diff --git a/B07_wf4_DesignDetail/B07_wf4_DesignDetail_UI_CadViewer.ts b/B07_wf4_DesignDetail/B07_wf4_DesignDetail_UI_CadViewer.ts
index 212b8149..8da75bbc 100644
--- a/B07_wf4_DesignDetail/B07_wf4_DesignDetail_UI_CadViewer.ts
+++ b/B07_wf4_DesignDetail/B07_wf4_DesignDetail_UI_CadViewer.ts
@@ -11,6 +11,7 @@
 
 import { AcApDocManager } from "@mlightcad/cad-simple-viewer";
 import {
+  acdbHostApplicationServices,
   AcCmColor,
   AcDbLayerTableRecord,
   AcDbLine,
@@ -113,7 +114,14 @@ export function mountPocCadViewer(host: HTMLElement, drawing: CadDrawingJson): n
   if (!drawingLoaded) {
     appended = loadDrawingIntoDatabase(manager, drawing);
     drawingLoaded = true;
+
+    // 파일 오픈 흐름이 아니므로 layoutSwitched 이벤트를 직접 발화해야
+    // 뷰가 레이아웃 뷰 생성·가시화·초기 줌을 수행한다 (미발화 시 빈 화면).
+    const db = manager.curDocument.database;
+    const modelSpaceBtrId = db.tables.blockTable.modelSpace.objectId;
+    manager.setActiveLayout();
+    acdbHostApplicationServices().layoutManager.setCurrentLayoutBtrId(modelSpaceBtrId, db);
+    manager.curView.zoomToFitDrawing();
   }
-  manager.curView.zoomToFitDrawing();
   return appended;
 }
diff --git a/B07_wf4_DesignDetail/B07_wf4_DesignDetail_UI_Page.ts b/B07_wf4_DesignDetail/B07_wf4_DesignDetail_UI_Page.ts
index a2c104ef..687c4d47 100644
--- a/B07_wf4_DesignDetail/B07_wf4_DesignDetail_UI_Page.ts
+++ b/B07_wf4_DesignDetail/B07_wf4_DesignDetail_UI_Page.ts
@@ -1,10 +1,12 @@
 /* =============================================================================
  * B07_wf4_DesignDetail_UI_Page.ts
- * 로그인 후 07: 4차 워크플로우 (상세 설계) — WebCAD PoC
+ * 로그인 후 07: 4차 워크플로우 (상세 설계) — WebCAD 전체 앱 임베드
  *
- * 레이아웃 (PLAN.md WebCAD 사용자 지시):
- *   - 사이드 패널: 빈 상태 유지 (B06→B07 전달 데이터 스펙 미확정)
- *   - 상세 페이지 영역: CAD 뷰어 (서버 기하 JSON 렌더링, DXF 파싱 없음)
+ * 방향 전환 (PLAN.md 2026-07-19): 코어 조립이 아니라 완성된 오픈소스 CAD 앱
+ * (external_program/cad-viewer-example, GPL 워커 제외 빌드)을 /cadviewer 정적
+ * 경로로 서빙하고 iframe으로 임베드한다. 데이터 연동은 후속 단계.
+ *
+ * 레이아웃 (사용자 지시): 사이드 패널 빈 상태 유지 + 상세 영역 CAD 화면.
  * 제약 준수 (frontend.md §2 3단 레이아웃): createWorkflowLayout 재사용.
  * ========================================================================== */
 
@@ -19,8 +21,9 @@ import {
   WORKFLOW_STEP_ROUTES,
   type WorkflowState,
 } from "../A00_Common/b_workflow_nav";
-import { fetchPocSampleDrawing } from "./B07_wf4_DesignDetail_Api_Fetch";
-import { mountPocCadViewer } from "./B07_wf4_DesignDetail_UI_CadViewer";
+
+/** WebCAD 전체 앱 정적 경로 (main.py /cadviewer 마운트, dev는 vite proxy 위임) */
+const CAD_VIEWER_APP_URL = "/cadviewer/index.html";
 
 /** locale 헬퍼 */
 function L(key: keyof typeof ui_locales): string {
@@ -57,10 +60,11 @@ export async function renderB07DesignDetail(root: HTMLElement): Promise<void> {
 
   const cadHost = document.createElement("div");
   cadHost.className = "b07-cad-host";
-  const status = document.createElement("div");
-  status.className = "b07-cad-status";
-  status.textContent = L("B07_Cad_Loading");
-  cadHost.append(status);
+  const frame = document.createElement("iframe");
+  frame.className = "b07-cad-frame";
+  frame.src = CAD_VIEWER_APP_URL;
+  frame.title = L("B07_Design_Title");
+  cadHost.append(frame);
 
   const layout = createWorkflowLayout({
     title: L("B07_Design_Title"),
@@ -77,14 +81,4 @@ export async function renderB07DesignDetail(root: HTMLElement): Promise<void> {
   });
   layout.root.classList.add("b07-design-layout");
   root.replaceChildren(layout.root);
-
-  try {
-    const drawing = await fetchPocSampleDrawing();
-    mountPocCadViewer(cadHost, drawing);
-    status.remove();
-  } catch (error) {
-    status.textContent = `${L("B07_Cad_Load_Failed")} ${
-      error instanceof Error ? error.message : ""
-    }`.trim();
-  }
 }
diff --git a/B07_wf4_DesignDetail/B07_wf4_DesignDetail_UI_Style.css b/B07_wf4_DesignDetail/B07_wf4_DesignDetail_UI_Style.css
index f4b810af..9b60f03d 100644
--- a/B07_wf4_DesignDetail/B07_wf4_DesignDetail_UI_Style.css
+++ b/B07_wf4_DesignDetail/B07_wf4_DesignDetail_UI_Style.css
@@ -61,6 +61,15 @@
   display: block;
 }
 
+/* WebCAD 전체 앱 임베드 (iframe) */
+.b07-cad-frame {
+  position: absolute;
+  inset: 0;
+  width: 100%;
+  height: 100%;
+  border: 0;
+}
+
 /* 로딩·오류 상태 메시지 */
 .b07-cad-status {
   position: absolute;
diff --git a/external_program/cad-viewer b/external_program/cad-viewer
new file mode 160000
index 00000000..7b9a8084
--- /dev/null
+++ b/external_program/cad-viewer
@@ -0,0 +1 @@
+Subproject commit 7b9a8084d7b048b7000aa178ae78109d84078cb0
diff --git a/external_program/cad-viewer-example b/external_program/cad-viewer-example
new file mode 160000
index 00000000..482a061c
--- /dev/null
+++ b/external_program/cad-viewer-example
@@ -0,0 +1 @@
+Subproject commit 482a061c4462dde0fd7b1d10c9242932e09b4e56
diff --git a/main.py b/main.py
index 0a90c515..ec23e102 100644
--- a/main.py
+++ b/main.py
@@ -223,6 +223,15 @@ app.mount(
 )
 logger.info(f"✓ 정적 파일 서빙 경로 등록: {STATIC_URL} → {STATIC_DIR}")
 
+# WebCAD 전체 앱 (external_program/cad-viewer-example 빌드본, GPL 워커 제외) — B07 iframe용
+CADVIEWER_DIST_DIR = str(Path(__file__).parent / "external_program" / "cad-viewer-example" / "dist")
+app.mount(
+    "/cadviewer",
+    StaticFiles(directory=CADVIEWER_DIST_DIR, html=True, check_dir=False),
+    name="cadviewer",
+)
+logger.info(f"✓ WebCAD 정적 서빙 경로 등록: /cadviewer → {CADVIEWER_DIST_DIR}")
+
 # ─────────────────────────────────────────────────────────────────────────
 # 기본 엔드포인트
 # ─────────────────────────────────────────────────────────────────────────
diff --git a/scratch/test_vworld_download.py b/scratch/test_vworld_download.py
new file mode 100644
index 00000000..33c78b47
--- /dev/null
+++ b/scratch/test_vworld_download.py
@@ -0,0 +1,56 @@
+import sys
+import traceback
+from pathlib import Path
+import numpy as np
+
+# Add project root to sys.path
+PROJECT_ROOT = Path(__file__).resolve().parent.parent
+sys.path.insert(0, str(PROJECT_ROOT))
+
+from B04_wf1_Surface.B04_wf1_Surface_Engine_VWorld import download_vworld_satellite_map
+from B04_wf1_Surface.B04_wf1_Surface_Engine_GisVector import download_all_gis_vectors
+
+PRJ_PATH = PROJECT_ROOT / "storage/1/3/acb9170b-9ac8-49b3-82a0-51cfa32bb42d/B03_FileInput/input/prj/result.prj"
+NPZ_PATH = PROJECT_ROOT / "storage/1/3/acb9170b-9ac8-49b3-82a0-51cfa32bb42d/B04_wf1_Surface/processed/ground_points_csf.npz"
+OUTPUT_DIR = PROJECT_ROOT / "storage/1/3/acb9170b-9ac8-49b3-82a0-51cfa32bb42d/B04_wf1_Surface/processed"
+
+def main():
+    print("Loading NPZ to get bounds...")
+    with np.load(NPZ_PATH) as data:
+        bounds = data["bounds"]
+        print("Raw bounds:", bounds)
+        
+    bounds_dict = {
+        "x": [float(bounds[0, 0]), float(bounds[0, 1])],
+        "y": [float(bounds[1, 0]), float(bounds[1, 1])],
+        "z": [float(bounds[2, 0]), float(bounds[2, 1])],
+    }
+    
+    print("\n--- Test 1: VWorld Satellite Map Download ---")
+    try:
+        res = download_vworld_satellite_map(
+            prj_path=PRJ_PATH,
+            bounds=bounds_dict,
+            output_dir=OUTPUT_DIR,
+            layer_name="Satellite",
+            ext="jpeg"
+        )
+        print("Download Result:", res)
+    except Exception as e:
+        print("VWorld Download Failed:")
+        traceback.print_exc()
+
+    print("\n--- Test 2: GIS Vector Download ---")
+    try:
+        download_all_gis_vectors(
+            prj_path=PRJ_PATH,
+            bounds_meter=bounds_dict,
+            output_dir=OUTPUT_DIR
+        )
+        print("GIS Vector Download completed.")
+    except Exception as e:
+        print("GIS Download Failed:")
+        traceback.print_exc()
+
+if __name__ == "__main__":
+    main()
diff --git a/ui_template/ui_template_theme.css b/ui_template/ui_template_theme.css
index 20729992..0b1c33ec 100644
--- a/ui_template/ui_template_theme.css
+++ b/ui_template/ui_template_theme.css
@@ -170,6 +170,12 @@
   --card-padding: 24px;
   --element-gap: 8px;
 
+  /* Scrollbar */
+  --color-scrollbar-track: color-mix(in srgb, var(--color-text) 9%, transparent);
+  --color-scrollbar-thumb: color-mix(in srgb, var(--color-text) 38%, transparent);
+  --color-scrollbar-thumb-hover: color-mix(in srgb, var(--color-text) 56%, transparent);
+  --color-scrollbar-thumb-active: color-mix(in srgb, var(--color-text) 72%, transparent);
+
   /* 워크플로우 3단 레이아웃 (frontend.md §2) */
   --wf-header-height: 56px; /* 상단: 타이틀 + 진행 단계 */
   --wf-left-panel-width: 320px; /* 좌측: 입력 폼 (너비 고정) */
@@ -271,6 +277,44 @@
   box-sizing: border-box;
 }
 
+/* Keep the platform scrollbar footprint while giving every scroll container a
+ * consistent translucent treatment. Width/height are intentionally untouched. */
+* {
+  scrollbar-color: var(--color-scrollbar-thumb) var(--color-scrollbar-track);
+  scrollbar-width: auto;
+}
+
+@supports selector(::-webkit-scrollbar) {
+  * {
+    scrollbar-color: auto;
+  }
+
+  *::-webkit-scrollbar-track {
+    background-color: var(--color-scrollbar-track);
+  }
+
+  *::-webkit-scrollbar-thumb {
+    border: 3px solid transparent;
+    border-radius: var(--radius-pills);
+    background-color: var(--color-scrollbar-thumb);
+    background-clip: padding-box;
+  }
+
+  *::-webkit-scrollbar-thumb:hover {
+    background-color: var(--color-scrollbar-thumb-hover);
+  }
+
+  *::-webkit-scrollbar-thumb:active {
+    background-color: var(--color-scrollbar-thumb-active);
+  }
+}
+
+@media (forced-colors: active) {
+  * {
+    scrollbar-color: auto;
+  }
+}
+
 html,
 body {
   margin: 0;
diff --git a/vite.config.ts b/vite.config.ts
index 9d390bf8..7c4194c1 100644
--- a/vite.config.ts
+++ b/vite.config.ts
@@ -41,6 +41,11 @@ export default {
         target: "http://localhost:8000",
         changeOrigin: true,
       },
+      // WebCAD 전체 앱 (B07 iframe) — FastAPI 정적 마운트로 위임
+      "/cadviewer": {
+        target: "http://localhost:8000",
+        changeOrigin: true,
+      },
     },
   },
   build: {