static bool BeginPopup(string id, PopupStyle? style = null)
             },
             BackgroundColor = s.BackgroundColor,
             CornerRadius = s.CornerRadius,
-            Border = s.Border,
+            Border = s.Border.HasBorder ? s.Border : null,
             Floating = new FloatingConfig
             {
                 AttachTo = FloatingAttachTo.Root,
@@ -4473,7 +4473,7 @@ public static bool BeginPopupModal(string id, ModalStyle? style = null)
             },
             BackgroundColor = s.BackgroundColor,
             CornerRadius = s.CornerRadius,
-            Border = s.Border,
+            Border = s.Border.HasBorder ? s.Border : null,
             Floating = new FloatingConfig
             {
                 AttachTo = FloatingAttachTo.Root,
@@ -5034,7 +5034,7 @@ public static void BeginScrollArea(string id, float? maxHeight = null, bool hori
                 },
                 BackgroundColor = s.BackgroundColor,
                 CornerRadius = s.CornerRadius,
-                Shadow = s.Shadow
+                Shadow = s.Shadow.HasShadow ? s.Shadow : null
             });
             _context.LayoutDepth++;
 
@@ -5083,7 +5083,7 @@ public static void BeginScrollArea(string id, float? maxHeight = null, bool hori
                 },
                 BackgroundColor = s.BackgroundColor,
                 CornerRadius = s.CornerRadius,
-                Shadow = s.Shadow
+                Shadow = s.Shadow.HasShadow ? s.Shadow : null
             });
             _context.LayoutDepth++;
 
@@ -5210,7 +5210,7 @@ public static void BeginListBox(string label, float maxHeight = 150, ListBoxStyl
             },
             BackgroundColor = s.BackgroundColor,
             CornerRadius = s.CornerRadius,
-            Border = s.Border
+            Border = s.Border.HasBorder ? s.Border : null
         });
         _context.LayoutDepth++;
         _context.LayoutScrollInfo.Push(new ClayUIContext.ScrollWrapperInfo(scrollId, IsVertical: true, HasWrapper: true));
@@ -5365,7 +5365,7 @@ public static bool Combo(string label, ref int selectedIndex, string[] options,
                 },
                 BackgroundColor = isHovered ? s.HoverColor : s.BackgroundColor,
                 CornerRadius = s.CornerRadius,
-                Border = s.Border
+                Border = s.Border.HasBorder ? s.Border : null
             }))
             {
                 // Selected text
diff --git a/src/Clay/Core/ClayContext.cs b/src/Clay/Core/ClayContext.cs
index 27d1a7e..ffe1d63 100644
--- a/src/Clay/Core/ClayContext.cs
+++ b/src/Clay/Core/ClayContext.cs
@@ -251,13 +251,14 @@ public void ConfigureOpenElement(ElementDeclaration declaration)
 
         ref var openLayoutElement = ref GetOpenLayoutElement();
 
-        // Store layout config
-        int layoutConfigIndex = LayoutConfigs.Add(declaration.Layout);
+        // Store layout config (default when not provided)
+        var layout = declaration.Layout ?? default;
+        int layoutConfigIndex = LayoutConfigs.Add(layout);
         openLayoutElement.LayoutConfigIndex = layoutConfigIndex;
 
         // Validate percent sizing
-        if ((declaration.Layout.Sizing.Width.Type == SizingType.Percent && declaration.Layout.Sizing.Width.Percent > 1) ||
-            (declaration.Layout.Sizing.Height.Type == SizingType.Percent && declaration.Layout.Sizing.Height.Percent > 1))
+        if ((layout.Sizing.Width.Type == SizingType.Percent && layout.Sizing.Width.Percent > 1) ||
+            (layout.Sizing.Height.Type == SizingType.Percent && layout.Sizing.Height.Percent > 1))
         {
             OnError?.Invoke(new ErrorData
             {
@@ -270,30 +271,30 @@ public void ConfigureOpenElement(ElementDeclaration declaration)
         openLayoutElement.ElementConfigsStart = ElementConfigs.Length;
 
         // Process shared config (background color, corner radius, user data)
-        if (declaration.BackgroundColor.A > 0 || declaration.CornerRadius.HasRadius || declaration.UserData != 0)
+        if (declaration.BackgroundColor is not null || declaration.CornerRadius is not null || declaration.UserData is not null)
         {
             int sharedIndex = SharedElementConfigs.Add(new SharedElementConfig
             {
-                BackgroundColor = declaration.BackgroundColor,
-                CornerRadius = declaration.CornerRadius,
-                UserData = declaration.UserData
+                BackgroundColor = declaration.BackgroundColor ?? default,
+                CornerRadius = declaration.CornerRadius ?? default,
+                UserData = declaration.UserData ?? 0
             });
             ElementConfigs.Add(new ElementConfig { Type = ElementConfigType.Shared, ConfigIndex = sharedIndex });
             openLayoutElement.ElementConfigsLength++;
         }
 
         // Process image config
-        if (declaration.Image.HasImage)
+        if (declaration.Image is not null)
         {
-            int imageIndex = ImageElementConfigs.Add(declaration.Image);
+            int imageIndex = ImageElementConfigs.Add(declaration.Image.Value);
             ElementConfigs.Add(new ElementConfig { Type = ElementConfigType.Image, ConfigIndex = imageIndex });
             openLayoutElement.ElementConfigsLength++;
         }
 
         // Process floating config
-        if (declaration.Floating.IsFloating)
+        if (declaration.Floating is not null)
         {
-            var floatingConfig = declaration.Floating;
+            var floatingConfig = declaration.Floating.Value;
 
             if (OpenLayoutElementStack.Length >= 2)
             {
@@ -335,9 +336,9 @@ public void ConfigureOpenElement(ElementDeclaration declaration)
         }
 
         // Process custom config
-        if (declaration.Custom.HasCustomData)
+        if (declaration.Custom is not null)
         {
-            int customIndex = CustomElementConfigs.Add(declaration.Custom);
+            int customIndex = CustomElementConfigs.Add(declaration.Custom.Value);
             ElementConfigs.Add(new ElementConfig { Type = ElementConfigType.Custom, ConfigIndex = customIndex });
             openLayoutElement.ElementConfigsLength++;
         }
@@ -353,15 +354,15 @@ public void ConfigureOpenElement(ElementDeclaration declaration)
         }
 
         // Push to clip stack if this element clips children (one entry per element)
-        if (declaration.Layout.ClipContent || declaration.Scroll.IsScrollable)
+        if (layout.ClipContent || declaration.Scroll is not null)
         {
             OpenClipElementStack.Add((int)openLayoutElement.Id);
         }
 
         // Process scroll config
-        if (declaration.Scroll.IsScrollable)
+        if (declaration.Scroll is not null)
         {
-            int scrollIndex = ScrollElementConfigs.Add(declaration.Scroll);
+            int scrollIndex = ScrollElementConfigs.Add(declaration.Scroll.Value);
             ElementConfigs.Add(new ElementConfig { Type = ElementConfigType.Scroll, ConfigIndex = scrollIndex });
             openLayoutElement.ElementConfigsLength++;
 
@@ -392,17 +393,17 @@ public void ConfigureOpenElement(ElementDeclaration declaration)
         }
 
         // Process border config
-        if (declaration.Border.HasBorder)
+        if (declaration.Border is not null)
         {
-            int borderIndex = BorderElementConfigs.Add(declaration.Border);
+            int borderIndex = BorderElementConfigs.Add(declaration.Border.Value);
             ElementConfigs.Add(new ElementConfig { Type = ElementConfigType.Border, ConfigIndex = borderIndex });
             openLayoutElement.ElementConfigsLength++;
         }
 
         // Process shadow config
-        if (declaration.Shadow.HasShadow)
+        if (declaration.Shadow is not null)
         {
-            int shadowIndex = ShadowElementConfigs.Add(declaration.Shadow);
+            int shadowIndex = ShadowElementConfigs.Add(declaration.Shadow.Value);
             ElementConfigs.Add(new ElementConfig { Type = ElementConfigType.Shadow, ConfigIndex = shadowIndex });
             openLayoutElement.ElementConfigsLength++;
         }
diff --git a/src/Clay/Elements/ElementDeclaration.cs b/src/Clay/Elements/ElementDeclaration.cs
index 33997fc..7aceb2b 100644
--- a/src/Clay/Elements/ElementDeclaration.cs
+++ b/src/Clay/Elements/ElementDeclaration.cs
@@ -9,59 +9,59 @@ namespace Clay;
 public struct ElementDeclaration
 {
     /// <summary>
-    /// Unique identifier for this element.
+    /// Unique identifier for this element. Required.
     /// </summary>
     public ElementId Id;
 
     /// <summary>
     /// Layout configuration (sizing, padding, direction, etc.).
     /// </summary>
-    public LayoutConfig Layout;
+    public LayoutConfig? Layout;
 
     /// <summary>
     /// Background color of the element.
     /// </summary>
-    public Color BackgroundColor;
+    public Color? BackgroundColor;
 
     /// <summary>
     /// Corner radius for rounded corners.
     /// </summary>
-    public CornerRadius CornerRadius;
+    public CornerRadius? CornerRadius;
 
     /// <summary>
     /// Image configuration (if this is an image element).
     /// </summary>
-    public ImageConfig Image;
+    public ImageConfig? Image;
 
     /// <summary>
     /// Floating configuration (for overlay/popup elements).
     /// </summary>
-    public FloatingConfig Floating;
+    public FloatingConfig? Floating;
 
     /// <summary>
     /// Custom element configuration.
     /// </summary>
-    public CustomConfig Custom;
+    public CustomConfig? Custom;
 
     /// <summary>
     /// Scroll container configuration.
     /// </summary>
-    public ScrollConfig Scroll;
+    public ScrollConfig? Scroll;
 
     /// <summary>
     /// Border configuration.
     /// </summary>
-    public BorderConfig Border;
+    public BorderConfig? Border;
 
     /// <summary>
     /// Shadow configuration.
     /// </summary>
-    public ShadowConfig Shadow;
+    public ShadowConfig? Shadow;
 
     /// <summary>
     /// User-defined data (passed through to render commands).
     /// </summary>
-    public nint UserData;
+    public nint? UserData;
 
     /// <summary>
     /// Creates a basic container element.
@@ -83,7 +83,7 @@ public static ElementDeclaration RoundedBox(LayoutConfig layout, Color backgroun
         {
             Layout = layout,
             BackgroundColor = backgroundColor,
-            CornerRadius = CornerRadius.All(cornerRadius)
+            CornerRadius = global::Clay.CornerRadius.All(cornerRadius)
         };
 }