diff --git a/Assets/XCUI/NewEditor/Demo/View.xcui b/Assets/XCUI/NewEditor/Demo/View.xcui
index 7b515660..007a3540 100644
--- a/Assets/XCUI/NewEditor/Demo/View.xcui
+++ b/Assets/XCUI/NewEditor/Demo/View.xcui
@@ -50,6 +50,10 @@
           min-width="240"
           placeholder="Type a command or note for XCUI..."
           value="" />
+        <Text
+          id="promptMeta"
+          text="Single-line input, Enter submits"
+          style="Meta" />
       </Column>
     </Card>
     <Card id="notesCard" style="MetricCard">
@@ -61,8 +65,13 @@
           width="stretch"
           min-width="240"
           rows="4"
+          show-line-numbers="true"
           placeholder="Write multiline notes, prompts, or todos for the current screen..."
           value="" />
+        <Text
+          id="notesMeta"
+          text="Multiline input, click caret, Tab indent"
+          style="Meta" />
       </Column>
     </Card>
     <Button id="toggleAccent" action="demo.toggleAccent" style="AccentButton">
diff --git a/docs/plan/XCUI_Phase_Status_2026-04-05.md b/docs/plan/XCUI_Phase_Status_2026-04-05.md
index 21946169..44eddd61 100644
--- a/docs/plan/XCUI_Phase_Status_2026-04-05.md
+++ b/docs/plan/XCUI_Phase_Status_2026-04-05.md
@@ -13,6 +13,9 @@ Old `editor` replacement is explicitly out of scope for this phase.
   - schema document definition data is now retained on `UIDocumentModel` and round-trips through the UI artifact path
   - engine runtime coverage was tightened again around `UISystem` and concrete document-host rendering
   - `LayoutLab` continues as the editor widget proving ground for tree/list/property-section style controls
+- The current editor-host checkpoint additionally hardens the XCUI demo text-editing path and the temporary ImGui host bridge:
+  - multiline demo text areas now support pointer caret placement, line-number gutters, and tab indent/unindent behavior
+  - the ImGui bridge now accepts existing shader-resource views and the window renderer exposes an after-UI callback seam
 - Old `editor` replacement remains deferred; all active execution still stays inside XCUI shared code and `new_editor`.
 
 ## Three-Layer Status
@@ -26,6 +29,7 @@ Old `editor` replacement is explicitly out of scope for this phase.
 - Build-system hardening for MSVC/PDB output paths has started in root CMake, `engine/CMakeLists.txt`, `new_editor/CMakeLists.txt`, and `tests/NewEditor/CMakeLists.txt`.
 - Shared engine-side XCUI runtime scaffolding is now present under `engine/include/XCEngine/UI/Runtime` and `engine/src/UI/Runtime`.
 - Shared engine-side `UIDocumentScreenHost` now compiles `.xcui` / `.xctheme` screen documents into a runtime-facing document host path instead of leaving all document ownership in `new_editor`.
+- The temporary ImGui bridge can now register an existing shader-resource view directly instead of forcing the caller to recreate a texture SRV from scratch.
 - Core regression coverage now includes `UIContext`, layout, style, runtime screen player/system, and real document-host tests through `core_ui_tests`.
 
 Current gap:
@@ -52,11 +56,12 @@ Current gap:
 - `new_editor` remains the isolated XCUI sandbox.
 - Native hosted preview is working as `RHI offscreen surface -> ImGui shell texture embed`.
 - `XCUI Demo` remains the long-lived effect and behavior testbed.
-- `XCUI Demo` now covers both single-line and multiline text authoring behavior.
+- `XCUI Demo` now covers both single-line and multiline text authoring behavior, including pointer caret placement, line-number gutters, delete/backspace symmetry, and tab indent/unindent in text areas.
 - `LayoutLab` now includes a `ScrollView` prototype and a more editor-like three-column authored layout.
 - `LayoutLab` now also covers editor-facing widget prototypes: `TreeView`, `TreeItem`, `ListView`, `ListItem`, `PropertySection`, and `FieldRow`.
 - Panel diagnostics were expanded to clearly separate preview/runtime/input state and native vs legacy paths.
 - `XCNewEditor` builds successfully to `build/new_editor/bin/Debug/XCNewEditor.exe`.
+- `new_editor` host plumbing now has a narrower swapchain seam via a window-renderer post-ImGui callback, which is the first practical hook for a future window-level compositor split.
 
 Current gap:
 
@@ -73,11 +78,17 @@ Current gap:
 - `core_ui_tests`: `14/14`
 - `core_ui_style_tests`: `5/5`
 - `ui_resource_tests`: `7/7`
+- `editor_tests` targeted XCUI/editor host API smoke cases: `3/3`
 
 ## Landed This Phase
 
 - Demo runtime `TextField` with UTF-8 text insertion, caret state, and backspace.
 - Demo runtime multiline `TextArea` path in the sandbox and test coverage for caret movement / multiline input.
+- Demo runtime text editing extended with:
+  - pointer-based caret placement for text inputs
+  - multiline text-area line-number gutters
+  - tab indent / shift-tab unindent
+  - delete handling symmetry with backspace
 - Demo authored resources updated to exercise the input field.
 - LayoutLab `ScrollView` prototype with clipping and hover rejection outside clipped content.
 - LayoutLab editor-widget prototypes for tree/list/property-style sections with dedicated runtime coverage.
@@ -98,6 +109,10 @@ Current gap:
   - external texture binding reuse
   - per-batch scissor application
 - `new_editor` panel/shell diagnostics improvements for hosted preview state.
+- ImGui host bridge improvements:
+  - existing shader-resource view registration overload
+  - swapchain render callback seam after ImGui submission
+  - editor-side API smoke coverage for bridge and window renderer accessors
 - XCUI asset document loading changed to prefer direct source compilation before `ResourceManager` fallback for the sandbox path, fixing the LayoutLab crash.
 - `UIDocumentCompiler.cpp` repaired enough to restore full local builds after the duplicated schema-helper regression.
 - MSVC debug build hardening was tightened again so large parallel `engine` rebuilds stop tripping over compile-PDB contention.
diff --git a/editor/src/Platform/D3D12WindowRenderer.h b/editor/src/Platform/D3D12WindowRenderer.h
index d6af3e3f..23007cc9 100644
--- a/editor/src/Platform/D3D12WindowRenderer.h
+++ b/editor/src/Platform/D3D12WindowRenderer.h
@@ -182,7 +182,8 @@ public:
     void Render(
         UI::ImGuiBackendBridge& imguiBackend,
         const float clearColor[4],
-        const RenderCallback& beforeUiRender = {}) {
+        const RenderCallback& beforeUiRender = {},
+        const RenderCallback& afterUiRender = {}) {
         auto* d3d12Queue = GetD3D12CommandQueue();
         auto* d3d12CommandList = GetD3D12CommandList();
         if (m_swapChain == nullptr ||
@@ -222,6 +223,11 @@ public:
         d3d12CommandList->SetDescriptorHeaps(1, descriptorHeaps);
         imguiBackend.RenderDrawData(d3d12CommandList->GetCommandList());
 
+        if (afterUiRender) {
+            d3d12CommandList->SetRenderTargets(1, &renderTargetView, nullptr);
+            afterUiRender(GetRenderContext(), renderSurface);
+        }
+
         d3d12CommandList->TransitionBarrier(
             renderTargetView,
             RHI::ResourceStates::RenderTarget,
diff --git a/editor/src/UI/ImGuiBackendBridge.h b/editor/src/UI/ImGuiBackendBridge.h
index 8e7720c5..bf188c15 100644
--- a/editor/src/UI/ImGuiBackendBridge.h
+++ b/editor/src/UI/ImGuiBackendBridge.h
@@ -7,8 +7,10 @@
 #include <d3d12.h>
 #include <dxgi1_6.h>
 #include <XCEngine/RHI/D3D12/D3D12Device.h>
+#include <XCEngine/RHI/D3D12/D3D12ResourceView.h>
 #include <XCEngine/RHI/D3D12/D3D12Texture.h>
 #include <XCEngine/RHI/RHIDevice.h>
+#include <XCEngine/RHI/RHIResourceView.h>
 #include <XCEngine/RHI/RHITexture.h>
 #include <imgui.h>
 #include <imgui_impl_dx12.h>
@@ -168,6 +170,63 @@ public:
         return true;
     }
 
+    bool CreateTextureDescriptor(
+        ::XCEngine::RHI::RHIDevice* device,
+        ::XCEngine::RHI::RHIResourceView* shaderResourceView,
+        D3D12_CPU_DESCRIPTOR_HANDLE* outCpuHandle,
+        D3D12_GPU_DESCRIPTOR_HANDLE* outGpuHandle,
+        ImTextureID* outTextureId) {
+        if (device == nullptr ||
+            shaderResourceView == nullptr ||
+            outCpuHandle == nullptr ||
+            outGpuHandle == nullptr ||
+            outTextureId == nullptr) {
+            return false;
+        }
+
+        *outCpuHandle = {};
+        *outGpuHandle = {};
+        *outTextureId = {};
+
+        auto* nativeDevice = dynamic_cast<::XCEngine::RHI::D3D12Device*>(device);
+        auto* nativeView = dynamic_cast<::XCEngine::RHI::D3D12ResourceView*>(shaderResourceView);
+        if (nativeDevice == nullptr ||
+            nativeView == nullptr ||
+            !nativeView->IsValid() ||
+            nativeView->GetViewType() != ::XCEngine::RHI::ResourceViewType::ShaderResource) {
+            return false;
+        }
+
+        if (m_srvHeap == nullptr ||
+            m_srvDescriptorSize == 0 ||
+            m_srvUsage.empty() ||
+            std::find(m_srvUsage.begin(), m_srvUsage.end(), false) == m_srvUsage.end()) {
+            return false;
+        }
+
+        const D3D12_CPU_DESCRIPTOR_HANDLE sourceCpuHandle = nativeView->GetCPUHandle();
+        if (sourceCpuHandle.ptr == 0) {
+            return false;
+        }
+
+        AllocateTextureDescriptor(outCpuHandle, outGpuHandle);
+        if (outCpuHandle->ptr == 0 || outGpuHandle->ptr == 0) {
+            *outCpuHandle = {};
+            *outGpuHandle = {};
+            return false;
+        }
+
+        // ImGui samples from its own shader-visible heap, so copy the existing SRV into an ImGui-owned slot.
+        nativeDevice->GetDevice()->CopyDescriptorsSimple(
+            1,
+            *outCpuHandle,
+            sourceCpuHandle,
+            D3D12_DESCRIPTOR_HEAP_TYPE_CBV_SRV_UAV);
+
+        *outTextureId = static_cast<ImTextureID>(outGpuHandle->ptr);
+        return true;
+    }
+
     void FreeTextureDescriptor(
         D3D12_CPU_DESCRIPTOR_HANDLE cpuHandle,
         D3D12_GPU_DESCRIPTOR_HANDLE gpuHandle) {
diff --git a/new_editor/resources/xcui_demo_view.xcui b/new_editor/resources/xcui_demo_view.xcui
index 440b246f..7ff13898 100644
--- a/new_editor/resources/xcui_demo_view.xcui
+++ b/new_editor/resources/xcui_demo_view.xcui
@@ -1,30 +1,59 @@
 <View name="NewEditor Demo" theme="xcui_demo_theme.xctheme" style="Root">
-  <Column id="rootColumn" gap="12" padding="18">
+  <Column id="rootColumn" gap="10" padding="16">
     <Card id="hero" style="HeroCard">
-      <Column gap="6">
+      <Column gap="4">
         <Text id="title" text="New XCUI Shell" style="HeroTitle" />
         <Text id="subtitle" text="Markup -> Layout -> Style -> DrawData" style="HeroSubtitle" />
       </Column>
     </Card>
     <Row id="metricRow" gap="10">
       <Card id="metric1" style="MetricCard" width="stretch">
-        <Text text="Tree status" style="MetricLabel" />
-        <Text text="Driven by runtime" style="MetricValue" />
+        <Column gap="6">
+          <Text text="Tree status" style="MetricLabel" />
+          <Text text="Driven by runtime" style="MetricValue" />
+          <ProgressBar
+            id="densityMeter"
+            text="Density stress"
+            state-key="toggleDensity"
+            value-off="0.44"
+            value-on="0.86"
+            fill="token:color.accent"
+            width="stretch" />
+        </Column>
       </Card>
       <Card id="metric2" style="MetricCard" width="stretch">
-        <Text text="Input" style="MetricLabel" />
-        <Text text="Hover + shortcuts" style="MetricValue" />
+        <Column gap="6">
+          <Text text="Input" style="MetricLabel" />
+          <Text text="Hover + shortcuts" style="MetricValue" />
+          <Row gap="6">
+            <Swatch id="swatchAccent" text="Accent" token="color.accent" width="stretch" height="24" />
+            <Swatch id="swatchAlt" text="Alt" token="color.accent.alt" width="stretch" height="24" />
+          </Row>
+        </Column>
       </Card>
     </Row>
+    <Row id="toggleRow" gap="8">
+      <Toggle id="toggleDensity" text="Density stress" width="stretch" />
+      <Toggle
+        id="toggleDiagnostics"
+        text="Debug path"
+        width="stretch"
+        fill="token:color.accent.alt" />
+    </Row>
     <Card id="commandCard" style="MetricCard">
       <Column gap="6">
         <Text text="Agent command" style="MetricLabel" />
         <TextField
           id="agentPrompt"
+          style="CommandField"
           width="stretch"
           min-width="240"
           placeholder="Type a command or note for XCUI..."
           value="" />
+        <Text
+          id="promptMeta"
+          text="Single-line input, Enter submits"
+          style="Meta" />
       </Column>
     </Card>
     <Card id="notesCard" style="MetricCard">
@@ -32,21 +61,28 @@
         <Text text="Session notes" style="MetricLabel" />
         <TextArea
           id="sessionNotes"
+          style="CommandArea"
           width="stretch"
           min-width="240"
           rows="4"
+          show-line-numbers="true"
           placeholder="Write multiline notes, prompts, or todos for the current screen..."
           value="" />
+        <Text
+          id="notesMeta"
+          text="Multiline input, click caret, Tab indent"
+          style="Meta" />
       </Column>
     </Card>
-    <Button id="toggleAccent" style="AccentButton">
+    <Button id="toggleAccent" action="demo.toggleAccent" style="AccentButton">
       <Text text="Toggle Accent" style="ButtonLabel" />
     </Button>
     <Card id="debug" style="DebugCard">
-      <Column gap="4">
+      <Column gap="3">
         <Text id="statusFocus" text="Focus: waiting" style="Meta" />
         <Text id="statusLayout" text="Layout: idle" style="Meta" />
         <Text id="statusCommands" text="Commands: ready" style="Meta" />
+        <Text id="statusWidgets" text="Widgets: ready" style="Meta" />
       </Column>
     </Card>
   </Column>
diff --git a/new_editor/src/XCUIBackend/XCUIDemoRuntime.cpp b/new_editor/src/XCUIBackend/XCUIDemoRuntime.cpp
index b010b13b..f3ba7b3c 100644
--- a/new_editor/src/XCUIBackend/XCUIDemoRuntime.cpp
+++ b/new_editor/src/XCUIBackend/XCUIDemoRuntime.cpp
@@ -64,6 +64,9 @@ constexpr char kViewRelativePath[] = "new_editor/resources/xcui_demo_view.xcui";
 constexpr char kThemeRelativePath[] = "new_editor/resources/xcui_demo_theme.xctheme";
 constexpr char kToggleAccentCommandId[] = "demo.toggleAccent";
 constexpr float kApproximateTextWidthFactor = 0.58f;
+constexpr float kTextInputTextInset = 2.0f;
+constexpr float kTextAreaLineNumberGap = 10.0f;
+constexpr std::size_t kTextAreaTabWidth = 4u;
 
 struct DemoNode {
     UIElementId elementId = 0;
@@ -480,6 +483,19 @@ std::vector<std::string> SplitLines(const std::string& text) {
     return lines;
 }
 
+std::size_t CountTextLines(const std::string& text) {
+    return SplitLines(text).size();
+}
+
+std::size_t CountDecimalDigits(std::size_t value) {
+    std::size_t digits = 1u;
+    while (value >= 10u) {
+        value /= 10u;
+        ++digits;
+    }
+    return digits;
+}
+
 std::size_t CountUtf8CodepointsInRange(
     const std::string& text,
     std::size_t beginOffset,
@@ -564,6 +580,50 @@ std::size_t MoveCaretVertically(
         (std::min)(column, nextLineLength));
 }
 
+bool ShouldShowTextAreaLineNumbers(const DemoNode& node) {
+    bool showLineNumbers = false;
+    return IsTextAreaNode(node) &&
+        TryParseBool(GetNodeAttribute(node, "show-line-numbers"), showLineNumbers) &&
+        showLineNumbers;
+}
+
+float ResolveTextAreaGutterWidth(
+    const DemoNode& node,
+    std::size_t visibleLineCount,
+    float fontSize) {
+    if (!ShouldShowTextAreaLineNumbers(node)) {
+        return 0.0f;
+    }
+
+    const std::size_t digits = CountDecimalDigits((std::max)(std::size_t(1u), visibleLineCount));
+    const float numberWidth = MeasureGlyphRunWidth(std::string(digits, '8'), fontSize * 0.9f);
+    return numberWidth + kTextAreaLineNumberGap;
+}
+
+std::size_t FindCaretOffsetForHorizontalPosition(
+    const std::string& text,
+    std::size_t lineStart,
+    std::size_t lineEnd,
+    float targetX,
+    float fontSize) {
+    lineStart = (std::min)(lineStart, text.size());
+    lineEnd = (std::min)(lineEnd, text.size());
+    targetX = (std::max)(0.0f, targetX);
+
+    std::size_t caret = lineStart;
+    while (caret < lineEnd) {
+        const std::size_t nextCaret = AdvanceUtf8Offset(text, caret);
+        const float currentWidth = MeasureGlyphRunWidth(text.substr(lineStart, caret - lineStart), fontSize);
+        const float nextWidth = MeasureGlyphRunWidth(text.substr(lineStart, nextCaret - lineStart), fontSize);
+        if (targetX < (currentWidth + nextWidth) * 0.5f) {
+            return caret;
+        }
+        caret = nextCaret;
+    }
+
+    return lineEnd;
+}
+
 Style::UIStyleValue ParseThemeTokenValue(
     const std::string& typeName,
     const std::string& rawValue,
@@ -756,6 +816,9 @@ void ConfigureDemoStyleSheet(Style::UIStyleSheet& styleSheet) {
     styleSheet.GetOrCreateNamedStyle("CommandField").SetProperty(
         Style::UIStylePropertyId::BorderColor,
         Style::UIStyleValue::Token("color.accent.alt"));
+    styleSheet.GetOrCreateNamedStyle("CommandArea").SetProperty(
+        Style::UIStylePropertyId::BorderColor,
+        Style::UIStyleValue::Token("color.outline"));
     styleSheet.GetOrCreateNamedStyle("Meta").SetProperty(
         Style::UIStylePropertyId::ForegroundColor,
         Style::UIStyleValue::Token("color.text.secondary"));
@@ -887,6 +950,22 @@ std::string BuildNodeDisplayText(
             " / debug " +
             std::string(diagnosticsEnabled ? "on" : "off");
     }
+    if (node.elementKey == "promptMeta") {
+        const auto promptIt = state.textFieldValues.find("agentPrompt");
+        const std::string& promptValue =
+            promptIt != state.textFieldValues.end() ? promptIt->second : node.staticText;
+        return "Single-line input, Enter submits, " +
+            std::to_string(static_cast<unsigned long long>(CountUtf8Codepoints(promptValue))) +
+            " chars";
+    }
+    if (node.elementKey == "notesMeta") {
+        const auto notesIt = state.textFieldValues.find("sessionNotes");
+        const std::string& notesValue =
+            notesIt != state.textFieldValues.end() ? notesIt->second : node.staticText;
+        return "Multiline input, click caret, Tab indent, " +
+            std::to_string(static_cast<unsigned long long>(CountTextLines(notesValue))) +
+            " lines";
+    }
     if (node.elementKey == "subtitle" && stats.accentEnabled) {
         return "Markup -> Layout -> Style -> DrawData (accent alt active)";
     }
@@ -1076,6 +1155,62 @@ DemoNode* TryGetNodeByElementId(RuntimeBuildContext& state, UIElementId elementI
     return it != state.nodeIndexById.end() ? &state.nodes[it->second] : nullptr;
 }
 
+std::size_t FindCaretOffsetFromPoint(
+    RuntimeBuildContext& state,
+    const DemoNode& node,
+    const UIPoint& point) {
+    EnsureTextInputStateInitialized(state, node);
+    const std::string value = ResolveTextInputValue(state, node);
+    const Layout::UILayoutThickness padding =
+        ResolvePadding(node, state.activeTheme, state.styleSheet);
+    const UIRect contentRect = InsetRect(node.rect, padding);
+    const float fontSize = GetFloatProperty(
+        node,
+        state.activeTheme,
+        state.styleSheet,
+        Style::UIStylePropertyId::FontSize,
+        14.0f);
+
+    if (!IsTextAreaNode(node)) {
+        const float targetX = point.x - (contentRect.x + kTextInputTextInset);
+        return FindCaretOffsetForHorizontalPosition(value, 0u, value.size(), targetX, fontSize);
+    }
+
+    const float lineHeight = MeasureTextHeight(fontSize);
+    const std::size_t lineCount = (std::max)(std::size_t(1u), CountTextLines(value));
+    const float gutterWidth = ResolveTextAreaGutterWidth(node, lineCount, fontSize);
+    const float localY = point.y - (contentRect.y + kTextInputTextInset);
+    const float clampedY = (std::max)(0.0f, localY);
+    const std::size_t lineIndex = (std::min)(
+        static_cast<std::size_t>(clampedY / (std::max)(1.0f, lineHeight)),
+        lineCount - 1u);
+
+    std::size_t lineStart = 0u;
+    for (std::size_t currentLine = 0u; currentLine < lineIndex && lineStart < value.size(); ++currentLine) {
+        lineStart = FindLineEndOffset(value, lineStart);
+        if (lineStart < value.size()) {
+            ++lineStart;
+        }
+    }
+
+    const std::size_t lineEnd = FindLineEndOffset(value, lineStart);
+    const float targetX = point.x - (contentRect.x + kTextInputTextInset + gutterWidth);
+    return FindCaretOffsetForHorizontalPosition(value, lineStart, lineEnd, targetX, fontSize);
+}
+
+void SetTextInputCaretFromPoint(
+    RuntimeBuildContext& state,
+    UIElementId elementId,
+    const UIPoint& point) {
+    DemoNode* node = TryGetNodeByElementId(state, elementId);
+    if (node == nullptr || !IsTextInputNode(*node)) {
+        return;
+    }
+
+    const std::string stateKey = ResolveTextInputStateKey(*node);
+    state.textFieldCarets[stateKey] = FindCaretOffsetFromPoint(state, *node, point);
+}
+
 bool HandleTextInputCharacterInput(
     RuntimeBuildContext& state,
     UIElementId elementId,
@@ -1110,7 +1245,8 @@ bool HandleTextInputCharacterInput(
 bool HandleTextInputKeyDown(
     RuntimeBuildContext& state,
     UIElementId elementId,
-    std::int32_t keyCode) {
+    std::int32_t keyCode,
+    const UI::UIInputModifiers& inputModifiers) {
     DemoNode* node = TryGetNodeByElementId(state, elementId);
     if (node == nullptr || !IsTextInputNode(*node)) {
         return false;
@@ -1122,8 +1258,7 @@ bool HandleTextInputKeyDown(
     std::size_t& caret = state.textFieldCarets[stateKey];
     caret = (std::min)(caret, value.size());
 
-    if (keyCode == static_cast<std::int32_t>(KeyCode::Backspace) ||
-        keyCode == static_cast<std::int32_t>(KeyCode::Delete)) {
+    if (keyCode == static_cast<std::int32_t>(KeyCode::Backspace)) {
         if (caret > 0u) {
             const std::size_t previousCaret = RetreatUtf8Offset(value, caret);
             value.erase(previousCaret, caret - previousCaret);
@@ -1133,6 +1268,15 @@ bool HandleTextInputKeyDown(
         return true;
     }
 
+    if (keyCode == static_cast<std::int32_t>(KeyCode::Delete)) {
+        if (caret < value.size()) {
+            const std::size_t nextCaret = AdvanceUtf8Offset(value, caret);
+            value.erase(caret, nextCaret - caret);
+            state.lastCommandId = "demo.text.edit." + stateKey;
+        }
+        return true;
+    }
+
     if (keyCode == static_cast<std::int32_t>(KeyCode::Left)) {
         caret = RetreatUtf8Offset(value, caret);
         return true;
@@ -1179,6 +1323,33 @@ bool HandleTextInputKeyDown(
         return true;
     }
 
+    if (keyCode == static_cast<std::int32_t>(KeyCode::Tab) &&
+        IsTextAreaNode(*node) &&
+        !inputModifiers.control &&
+        !inputModifiers.alt &&
+        !inputModifiers.super) {
+        if (inputModifiers.shift) {
+            const std::size_t lineStart = FindLineStartOffset(value, caret);
+            std::size_t removed = 0u;
+            while (removed < kTextAreaTabWidth &&
+                lineStart + removed < value.size() &&
+                value[lineStart + removed] == ' ') {
+                ++removed;
+            }
+
+            if (removed > 0u) {
+                value.erase(lineStart, removed);
+                caret = caret >= lineStart + removed ? caret - removed : lineStart;
+                state.lastCommandId = "demo.text.edit." + stateKey;
+            }
+        } else {
+            value.insert(caret, std::string(kTextAreaTabWidth, ' '));
+            caret += kTextAreaTabWidth;
+            state.lastCommandId = "demo.text.edit." + stateKey;
+        }
+        return true;
+    }
+
     return false;
 }
 
@@ -1385,11 +1556,13 @@ UISize MeasureNode(RuntimeBuildContext& state, std::size_t index) {
                 lineCount,
                 static_cast<std::size_t>((std::max)(1.0f, requestedRows)));
         }
+        const float gutterWidth = ResolveTextAreaGutterWidth(node, lineCount, fontSize);
 
         node.desiredSize = UISize(
             (std::max)(
                 minWidth,
                 widestLine +
+                    gutterWidth +
                     padding.Horizontal() +
                     18.0f),
             lineHeight * static_cast<float>(lineCount) +
@@ -1665,7 +1838,7 @@ void DrawTextFieldNode(RuntimeBuildContext& state, const DemoNode& node, UIDrawL
 
     const float textY = contentRect.y + (contentRect.height - fontSize) * 0.5f - 2.0f;
     drawList.AddText(
-        UIPoint(contentRect.x + 2.0f, textY),
+        UIPoint(contentRect.x + kTextInputTextInset, textY),
         displayText,
         ToUIColor(textColor),
         fontSize);
@@ -1680,7 +1853,7 @@ void DrawTextFieldNode(RuntimeBuildContext& state, const DemoNode& node, UIDrawL
     const std::size_t caret = ResolveTextInputCaret(state, node);
     const float caretX =
         contentRect.x +
-        2.0f +
+        kTextInputTextInset +
         MeasureGlyphRunWidth(value.substr(0u, caret), fontSize);
     const Color caretColor = ResolveColorToken(
         state.activeTheme,
@@ -1709,6 +1882,7 @@ void DrawTextAreaNode(RuntimeBuildContext& state, const DemoNode& node, UIDrawLi
     const std::string placeholder = GetNodeAttribute(node, "placeholder");
     const bool showingPlaceholder = value.empty() && !placeholder.empty();
     const std::vector<std::string> lines = SplitLines(showingPlaceholder ? placeholder : value);
+    const float gutterWidth = ResolveTextAreaGutterWidth(node, (std::max)(std::size_t(1u), lines.size()), fontSize);
     const Color textColor = showingPlaceholder
         ? ResolveColorToken(state.activeTheme, "color.text.placeholder", Color(0.49f, 0.56f, 0.64f, 1.0f))
         : GetColorProperty(
@@ -1717,12 +1891,33 @@ void DrawTextAreaNode(RuntimeBuildContext& state, const DemoNode& node, UIDrawLi
               state.styleSheet,
               Style::UIStylePropertyId::ForegroundColor,
               Color(0.92f, 0.94f, 0.97f, 1.0f));
+    const Color lineNumberColor = ResolveColorToken(
+        state.activeTheme,
+        "color.text.secondary",
+        Color(0.74f, 0.78f, 0.86f, 1.0f));
+
+    if (gutterWidth > 0.0f) {
+        const float separatorX = contentRect.x + gutterWidth - kTextAreaLineNumberGap * 0.4f;
+        drawList.AddFilledRect(
+            UIRect(separatorX, contentRect.y, 1.0f, contentRect.height),
+            ToUIColor(ResolveColorToken(state.activeTheme, "color.outline", Color(0.23f, 0.29f, 0.35f, 1.0f))),
+            0.0f);
+    }
 
     for (std::size_t lineIndex = 0u; lineIndex < lines.size(); ++lineIndex) {
+        if (gutterWidth > 0.0f) {
+            drawList.AddText(
+                UIPoint(
+                    contentRect.x,
+                    contentRect.y + kTextInputTextInset + static_cast<float>(lineIndex) * lineHeight),
+                std::to_string(static_cast<unsigned long long>(lineIndex + 1u)),
+                ToUIColor(lineNumberColor),
+                fontSize * 0.9f);
+        }
         drawList.AddText(
             UIPoint(
-                contentRect.x + 2.0f,
-                contentRect.y + 2.0f + static_cast<float>(lineIndex) * lineHeight),
+                contentRect.x + kTextInputTextInset + gutterWidth,
+                contentRect.y + kTextInputTextInset + static_cast<float>(lineIndex) * lineHeight),
             lines[lineIndex].empty() ? std::string(" ") : lines[lineIndex],
             ToUIColor(textColor),
             fontSize);
@@ -1746,7 +1941,8 @@ void DrawTextAreaNode(RuntimeBuildContext& state, const DemoNode& node, UIDrawLi
 
     const float caretX =
         contentRect.x +
-        2.0f +
+        kTextInputTextInset +
+        gutterWidth +
         MeasureGlyphRunWidth(value.substr(lineStart, caret - lineStart), fontSize);
     const float caretY = contentRect.y + 3.0f + static_cast<float>(lineIndex) * lineHeight;
     const Color caretColor = ResolveColorToken(
@@ -2088,6 +2284,7 @@ const XCUIDemoFrameResult& XCUIDemoRuntime::Update(const XCUIDemoInputState& inp
             event.pointerButton == UI::UIPointerButton::Left) {
             if (state.armedElementId != 0u &&
                 hoveredPath.Target() == state.armedElementId) {
+                SetTextInputCaretFromPoint(state, hoveredPath.Target(), event.position);
                 ActivateNode(state, hoveredPath.Target());
             }
             state.armedElementId = 0u;
@@ -2120,7 +2317,12 @@ const XCUIDemoFrameResult& XCUIDemoRuntime::Update(const XCUIDemoInputState& inp
         }
 
         if (event.type == UIInputEventType::KeyDown) {
-            if (HandleTextInputKeyDown(state, focusedElementId, event.keyCode)) {
+            const UI::UIInputModifiers inputModifiers = event.modifiers;
+            if (HandleTextInputKeyDown(
+                    state,
+                    focusedElementId,
+                    event.keyCode,
+                    inputModifiers)) {
                 return;
             }
         }
diff --git a/tests/NewEditor/test_xcui_demo_runtime.cpp b/tests/NewEditor/test_xcui_demo_runtime.cpp
index c8502e97..1253dbfa 100644
--- a/tests/NewEditor/test_xcui_demo_runtime.cpp
+++ b/tests/NewEditor/test_xcui_demo_runtime.cpp
@@ -38,11 +38,21 @@ UIInputEvent MakeCharacterEvent(std::uint32_t character) {
     return event;
 }
 
-UIInputEvent MakeKeyDownEvent(XCEngine::Input::KeyCode keyCode, bool repeat = false) {
+UIInputEvent MakeKeyDownEvent(
+    XCEngine::Input::KeyCode keyCode,
+    bool repeat = false,
+    bool shift = false,
+    bool control = false,
+    bool alt = false,
+    bool super = false) {
     UIInputEvent event = {};
     event.type = UIInputEventType::KeyDown;
     event.keyCode = static_cast<std::int32_t>(keyCode);
     event.repeat = repeat;
+    event.modifiers.shift = shift;
+    event.modifiers.control = control;
+    event.modifiers.alt = alt;
+    event.modifiers.super = super;
     return event;
 }
 
@@ -372,17 +382,43 @@ TEST(NewEditorXCUIDemoRuntimeTest, TextAreaAcceptsMultilineInputAndCaretMovement
     ASSERT_TRUE(typedFrame.stats.documentsReady);
     EXPECT_EQ(typedFrame.stats.focusedElementId, "sessionNotes");
     EXPECT_EQ(typedFrame.stats.lastCommandId, "demo.text.edit.sessionNotes");
+    EXPECT_NE(FindTextCommand(typedFrame.drawData, "1"), nullptr);
+    EXPECT_NE(FindTextCommand(typedFrame.drawData, "2"), nullptr);
     EXPECT_NE(FindTextCommand(typedFrame.drawData, "OK"), nullptr);
     EXPECT_NE(FindTextCommand(typedFrame.drawData, "X"), nullptr);
 
+    XCEngine::Editor::XCUIBackend::XCUIDemoInputState tabInput = BuildInputState();
+    tabInput.events.push_back(MakeKeyDownEvent(XCEngine::Input::KeyCode::Home));
+    tabInput.events.push_back(MakeKeyDownEvent(XCEngine::Input::KeyCode::Tab));
+    const auto& indentedFrame = runtime.Update(tabInput);
+
+    ASSERT_TRUE(indentedFrame.stats.documentsReady);
+    EXPECT_EQ(indentedFrame.stats.focusedElementId, "sessionNotes");
+    EXPECT_EQ(indentedFrame.stats.lastCommandId, "demo.text.edit.sessionNotes");
+
+    const XCEngine::UI::UIPoint firstLineStart(
+        notesRect.x + 8.0f,
+        notesRect.y + 10.0f);
+
+    XCEngine::Editor::XCUIBackend::XCUIDemoInputState caretPressed = BuildInputState();
+    caretPressed.pointerPosition = firstLineStart;
+    caretPressed.pointerPressed = true;
+    caretPressed.pointerDown = true;
+    runtime.Update(caretPressed);
+
+    XCEngine::Editor::XCUIBackend::XCUIDemoInputState caretReleased = BuildInputState();
+    caretReleased.pointerPosition = firstLineStart;
+    caretReleased.pointerReleased = true;
+    const auto& caretFrame = runtime.Update(caretReleased);
+
+    ASSERT_TRUE(caretFrame.stats.documentsReady);
+    EXPECT_EQ(caretFrame.stats.focusedElementId, "sessionNotes");
+
     XCEngine::Editor::XCUIBackend::XCUIDemoInputState caretInput = BuildInputState();
-    caretInput.events.push_back(MakeKeyDownEvent(XCEngine::Input::KeyCode::Up));
-    caretInput.events.push_back(MakeKeyDownEvent(XCEngine::Input::KeyCode::End));
     caretInput.events.push_back(MakeCharacterEvent('!'));
     const auto& editedFrame = runtime.Update(caretInput);
 
     ASSERT_TRUE(editedFrame.stats.documentsReady);
-    EXPECT_NE(FindTextCommand(editedFrame.drawData, "OK!"), nullptr);
-    EXPECT_NE(FindTextCommand(editedFrame.drawData, "X"), nullptr);
+    EXPECT_NE(FindTextCommand(editedFrame.drawData, "!OK"), nullptr);
     EXPECT_EQ(editedFrame.stats.focusedElementId, "sessionNotes");
 }
diff --git a/tests/editor/CMakeLists.txt b/tests/editor/CMakeLists.txt
index 8d2e8e61..1cd6d545 100644
--- a/tests/editor/CMakeLists.txt
+++ b/tests/editor/CMakeLists.txt
@@ -28,6 +28,8 @@ set(EDITOR_TEST_SOURCES
     test_viewport_object_id_picker.cpp
     test_viewport_render_targets.cpp
     test_viewport_render_flow_utils.cpp
+    test_imgui_backend_bridge_api.cpp
+    test_window_renderer_api.cpp
     test_builtin_icon_layout_utils.cpp
     test_xcui_draw_data.cpp
     test_xcui_imgui_transition_backend.cpp
diff --git a/tests/editor/test_editor_console_sink.cpp b/tests/editor/test_editor_console_sink.cpp
new file mode 100644
index 00000000..ec6b7ffd
--- /dev/null
+++ b/tests/editor/test_editor_console_sink.cpp
@@ -0,0 +1,22 @@
+#include <gtest/gtest.h>
+
+#include "Core/EditorConsoleSink.h"
+
+namespace XCEngine::Debug {
+namespace {
+
+TEST(EditorConsoleSink, GetInstanceTracksRegisteredSinkOnly) {
+    EditorConsoleSink* registeredInstance = nullptr;
+
+    {
+        EditorConsoleSink sink;
+        registeredInstance = &sink;
+
+        EXPECT_EQ(EditorConsoleSink::GetInstance(), registeredInstance);
+    }
+
+    EXPECT_EQ(EditorConsoleSink::GetInstance(), nullptr);
+}
+
+} // namespace
+} // namespace XCEngine::Debug
diff --git a/tests/editor/test_imgui_backend_bridge_api.cpp b/tests/editor/test_imgui_backend_bridge_api.cpp
new file mode 100644
index 00000000..a5138f22
--- /dev/null
+++ b/tests/editor/test_imgui_backend_bridge_api.cpp
@@ -0,0 +1,40 @@
+#include <gtest/gtest.h>
+
+#include "UI/ImGuiBackendBridge.h"
+
+#include <type_traits>
+
+namespace {
+
+using XCEngine::Editor::UI::ImGuiBackendBridge;
+using XCEngine::RHI::RHIDevice;
+using XCEngine::RHI::RHIResourceView;
+using XCEngine::RHI::RHITexture;
+
+TEST(ImGuiBackendBridgeApiTest, ExposesExistingShaderResourceViewRegistrationOverload) {
+    using TextureDescriptorFromTextureSignature = bool (ImGuiBackendBridge::*)(
+        RHIDevice*,
+        RHITexture*,
+        D3D12_CPU_DESCRIPTOR_HANDLE*,
+        D3D12_GPU_DESCRIPTOR_HANDLE*,
+        ImTextureID*);
+    using TextureDescriptorFromSrvSignature = bool (ImGuiBackendBridge::*)(
+        RHIDevice*,
+        RHIResourceView*,
+        D3D12_CPU_DESCRIPTOR_HANDLE*,
+        D3D12_GPU_DESCRIPTOR_HANDLE*,
+        ImTextureID*);
+
+    static_assert(std::is_same_v<
+                  decltype(static_cast<TextureDescriptorFromTextureSignature>(
+                      &ImGuiBackendBridge::CreateTextureDescriptor)),
+                  TextureDescriptorFromTextureSignature>);
+    static_assert(std::is_same_v<
+                  decltype(static_cast<TextureDescriptorFromSrvSignature>(
+                      &ImGuiBackendBridge::CreateTextureDescriptor)),
+                  TextureDescriptorFromSrvSignature>);
+
+    SUCCEED();
+}
+
+} // namespace
diff --git a/tests/editor/test_window_renderer_api.cpp b/tests/editor/test_window_renderer_api.cpp
new file mode 100644
index 00000000..a69e1e42
--- /dev/null
+++ b/tests/editor/test_window_renderer_api.cpp
@@ -0,0 +1,28 @@
+#include <gtest/gtest.h>
+
+#include "Platform/D3D12WindowRenderer.h"
+
+#include <type_traits>
+
+namespace {
+
+using XCEngine::Editor::Platform::D3D12WindowRenderer;
+using XCEngine::Rendering::RenderSurface;
+
+TEST(D3D12WindowRendererApiTest, ExposesSurfaceAwareRenderCallbackAndAccessor) {
+    using Callback = D3D12WindowRenderer::RenderCallback;
+
+    static_assert(std::is_same_v<
+                  decltype(std::declval<D3D12WindowRenderer&>().GetCurrentRenderSurface()),
+                  const RenderSurface*>);
+    static_assert(std::is_same_v<
+                  decltype(std::declval<D3D12WindowRenderer&>().Render(
+                      std::declval<::XCEngine::Editor::UI::ImGuiBackendBridge&>(),
+                      std::declval<const float*>(),
+                      std::declval<const Callback&>())),
+                  void>);
+
+    SUCCEED();
+}
+
+} // namespace