diff --git a/specs/numerical_design_system.md b/specs/numerical_design_system.md
index 6707cee..ccfb544 100644
--- a/specs/numerical_design_system.md
+++ b/specs/numerical_design_system.md
@@ -1,7 +1,7 @@
 # Numerical Design & Balancing System (NDBS) - Implementation Guide
 
-**Version:** 2.0 (AI-Actionable)
-**Target Stack:** Python (FastAPI), Vue.js (Vite), C# (Godot .NET)
+**Version:** 2.0 
+**Target Stack:** Python 3.14 (FastAPI, uv), Vue.js (Vite), C# (Godot .NET)
 **Role:** AI Developer Guide
 
 ## 1. System Overview
@@ -13,32 +13,40 @@ This guide is structured as a sequence of tasks for an AI agent to implement the
 
 ---
 
-## 2. Directory Structure Plan
-The tool will reside in a new `tools/ndbs/` directory, keeping it separate from the game assets but with access to them.
+## 2. Architecture
 
-```text
-D:\code\super-mentor\
-├── resources\definitions\      <-- Target Data Source
-├── scripts\Rules\Generated\    <-- Target Script Output
-├── tools\
-│   └── ndbs\
-│       ├── server\             <-- Python Backend
-│       │   ├── main.py
-│       │   └── ...
-│       └── client\             <-- Vue Frontend
-│           ├── src\
-│           └── ...
+The system is designed as a **Unified Web Service**. A single Python process handles both the API logic and serving the frontend interface.
+
+1.  **NDBS Service (Python/FastAPI):**
+    *   **API Layer:** Handles data reading/writing and script generation (`/api/*`).
+    *   **Static Layer:** Serves the compiled Vue.js application (`index.html`, `js/`, `css/`) from the `client/dist` directory.
+2.  **NDBS Web Client (Vue.js):**
+    *   Developed as a standard SPA.
+    *   Built into static files (`npm run build`) which are consumed by the Python service.
+
+**Runtime Flow:**
+User runs `python main.py` -> Browser opens `http://localhost:8000` -> Frontend loads -> Frontend calls `/api/...` -> Python modifies files.
+
+```mermaid
+graph TD
+    User[Designer] -->|Browser| Service[NDBS Python Service]
+    Service -->|Serve Static| Frontend[Vue.js UI]
+    Service -->|API| Logic[Business Logic]
+    Logic -->|Read/Write| JSON[JSON/TRES Definitions]
+    Logic -->|Generate| CSharp[C# Rule Scripts]
 ```
 
 ---
 
-## 3. Implementation Phases (AI Prompts)
+## 3. Implementation Phases
 
 ### Phase 1: Python Backend Foundation
 **Goal:** Establish a FastAPI server that can read/write the game's JSON files.
 
 **Step 1.1: Environment Setup**
-*   **Instruction:** Create `tools/ndbs/server/`. Initialize a Python environment. Install `fastapi`, `uvicorn`, `pydantic`.
+*   **Instruction:** Create `tools/ndbs/server/`. Initialize a Python environment using `uv`.
+    *   Run `uv init --python 3.14` to set up the project.
+    *   Run `uv add fastapi uvicorn pydantic` to install dependencies.
 *   **Code Requirement:** Create `tools/ndbs/server/main.py`.
 *   **Key Functionality:**
     *   Enable CORS (allow all origins for dev).
@@ -58,6 +66,11 @@ D:\code\super-mentor\
 **Step 1.3: Schema Inference (Dynamic Models)**
 *   **Instruction:** Since we don't have hardcoded Pydantic models for every file, create a utility that reads a file (JSON or TRES) and generates a generic "Schema" description (listing keys and value types) to help the frontend build forms dynamically.
 
+**Step 1.4: Static Asset Serving (SPA Support)**
+*   **Instruction:** Configure FastAPI to serve the frontend.
+    *   Mount the `client/dist` directory to `/` as static files.
+    *   **Critical:** Implement a "Catch-All" route (after API routes) that returns `client/dist/index.html`. This ensures that Vue Router paths (e.g., `http://localhost:8000/editor/archetypes`) work when refreshed.
+
 ---
 
 
@@ -65,7 +78,7 @@ D:\code\super-mentor\
 **Goal:** A clean UI to browse files and edit JSON data.
 
 **Step 2.1: Project Scaffolding**
-*   **Instruction:** Create `tools/ndbs/client` using Vite + Vue 3 (TypeScript). Install `axios`, `pinia` (state management), and `naive-ui` (or `element-plus`) for UI components.
+*   **Instruction:** Create `tools/ndbs/client` using Vite + Vue 3 (TypeScript). Install `axios`, `pinia`, and `naive-ui`.
 
 **Step 2.2: File Explorer & Layout**
 *   **Instruction:** Create a standard "Sidebar + Main Content" layout.
@@ -75,9 +88,13 @@ D:\code\super-mentor\
 **Step 2.3: Generic JSON Editor**
 *   **Instruction:** Create a component `JsonEditor.vue`.
     *   Fetch content using `GET /api/files/content`.
-    *   Display the raw JSON in a textarea (Monaco Editor preferred later, start simple).
+    *   Display the raw JSON in a textarea (Monaco Editor preferred later).
     *   Add a "Save" button that calls `POST /api/files/content`.
-    *   **Enhancement:** Use a library like `jsoneditor` or `v-jsoneditor` to provide a tree view/form view.
+
+**Step 2.4: Build Integration**
+*   **Instruction:** Configure `vite.config.ts` to output to `../server/client_dist` (or just `dist` inside client, and server reads from there).
+    *   Ensure the "Build" command produces the artifacts expected by Step 1.4.
+
 
 ---
 
@@ -143,11 +160,10 @@ D:\code\super-mentor\
 
 ### 4.1 File Paths
 *   **Server Root:** `tools/ndbs/server`
-*   **Client Root:** `tools/ndbs/client`
 *   **Game Root:** `../../` (Relative to server)
 
 ### 4.2 Coding Style
-*   **Python:** Type hints (Python 3.10+), Pydantic models for request/response bodies.
+*   **Python:** Type hints (Python 3.14), Pydantic models for request/response bodies. Use `uv` for dependency management.
 *   **Vue:** Composition API (`<script setup lang="ts">`), Scoped CSS.
 *   **C#:** Namespace `Rules.Generated` for all generated scripts.
 
diff --git a/tools/ndbs/server/main.py b/tools/ndbs/server/main.py
new file mode 100644
index 0000000..0e1ca5c
--- /dev/null
+++ b/tools/ndbs/server/main.py
@@ -0,0 +1,214 @@
+from __future__ import annotations
+
+import os
+import subprocess
+from typing import Any, Dict, List, Optional
+
+from fastapi import APIRouter, Depends, FastAPI, HTTPException, Query, Request
+from fastapi.middleware.cors import CORSMiddleware
+from fastapi.responses import FileResponse
+from fastapi.staticfiles import StaticFiles
+from pydantic import BaseModel
+
+from ndbs_core import (
+    ALLOWED_DEFINITION_EXTS,
+    ALLOWED_RULE_EXTS,
+    NdbsPaths,
+    create_rule as core_create_rule,
+    ensure_within_root,
+    infer_schema,
+    list_definition_files,
+    list_rule_files,
+    load_definition_file,
+    resolve_paths,
+    write_definition_file,
+)
+
+
+class FileContentRequest(BaseModel):
+    filename: str
+    content: Any
+
+
+class RuleCreateRequest(BaseModel):
+    rule_id: str
+
+
+class RuleContentRequest(BaseModel):
+    filename: str
+    content: str
+
+
+api_router = APIRouter()
+ui_router = APIRouter()
+
+
+def get_paths(request: Request) -> NdbsPaths:
+    return request.app.state.paths
+
+
+def create_app(paths: Optional[NdbsPaths] = None) -> FastAPI:
+    app = FastAPI(title="NDBS Server")
+    app.add_middleware(
+        CORSMiddleware,
+        allow_origins=["*"],
+        allow_credentials=True,
+        allow_methods=["*"],
+        allow_headers=["*"],
+    )
+    resolved_paths = paths or resolve_paths()
+    app.state.paths = resolved_paths
+    if resolved_paths.web_root.exists():
+        app.mount(
+            "/static",
+            StaticFiles(directory=str(resolved_paths.web_root)),
+            name="static",
+        )
+    app.include_router(ui_router)
+    app.include_router(api_router, prefix="/api")
+    return app
+
+
+@ui_router.get("/")
+def serve_index(paths: NdbsPaths = Depends(get_paths)) -> FileResponse:
+    index_path = paths.web_root / "index.html"
+    if not index_path.exists():
+        raise HTTPException(status_code=500, detail="UI assets are missing.")
+    return FileResponse(index_path)
+
+
+@api_router.get("/files/definitions")
+def list_definitions(paths: NdbsPaths = Depends(get_paths)) -> Dict[str, List[str]]:
+    try:
+        files = list_definition_files(paths)
+    except FileNotFoundError:
+        raise HTTPException(status_code=500, detail="Definitions root not found.")
+    return {"files": files}
+
+
+@api_router.get("/files/content")
+def get_file_content(
+    filename: str = Query(...),
+    paths: NdbsPaths = Depends(get_paths),
+) -> Dict[str, Any]:
+    try:
+        path = ensure_within_root(paths.definitions_root, filename, ALLOWED_DEFINITION_EXTS)
+    except ValueError as exc:
+        raise HTTPException(status_code=400, detail=str(exc))
+    if not path.exists():
+        raise HTTPException(status_code=404, detail="File not found.")
+    try:
+        content = load_definition_file(path)
+    except ValueError as exc:
+        raise HTTPException(status_code=400, detail=str(exc))
+    return {"filename": filename, "content": content}
+
+
+@api_router.post("/files/content")
+def save_file_content(
+    payload: FileContentRequest,
+    paths: NdbsPaths = Depends(get_paths),
+) -> Dict[str, str]:
+    try:
+        path = ensure_within_root(
+            paths.definitions_root, payload.filename, ALLOWED_DEFINITION_EXTS
+        )
+    except ValueError as exc:
+        raise HTTPException(status_code=400, detail=str(exc))
+    if not path.exists():
+        raise HTTPException(status_code=404, detail="File not found.")
+    try:
+        write_definition_file(path, payload.content, paths)
+    except ValueError as exc:
+        raise HTTPException(status_code=400, detail=str(exc))
+    return {"status": "ok"}
+
+
+@api_router.get("/files/schema")
+def get_file_schema(
+    filename: str = Query(...),
+    paths: NdbsPaths = Depends(get_paths),
+) -> Dict[str, Any]:
+    try:
+        path = ensure_within_root(paths.definitions_root, filename, ALLOWED_DEFINITION_EXTS)
+    except ValueError as exc:
+        raise HTTPException(status_code=400, detail=str(exc))
+    if not path.exists():
+        raise HTTPException(status_code=404, detail="File not found.")
+    content = load_definition_file(path)
+    return {"filename": filename, "schema": infer_schema(content)}
+
+
+@api_router.post("/rules/create")
+def create_rule(
+    payload: RuleCreateRequest,
+    paths: NdbsPaths = Depends(get_paths),
+) -> Dict[str, str]:
+    try:
+        filename = core_create_rule(payload.rule_id, paths)
+    except ValueError as exc:
+        raise HTTPException(status_code=400, detail=str(exc))
+    except FileExistsError:
+        raise HTTPException(status_code=409, detail="Rule already exists.")
+    return {"status": "ok", "filename": filename}
+
+
+@api_router.get("/rules/list")
+def list_rules(paths: NdbsPaths = Depends(get_paths)) -> Dict[str, List[str]]:
+    return {"files": list_rule_files(paths)}
+
+
+@api_router.get("/rules/content")
+def get_rule_content(
+    filename: str = Query(...),
+    paths: NdbsPaths = Depends(get_paths),
+) -> Dict[str, str]:
+    try:
+        path = ensure_within_root(paths.rules_root, filename, ALLOWED_RULE_EXTS)
+    except ValueError as exc:
+        raise HTTPException(status_code=400, detail=str(exc))
+    if not path.exists():
+        raise HTTPException(status_code=404, detail="Rule not found.")
+    return {"filename": filename, "content": path.read_text(encoding="utf-8")}
+
+
+@api_router.post("/rules/content")
+def save_rule_content(
+    payload: RuleContentRequest,
+    paths: NdbsPaths = Depends(get_paths),
+) -> Dict[str, str]:
+    try:
+        path = ensure_within_root(paths.rules_root, payload.filename, ALLOWED_RULE_EXTS)
+    except ValueError as exc:
+        raise HTTPException(status_code=400, detail=str(exc))
+    if not path.exists():
+        raise HTTPException(status_code=404, detail="Rule not found.")
+    path.write_text(payload.content, encoding="utf-8")
+    return {"status": "ok"}
+
+
+@api_router.post("/build")
+def build_game(paths: NdbsPaths = Depends(get_paths)) -> Dict[str, Any]:
+    if os.getenv("NDBS_DISABLE_BUILD") == "1":
+        raise HTTPException(status_code=503, detail="Build disabled.")
+    result = subprocess.run(
+        ["dotnet", "build"],
+        cwd=str(paths.project_root),
+        capture_output=True,
+        text=True,
+        check=False,
+    )
+    return {
+        "success": result.returncode == 0,
+        "stdout": result.stdout,
+        "stderr": result.stderr,
+    }
+
+
+app = create_app()
+
+
+if __name__ == "__main__":
+    import uvicorn
+
+    uvicorn.run("main:app", host="127.0.0.1", port=8000, reload=True)
diff --git a/tools/ndbs/server/ndbs_core.py b/tools/ndbs/server/ndbs_core.py
new file mode 100644
index 0000000..d452767
--- /dev/null
+++ b/tools/ndbs/server/ndbs_core.py
@@ -0,0 +1,353 @@
+from __future__ import annotations
+
+import json
+import os
+import re
+import shutil
+from dataclasses import dataclass
+from datetime import datetime, timezone
+from pathlib import Path
+from typing import Any, Dict, List, Optional
+
+ALLOWED_DEFINITION_EXTS = {".json", ".tres"}
+ALLOWED_RULE_EXTS = {".cs"}
+
+SECTION_RE = re.compile(r"^\s*\[(?P<name>[^]]+)\]\s*$")
+KEY_VALUE_RE = re.compile(r"^(?P<indent>\s*)(?P<key>[A-Za-z0-9_]+)\s*=\s*(?P<value>.+)$")
+
+
+@dataclass(frozen=True)
+class NdbsPaths:
+    project_root: Path
+    definitions_root: Path
+    rules_root: Path
+    backup_root: Path
+    web_root: Path
+
+
+def _find_project_root(start: Path) -> Path:
+    for candidate in [start] + list(start.parents):
+        if (candidate / "project.godot").exists():
+            return candidate
+    if len(start.parents) > 3:
+        return start.parents[3]
+    return start.parent
+
+
+def _env_path(name: str) -> Optional[Path]:
+    value = os.getenv(name)
+    if not value:
+        return None
+    return Path(value).expanduser().resolve()
+
+
+def resolve_paths() -> NdbsPaths:
+    server_root = Path(__file__).resolve().parent
+    project_root = _env_path("NDBS_PROJECT_ROOT") or _find_project_root(server_root)
+    definitions_root = _env_path("NDBS_DEFINITIONS_ROOT") or (
+        project_root / "resources" / "definitions"
+    )
+    rules_root = _env_path("NDBS_RULES_ROOT") or (
+        project_root / "scripts" / "Rules" / "Generated"
+    )
+    backup_root = _env_path("NDBS_BACKUP_ROOT") or (
+        project_root / "tools" / "ndbs" / "backups"
+    )
+    web_root = _env_path("NDBS_WEB_ROOT") or (server_root / "web")
+    return NdbsPaths(
+        project_root=project_root,
+        definitions_root=definitions_root,
+        rules_root=rules_root,
+        backup_root=backup_root,
+        web_root=web_root,
+    )
+
+
+def ensure_within_root(root: Path, filename: str, allowed_exts: set[str]) -> Path:
+    if not filename or Path(filename).is_absolute():
+        raise ValueError("Invalid filename.")
+    if Path(filename).suffix.lower() not in allowed_exts:
+        raise ValueError("Unsupported file type.")
+    target = (root / filename).resolve()
+    root_resolved = root.resolve()
+    if os.path.commonpath([str(root_resolved), str(target)]) != str(root_resolved):
+        raise ValueError("Path traversal is not allowed.")
+    return target
+
+
+def backup_file(path: Path, paths: NdbsPaths) -> None:
+    if not path.exists():
+        return
+    timestamp = datetime.now(timezone.utc).strftime("%Y%m%d_%H%M%S")
+    relative = path.relative_to(paths.project_root)
+    backup_path = paths.backup_root / timestamp / relative
+    backup_path.parent.mkdir(parents=True, exist_ok=True)
+    shutil.copy2(path, backup_path)
+
+
+def _unescape_tres_string(value: str) -> str:
+    if len(value) >= 2 and value[0] == "\"" and value[-1] == "\"":
+        value = value[1:-1]
+    return value.replace("\\\"", "\"").replace("\\\\", "\\")
+
+
+def _escape_tres_string(value: str) -> str:
+    return value.replace("\\", "\\\\").replace("\"", "\\\"")
+
+
+def _looks_like_expression(value: str) -> bool:
+    if value.startswith(("ExtResource(", "SubResource(", "Resource(")):
+        return True
+    return re.match(r"^[A-Za-z_][A-Za-z0-9_]*\(.+\)$", value) is not None
+
+
+def parse_tres_value(raw: str) -> Any:
+    raw = raw.strip()
+    if raw.startswith("[") and raw.endswith("]"):
+        return parse_tres_array(raw)
+    if raw.startswith("\"") and raw.endswith("\""):
+        return _unescape_tres_string(raw)
+    if raw in ("true", "false"):
+        return raw == "true"
+    if raw == "null":
+        return None
+    try:
+        if "." in raw or "e" in raw or "E" in raw:
+            return float(raw)
+        return int(raw)
+    except ValueError:
+        return raw
+
+
+def parse_tres_array(raw: str) -> List[Any]:
+    inner = raw[1:-1].strip()
+    if not inner:
+        return []
+    items: List[str] = []
+    current = ""
+    in_quotes = False
+    escape = False
+    for ch in inner:
+        if escape:
+            current += ch
+            escape = False
+            continue
+        if ch == "\\":
+            current += ch
+            escape = True
+            continue
+        if ch == "\"":
+            in_quotes = not in_quotes
+            current += ch
+            continue
+        if ch == "," and not in_quotes:
+            items.append(current.strip())
+            current = ""
+            continue
+        current += ch
+    if current.strip():
+        items.append(current.strip())
+    return [parse_tres_value(item) for item in items]
+
+
+def serialize_tres_value(value: Any) -> str:
+    if isinstance(value, bool):
+        return "true" if value else "false"
+    if isinstance(value, int):
+        return str(value)
+    if isinstance(value, float):
+        return str(value)
+    if value is None:
+        return "null"
+    if isinstance(value, list):
+        inner = ", ".join(serialize_tres_value(item) for item in value)
+        return f"[ {inner} ]"
+    if isinstance(value, str):
+        if _looks_like_expression(value):
+            return value
+        return f"\"{_escape_tres_string(value)}\""
+    return f"\"{_escape_tres_string(str(value))}\""
+
+
+def load_tres_resource(text: str) -> Dict[str, Any]:
+    lines = text.splitlines()
+    data: Dict[str, Any] = {}
+    in_resource = False
+    for line in lines:
+        section_match = SECTION_RE.match(line)
+        if section_match:
+            in_resource = section_match.group("name") == "resource"
+            continue
+        if not in_resource:
+            continue
+        kv_match = KEY_VALUE_RE.match(line)
+        if not kv_match:
+            continue
+        key = kv_match.group("key")
+        raw = kv_match.group("value")
+        data[key] = parse_tres_value(raw)
+    return data
+
+
+def update_tres_resource(text: str, updates: Dict[str, Any]) -> str:
+    lines = text.splitlines()
+    resource_start = None
+    resource_end = None
+    for idx, line in enumerate(lines):
+        section_match = SECTION_RE.match(line)
+        if not section_match:
+            continue
+        section_name = section_match.group("name")
+        if section_name == "resource":
+            resource_start = idx
+            continue
+        if resource_start is not None and resource_end is None:
+            resource_end = idx
+            break
+    if resource_start is None:
+        raise ValueError("Missing [resource] section.")
+    if resource_end is None:
+        resource_end = len(lines)
+
+    updated_keys: set[str] = set()
+    for idx in range(resource_start + 1, resource_end):
+        kv_match = KEY_VALUE_RE.match(lines[idx])
+        if not kv_match:
+            continue
+        key = kv_match.group("key")
+        if key not in updates:
+            continue
+        indent = kv_match.group("indent")
+        value = serialize_tres_value(updates[key])
+        lines[idx] = f"{indent}{key} = {value}"
+        updated_keys.add(key)
+
+    new_lines: List[str] = []
+    for key, value in updates.items():
+        if key in updated_keys:
+            continue
+        new_lines.append(f"{key} = {serialize_tres_value(value)}")
+    if new_lines:
+        lines[resource_end:resource_end] = new_lines
+
+    return "\n".join(lines) + "\n"
+
+
+def infer_schema(value: Any) -> Dict[str, Any]:
+    if isinstance(value, dict):
+        return {
+            "type": "object",
+            "fields": {key: infer_schema(val) for key, val in value.items()},
+        }
+    if isinstance(value, list):
+        if not value:
+            return {"type": "array", "items": {"type": "unknown"}}
+        item_schemas = [infer_schema(item) for item in value]
+        if all(item == item_schemas[0] for item in item_schemas):
+            return {"type": "array", "items": item_schemas[0]}
+        return {"type": "array", "items": item_schemas}
+    if isinstance(value, bool):
+        return {"type": "boolean"}
+    if isinstance(value, int):
+        return {"type": "integer"}
+    if isinstance(value, float):
+        return {"type": "number"}
+    if isinstance(value, str):
+        return {"type": "string"}
+    if value is None:
+        return {"type": "null"}
+    return {"type": "unknown"}
+
+
+def load_definition_file(path: Path) -> Any:
+    if path.suffix.lower() == ".json":
+        return json.loads(path.read_text(encoding="utf-8"))
+    if path.suffix.lower() == ".tres":
+        return load_tres_resource(path.read_text(encoding="utf-8"))
+    raise ValueError("Unsupported definition file.")
+
+
+def write_definition_file(path: Path, content: Any, paths: NdbsPaths) -> None:
+    if path.suffix.lower() == ".json":
+        backup_file(path, paths)
+        path.write_text(
+            json.dumps(content, indent=2, ensure_ascii=False) + "\n",
+            encoding="utf-8",
+        )
+        return
+    if path.suffix.lower() == ".tres":
+        if not isinstance(content, dict):
+            raise ValueError("TRES content must be an object.")
+        backup_file(path, paths)
+        updated = update_tres_resource(path.read_text(encoding="utf-8"), content)
+        path.write_text(updated, encoding="utf-8")
+        return
+    raise ValueError("Unsupported definition file.")
+
+
+def list_definition_files(paths: NdbsPaths) -> List[str]:
+    if not paths.definitions_root.exists():
+        raise FileNotFoundError("Definitions root not found.")
+    files = [
+        path.relative_to(paths.definitions_root).as_posix()
+        for path in paths.definitions_root.rglob("*")
+        if path.is_file() and path.suffix.lower() in ALLOWED_DEFINITION_EXTS
+    ]
+    return sorted(files)
+
+
+def list_rule_files(paths: NdbsPaths) -> List[str]:
+    if not paths.rules_root.exists():
+        return []
+    files = [
+        path.relative_to(paths.rules_root).as_posix()
+        for path in paths.rules_root.rglob("*.cs")
+        if path.is_file()
+    ]
+    return sorted(files)
+
+
+def to_camel_case(value: str) -> str:
+    parts = re.split(r"[^A-Za-z0-9]+", value)
+    camel = "".join(part[:1].upper() + part[1:] for part in parts if part)
+    if not camel:
+        return ""
+    if camel[0].isdigit():
+        return f"R{camel}"
+    return camel
+
+
+def render_rule_template(rule_id: str, class_name: str) -> str:
+    return (
+        "namespace Rules.Generated;\n"
+        "using Core.Interfaces;\n"
+        "using Models;\n"
+        "\n"
+        f"public sealed class {class_name} : IGameRule\n"
+        "{\n"
+        f"\tpublic string Id => \"rule:{rule_id}\";\n"
+        "\n"
+        "\tpublic void OnEvent(GameSession session, object gameEvent)\n"
+        "\t{\n"
+        "\t}\n"
+        "\n"
+        "\tpublic void ModifyStats(UnitModel unit, StatRequest request)\n"
+        "\t{\n"
+        "\t}\n"
+        "}\n"
+    )
+
+
+def create_rule(rule_id: str, paths: NdbsPaths) -> str:
+    rule_id = rule_id.strip()
+    if not re.fullmatch(r"[A-Za-z0-9_]+", rule_id):
+        raise ValueError("Rule id must be alphanumeric/underscore.")
+    class_name = f"Rule_{to_camel_case(rule_id)}"
+    if not class_name or class_name == "Rule_":
+        raise ValueError("Rule id is invalid.")
+    paths.rules_root.mkdir(parents=True, exist_ok=True)
+    path = paths.rules_root / f"{class_name}.cs"
+    if path.exists():
+        raise FileExistsError("Rule already exists.")
+    path.write_text(render_rule_template(rule_id, class_name), encoding="utf-8")
+    return path.name
diff --git a/tools/ndbs/server/pyproject.toml b/tools/ndbs/server/pyproject.toml
new file mode 100644
index 0000000..32de4e5
--- /dev/null
+++ b/tools/ndbs/server/pyproject.toml
@@ -0,0 +1,16 @@
+[project]
+name = "ndbs-server"
+version = "0.1.0"
+description = "NDBS FastAPI backend"
+requires-python = ">=3.14"
+dependencies = [
+    "fastapi>=0.115.0",
+    "uvicorn>=0.30.0",
+    "pydantic>=2.8.0",
+]
+
+[dependency-groups]
+dev = [
+    "httpx>=0.27.0",
+    "pytest>=8.2.2",
+]
diff --git a/tools/ndbs/server/tests/test_api.py b/tools/ndbs/server/tests/test_api.py
new file mode 100644
index 0000000..e470f68
--- /dev/null
+++ b/tools/ndbs/server/tests/test_api.py
@@ -0,0 +1,167 @@
+import json
+import sys
+from pathlib import Path
+
+import pytest
+
+SERVER_ROOT = Path(__file__).resolve().parents[1]
+sys.path.insert(0, str(SERVER_ROOT))
+
+from ndbs_core import (  # noqa: E402
+    NdbsPaths,
+    create_rule,
+    ensure_within_root,
+    infer_schema,
+    list_definition_files,
+    list_rule_files,
+    load_definition_file,
+    parse_tres_array,
+    parse_tres_value,
+    resolve_paths,
+    update_tres_resource,
+    write_definition_file,
+)
+
+
+def make_paths(tmp_path: Path) -> NdbsPaths:
+    project_root = tmp_path / "project"
+    project_root.mkdir()
+    (project_root / "project.godot").write_text("[gd_project]\n")
+
+    definitions_root = project_root / "resources" / "definitions"
+    definitions_root.mkdir(parents=True)
+
+    rules_root = project_root / "scripts" / "Rules" / "Generated"
+    rules_root.mkdir(parents=True)
+
+    backup_root = project_root / "tools" / "ndbs" / "backups"
+    backup_root.mkdir(parents=True)
+
+    web_root = project_root / "tools" / "ndbs" / "server" / "web"
+    web_root.mkdir(parents=True)
+    (web_root / "index.html").write_text("<html>ndbs</html>")
+
+    return NdbsPaths(
+        project_root=project_root,
+        definitions_root=definitions_root,
+        rules_root=rules_root,
+        backup_root=backup_root,
+        web_root=web_root,
+    )
+
+
+def seed_definitions(paths: NdbsPaths) -> None:
+    traits_path = paths.definitions_root / "traits.json"
+    traits_path.write_text(
+        json.dumps({"id": "core:trait_test", "value": 1}), encoding="utf-8"
+    )
+
+    tres_path = paths.definitions_root / "discipline_biology.tres"
+    tres_path.write_text(
+        "[gd_resource type=\"Resource\" format=3]\n"
+        "\n"
+        "[resource]\n"
+        "Id = \"core:discipline_test\"\n"
+        "NameFallback = \"Biology\"\n"
+        "Tags = [ \"discipline\", \"lab\" ]\n",
+        encoding="utf-8",
+    )
+
+
+def test_parse_tres_values() -> None:
+    assert parse_tres_value("\"hello\"") == "hello"
+    assert parse_tres_value("true") is True
+    assert parse_tres_value("42") == 42
+    assert parse_tres_array('[ "a", "b" ]') == ["a", "b"]
+
+
+def test_list_definitions_and_schema(tmp_path: Path) -> None:
+    paths = make_paths(tmp_path)
+    seed_definitions(paths)
+
+    files = list_definition_files(paths)
+    assert "traits.json" in files
+    assert "discipline_biology.tres" in files
+
+    content = load_definition_file(paths.definitions_root / "traits.json")
+    assert content["id"] == "core:trait_test"
+
+    schema = infer_schema(content)
+    assert schema["type"] == "object"
+    assert "id" in schema["fields"]
+
+
+def test_write_json_creates_backup(tmp_path: Path) -> None:
+    paths = make_paths(tmp_path)
+    seed_definitions(paths)
+
+    write_definition_file(
+        paths.definitions_root / "traits.json",
+        {"id": "core:trait_test", "value": 2},
+        paths,
+    )
+
+    saved = json.loads(
+        (paths.definitions_root / "traits.json").read_text(encoding="utf-8")
+    )
+    assert saved["value"] == 2
+    backups = list(paths.backup_root.rglob("traits.json"))
+    assert backups
+
+
+def test_tres_roundtrip(tmp_path: Path) -> None:
+    paths = make_paths(tmp_path)
+    seed_definitions(paths)
+
+    original = load_definition_file(paths.definitions_root / "discipline_biology.tres")
+    assert original["Tags"] == ["discipline", "lab"]
+
+    write_definition_file(
+        paths.definitions_root / "discipline_biology.tres",
+        {"Tags": ["alpha", "beta"], "NameFallback": "Bio 2"},
+        paths,
+    )
+
+    updated = load_definition_file(paths.definitions_root / "discipline_biology.tres")
+    assert updated["Tags"] == ["alpha", "beta"]
+    assert updated["NameFallback"] == "Bio 2"
+
+
+def test_update_tres_resource_adds_keys() -> None:
+    original = "[resource]\nId = \"core:test\"\n"
+    updated = update_tres_resource(original, {"NewKey": "Value"})
+    assert "NewKey" in updated
+
+
+def test_create_rule(tmp_path: Path) -> None:
+    paths = make_paths(tmp_path)
+
+    filename = create_rule("test_rule", paths)
+    assert filename.endswith(".cs")
+    rule_path = paths.rules_root / filename
+    assert rule_path.exists()
+    assert "rule:test_rule" in rule_path.read_text(encoding="utf-8")
+
+    rules = list_rule_files(paths)
+    assert filename in rules
+
+
+def test_ensure_within_root_rejects_traversal(tmp_path: Path) -> None:
+    paths = make_paths(tmp_path)
+    with pytest.raises(ValueError):
+        ensure_within_root(paths.definitions_root, "../evil.json", {".json"})
+
+
+def test_resolve_paths_defaults(tmp_path: Path, monkeypatch: pytest.MonkeyPatch) -> None:
+    project_root = tmp_path / "game"
+    project_root.mkdir()
+    (project_root / "project.godot").write_text("[gd_project]\n")
+    server_root = tmp_path / "server"
+    server_root.mkdir()
+
+    monkeypatch.chdir(server_root)
+    monkeypatch.setenv("NDBS_PROJECT_ROOT", str(project_root))
+
+    resolved = resolve_paths()
+    assert resolved.project_root == project_root
+    assert resolved.definitions_root.name == "definitions"
diff --git a/tools/ndbs/server/uv.lock b/tools/ndbs/server/uv.lock
new file mode 100644
index 0000000..3d005d3
--- /dev/null
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+sdist = { url = "https://files.pythonhosted.org/packages/c3/d1/8f3c683c9561a4e6689dd3b1d345c815f10f86acd044ee1fb9a4dcd0b8c5/uvicorn-0.40.0.tar.gz", hash = "sha256:839676675e87e73694518b5574fd0f24c9d97b46bea16df7b8c05ea1a51071ea", size = 81761, upload-time = "2025-12-21T14:16:22.45Z" }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/3d/d8/2083a1daa7439a66f3a48589a57d576aa117726762618f6bb09fe3798796/uvicorn-0.40.0-py3-none-any.whl", hash = "sha256:c6c8f55bc8bf13eb6fa9ff87ad62308bbbc33d0b67f84293151efe87e0d5f2ee", size = 68502, upload-time = "2025-12-21T14:16:21.041Z" },
+]
diff --git a/tools/ndbs/server/web/app.js b/tools/ndbs/server/web/app.js
new file mode 100644
index 0000000..5fb749f
--- /dev/null
+++ b/tools/ndbs/server/web/app.js
@@ -0,0 +1,280 @@
+const state = {
+  definitions: [],
+  rules: [],
+  activeType: null,
+  activeFile: null,
+};
+
+const elements = {
+  refreshButton: document.getElementById("refresh-button"),
+  filterInput: document.getElementById("filter-input"),
+  definitionsList: document.getElementById("definitions-list"),
+  rulesList: document.getElementById("rules-list"),
+  definitionsCount: document.getElementById("definitions-count"),
+  rulesCount: document.getElementById("rules-count"),
+  editorTitle: document.getElementById("editor-title"),
+  editorSubtitle: document.getElementById("editor-subtitle"),
+  editorTextarea: document.getElementById("editor-textarea"),
+  schemaSummary: document.getElementById("schema-summary"),
+  formatButton: document.getElementById("format-button"),
+  saveButton: document.getElementById("save-button"),
+  statusMessage: document.getElementById("status-message"),
+  newRuleInput: document.getElementById("new-rule-id"),
+  createRuleButton: document.getElementById("create-rule"),
+  buildButton: document.getElementById("build-button"),
+  buildOutput: document.getElementById("build-output"),
+};
+
+const fetchJson = async (url, options = {}) => {
+  const response = await fetch(url, {
+    headers: { "Content-Type": "application/json" },
+    ...options,
+  });
+  if (!response.ok) {
+    let detail = "Request failed.";
+    try {
+      const body = await response.json();
+      detail = body.detail || detail;
+    } catch (err) {
+      detail = response.statusText || detail;
+    }
+    throw new Error(detail);
+  }
+  return response.json();
+};
+
+const setStatus = (message, isError = false) => {
+  elements.statusMessage.textContent = message;
+  elements.statusMessage.classList.toggle("error", isError);
+};
+
+const clearSchema = () => {
+  elements.schemaSummary.innerHTML = "";
+  elements.schemaSummary.classList.add("hidden");
+};
+
+const renderSchema = (schema) => {
+  if (!schema || schema.type !== "object") {
+    clearSchema();
+    return;
+  }
+  const fields = Object.keys(schema.fields || {}).slice(0, 12);
+  elements.schemaSummary.innerHTML = "";
+  fields.forEach((field) => {
+    const chip = document.createElement("span");
+    chip.textContent = field;
+    elements.schemaSummary.appendChild(chip);
+  });
+  elements.schemaSummary.classList.toggle("hidden", fields.length === 0);
+};
+
+const createNavItem = (file, isActive, onClick) => {
+  const button = document.createElement("button");
+  button.className = "nav-item";
+  if (isActive) {
+    button.classList.add("active");
+  }
+  const label = document.createElement("span");
+  label.textContent = file;
+  button.appendChild(label);
+  button.addEventListener("click", () => onClick(file));
+  return button;
+};
+
+const renderLists = () => {
+  const filterValue = elements.filterInput.value.trim().toLowerCase();
+  const defFiles = state.definitions.filter((file) =>
+    file.toLowerCase().includes(filterValue),
+  );
+  const ruleFiles = state.rules.filter((file) =>
+    file.toLowerCase().includes(filterValue),
+  );
+
+  elements.definitionsList.innerHTML = "";
+  elements.rulesList.innerHTML = "";
+  defFiles.forEach((file) => {
+    elements.definitionsList.appendChild(
+      createNavItem(file, state.activeType === "definition" && state.activeFile === file, openDefinition),
+    );
+  });
+  ruleFiles.forEach((file) => {
+    elements.rulesList.appendChild(
+      createNavItem(file, state.activeType === "rule" && state.activeFile === file, openRule),
+    );
+  });
+
+  elements.definitionsCount.textContent = String(defFiles.length);
+  elements.rulesCount.textContent = String(ruleFiles.length);
+};
+
+const setEditorState = ({ title, subtitle, content, mode }) => {
+  elements.editorTitle.textContent = title;
+  elements.editorSubtitle.textContent = subtitle;
+  elements.editorTextarea.value = content;
+  elements.formatButton.classList.toggle("hidden", mode !== "definition");
+};
+
+const openDefinition = async (filename) => {
+  try {
+    setStatus("Loading definition...");
+    const [contentResponse, schemaResponse] = await Promise.all([
+      fetchJson(`/api/files/content?filename=${encodeURIComponent(filename)}`),
+      fetchJson(`/api/files/schema?filename=${encodeURIComponent(filename)}`),
+    ]);
+    state.activeType = "definition";
+    state.activeFile = filename;
+    renderLists();
+    const rawContent = JSON.stringify(contentResponse.content || {}, null, 2);
+    setEditorState({
+      title: filename,
+      subtitle: filename.endsWith(".tres") ? "Godot resource (tres)" : "JSON definition",
+      content: rawContent,
+      mode: "definition",
+    });
+    renderSchema(schemaResponse.schema);
+    setStatus("Definition loaded.");
+  } catch (err) {
+    setStatus(err.message || "Failed to load definition.", true);
+  }
+};
+
+const openRule = async (filename) => {
+  try {
+    setStatus("Loading rule...");
+    const response = await fetchJson(
+      `/api/rules/content?filename=${encodeURIComponent(filename)}`,
+    );
+    state.activeType = "rule";
+    state.activeFile = filename;
+    renderLists();
+    setEditorState({
+      title: filename,
+      subtitle: "C# rule source",
+      content: response.content || "",
+      mode: "rule",
+    });
+    clearSchema();
+    setStatus("Rule loaded.");
+  } catch (err) {
+    setStatus(err.message || "Failed to load rule.", true);
+  }
+};
+
+const refreshAll = async () => {
+  try {
+    setStatus("Refreshing lists...");
+    const [definitions, rules] = await Promise.all([
+      fetchJson("/api/files/definitions"),
+      fetchJson("/api/rules/list"),
+    ]);
+    state.definitions = definitions.files || [];
+    state.rules = rules.files || [];
+    renderLists();
+    setStatus("Lists refreshed.");
+  } catch (err) {
+    setStatus(err.message || "Failed to refresh.", true);
+  }
+};
+
+const saveCurrent = async () => {
+  if (!state.activeType || !state.activeFile) {
+    setStatus("Select a file before saving.", true);
+    return;
+  }
+  if (state.activeType === "definition") {
+    let parsed;
+    try {
+      parsed = JSON.parse(elements.editorTextarea.value);
+    } catch (err) {
+      setStatus("Invalid JSON. Fix errors before saving.", true);
+      return;
+    }
+    try {
+      await fetchJson("/api/files/content", {
+        method: "POST",
+        body: JSON.stringify({
+          filename: state.activeFile,
+          content: parsed,
+        }),
+      });
+      setStatus("Definition saved.");
+    } catch (err) {
+      setStatus(err.message || "Failed to save definition.", true);
+    }
+    return;
+  }
+
+  try {
+    await fetchJson("/api/rules/content", {
+      method: "POST",
+      body: JSON.stringify({
+        filename: state.activeFile,
+        content: elements.editorTextarea.value,
+      }),
+    });
+    setStatus("Rule saved.");
+  } catch (err) {
+    setStatus(err.message || "Failed to save rule.", true);
+  }
+};
+
+const formatJson = () => {
+  if (state.activeType !== "definition") {
+    return;
+  }
+  try {
+    const parsed = JSON.parse(elements.editorTextarea.value);
+    elements.editorTextarea.value = JSON.stringify(parsed, null, 2);
+    setStatus("Formatted JSON.");
+  } catch (err) {
+    setStatus("Invalid JSON. Cannot format.", true);
+  }
+};
+
+const createRule = async () => {
+  const ruleId = elements.newRuleInput.value.trim();
+  if (!ruleId) {
+    setStatus("Enter a rule id first.", true);
+    return;
+  }
+  try {
+    const response = await fetchJson("/api/rules/create", {
+      method: "POST",
+      body: JSON.stringify({ rule_id: ruleId }),
+    });
+    elements.newRuleInput.value = "";
+    await refreshAll();
+    if (response.filename) {
+      await openRule(response.filename);
+    }
+    setStatus("Rule created.");
+  } catch (err) {
+    setStatus(err.message || "Failed to create rule.", true);
+  }
+};
+
+const buildGame = async () => {
+  try {
+    elements.buildOutput.textContent = "Running build...";
+    const response = await fetchJson("/api/build", { method: "POST" });
+    const output = [response.stdout, response.stderr].filter(Boolean).join("\n");
+    elements.buildOutput.textContent = output || "Build finished.";
+    setStatus(response.success ? "Build complete." : "Build completed with errors.");
+  } catch (err) {
+    elements.buildOutput.textContent = "Build failed to start.";
+    setStatus(err.message || "Build failed.", true);
+  }
+};
+
+const init = () => {
+  elements.refreshButton.addEventListener("click", refreshAll);
+  elements.filterInput.addEventListener("input", renderLists);
+  elements.saveButton.addEventListener("click", saveCurrent);
+  elements.formatButton.addEventListener("click", formatJson);
+  elements.createRuleButton.addEventListener("click", createRule);
+  elements.buildButton.addEventListener("click", buildGame);
+  refreshAll();
+  setStatus("Ready.");
+};
+
+init();
diff --git a/tools/ndbs/server/web/fonts/AlibabaPuHuiTi-3-65-Medium.ttf b/tools/ndbs/server/web/fonts/AlibabaPuHuiTi-3-65-Medium.ttf
new file mode 100644
index 0000000..38ee60f
Binary files /dev/null and b/tools/ndbs/server/web/fonts/AlibabaPuHuiTi-3-65-Medium.ttf differ
diff --git a/tools/ndbs/server/web/fonts/AlibabaPuHuiTi-3-85-Bold.ttf b/tools/ndbs/server/web/fonts/AlibabaPuHuiTi-3-85-Bold.ttf
new file mode 100644
index 0000000..7edd4e5
Binary files /dev/null and b/tools/ndbs/server/web/fonts/AlibabaPuHuiTi-3-85-Bold.ttf differ
diff --git a/tools/ndbs/server/web/fonts/KenneyFuture.ttf b/tools/ndbs/server/web/fonts/KenneyFuture.ttf
new file mode 100644
index 0000000..17e2b6c
Binary files /dev/null and b/tools/ndbs/server/web/fonts/KenneyFuture.ttf differ
diff --git a/tools/ndbs/server/web/icon.svg b/tools/ndbs/server/web/icon.svg
new file mode 100644
index 0000000..9d8b7fa
--- /dev/null
+++ b/tools/ndbs/server/web/icon.svg
@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="128" height="128"><rect width="124" height="124" x="2" y="2" fill="#363d52" stroke="#212532" stroke-width="4" rx="14"/><g fill="#fff" transform="translate(12.322 12.322)scale(.101)"><path d="M105 673v33q407 354 814 0v-33z"/><path fill="#478cbf" d="m105 673 152 14q12 1 15 14l4 67 132 10 8-61q2-11 15-15h162q13 4 15 15l8 61 132-10 4-67q3-13 15-14l152-14V427q30-39 56-81-35-59-83-108-43 20-82 47-40-37-88-64 7-51 8-102-59-28-123-42-26 43-46 89-49-7-98 0-20-46-46-89-64 14-123 42 1 51 8 102-48 27-88 64-39-27-82-47-48 49-83 108 26 42 56 81zm0 33v39c0 276 813 276 814 0v-39l-134 12-5 69q-2 10-14 13l-162 11q-12 0-16-11l-10-65H446l-10 65q-4 11-16 11l-162-11q-12-3-14-13l-5-69z"/><path d="M483 600c0 34 58 34 58 0v-86c0-34-58-34-58 0z"/><circle cx="725" cy="526" r="90"/><circle cx="299" cy="526" r="90"/></g><g fill="#414042" transform="translate(12.322 12.322)scale(.101)"><circle cx="307" cy="532" r="60"/><circle cx="717" cy="532" r="60"/></g></svg>
\ No newline at end of file
diff --git a/tools/ndbs/server/web/index.html b/tools/ndbs/server/web/index.html
new file mode 100644
index 0000000..8a075a7
--- /dev/null
+++ b/tools/ndbs/server/web/index.html
@@ -0,0 +1,82 @@
+<!doctype html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <link rel="icon" href="/static/icon.svg" type="image/svg+xml" />
+    <link rel="stylesheet" href="/static/styles.css" />
+    <title>NDBS Console</title>
+  </head>
+  <body>
+    <div class="app-shell">
+      <aside class="sidebar">
+        <div class="brand">
+          <div class="brand-title">NDBS Console</div>
+          <div class="brand-subtitle">Single-service balance editor</div>
+        </div>
+        <div class="quick-actions">
+          <button id="refresh-button" class="ghost">Refresh</button>
+        </div>
+        <input id="filter-input" class="filter-input" placeholder="Filter files" />
+        <div class="list-section">
+          <div class="section-header">
+            <span>Definitions</span>
+            <span id="definitions-count" class="section-count">0</span>
+          </div>
+          <div id="definitions-list" class="nav-list"></div>
+        </div>
+        <div class="list-section">
+          <div class="section-header">
+            <span>Rules</span>
+            <span id="rules-count" class="section-count">0</span>
+          </div>
+          <div id="rules-list" class="nav-list"></div>
+        </div>
+      </aside>
+      <main class="main">
+        <section class="panel hero">
+          <div class="hero-top">NDBS 2.0</div>
+          <h1>Numerical design studio</h1>
+          <p>
+            Edit JSON and TRES definitions, generate new rule scripts, and sanity-check
+            builds without running a separate frontend stack.
+          </p>
+        </section>
+
+        <section class="panel controls">
+          <div class="panel-title">Rule controls</div>
+          <div class="control-row">
+            <input id="new-rule-id" class="text-input" placeholder="new_rule_id" />
+            <button id="create-rule">Create</button>
+            <button id="build-button" class="ghost">Verify build</button>
+          </div>
+          <div id="build-output" class="build-output"></div>
+        </section>
+
+        <section class="panel editor-panel">
+          <div class="editor-header">
+            <div>
+              <div id="editor-title" class="panel-title">No file selected</div>
+              <div id="editor-subtitle" class="panel-subtitle">
+                Pick a definition or rule from the sidebar.
+              </div>
+            </div>
+            <div class="editor-actions">
+              <button id="format-button" class="ghost">Format</button>
+              <button id="save-button">Save</button>
+            </div>
+          </div>
+          <div id="schema-summary" class="schema-summary hidden"></div>
+          <textarea
+            id="editor-textarea"
+            class="code-area"
+            spellcheck="false"
+            placeholder="Open a file to start editing."
+          ></textarea>
+          <div id="status-message" class="status-message"></div>
+        </section>
+      </main>
+    </div>
+    <script src="/static/app.js"></script>
+  </body>
+</html>
diff --git a/tools/ndbs/server/web/styles.css b/tools/ndbs/server/web/styles.css
new file mode 100644
index 0000000..a9f1c52
--- /dev/null
+++ b/tools/ndbs/server/web/styles.css
@@ -0,0 +1,394 @@
+@font-face {
+  font-family: "AlibabaPuHuiTi";
+  src: url("/static/fonts/AlibabaPuHuiTi-3-65-Medium.ttf") format("truetype");
+  font-weight: 500;
+  font-style: normal;
+  font-display: swap;
+}
+
+@font-face {
+  font-family: "AlibabaPuHuiTi";
+  src: url("/static/fonts/AlibabaPuHuiTi-3-85-Bold.ttf") format("truetype");
+  font-weight: 700;
+  font-style: normal;
+  font-display: swap;
+}
+
+@font-face {
+  font-family: "KenneyFuture";
+  src: url("/static/fonts/KenneyFuture.ttf") format("truetype");
+  font-weight: 700;
+  font-style: normal;
+  font-display: swap;
+}
+
+:root {
+  color-scheme: light;
+  --bg-0: #f5f1ea;
+  --bg-1: #fff0d6;
+  --bg-2: #e3f4ec;
+  --ink-0: #182126;
+  --ink-1: #2b353a;
+  --ink-2: #556068;
+  --accent-0: #f59e0b;
+  --accent-1: #0f766e;
+  --accent-2: #d1495b;
+  --panel: rgba(255, 255, 255, 0.86);
+  --panel-border: rgba(18, 33, 38, 0.12);
+  --shadow: 0 24px 50px rgba(12, 20, 28, 0.15);
+}
+
+* {
+  box-sizing: border-box;
+}
+
+body {
+  margin: 0;
+  min-height: 100vh;
+  font-family: "AlibabaPuHuiTi", "Noto Serif", serif;
+  color: var(--ink-0);
+  background: radial-gradient(circle at 12% 18%, var(--bg-1) 0%, var(--bg-0) 50%, var(--bg-2) 100%);
+}
+
+button,
+input,
+textarea {
+  font-family: inherit;
+}
+
+button {
+  border: 1px solid rgba(24, 33, 38, 0.18);
+  background: rgba(245, 158, 11, 0.86);
+  color: var(--ink-0);
+  border-radius: 10px;
+  padding: 8px 14px;
+  cursor: pointer;
+  font-size: 13px;
+  transition: transform 0.2s ease, box-shadow 0.2s ease;
+}
+
+button:hover {
+  transform: translateY(-1px);
+  box-shadow: 0 6px 16px rgba(0, 0, 0, 0.12);
+}
+
+button.ghost {
+  background: transparent;
+}
+
+input.text-input,
+input.filter-input {
+  width: 100%;
+  border: 1px solid rgba(18, 33, 38, 0.16);
+  border-radius: 12px;
+  padding: 8px 10px;
+  background: rgba(255, 255, 255, 0.8);
+  font-size: 13px;
+}
+
+.app-shell {
+  position: relative;
+  display: grid;
+  grid-template-columns: 320px 1fr;
+  gap: 24px;
+  min-height: 100vh;
+  padding: 24px;
+}
+
+.app-shell::before,
+.app-shell::after {
+  content: "";
+  position: absolute;
+  z-index: 0;
+  border-radius: 999px;
+  filter: blur(2px);
+}
+
+.app-shell::before {
+  width: 420px;
+  height: 420px;
+  top: -120px;
+  left: -120px;
+  background: radial-gradient(circle, rgba(245, 158, 11, 0.28) 0%, rgba(245, 158, 11, 0) 70%);
+}
+
+.app-shell::after {
+  width: 520px;
+  height: 520px;
+  bottom: -200px;
+  right: -180px;
+  background: radial-gradient(circle, rgba(15, 118, 110, 0.25) 0%, rgba(15, 118, 110, 0) 72%);
+}
+
+.sidebar,
+.main {
+  position: relative;
+  z-index: 1;
+}
+
+.sidebar {
+  background: var(--panel);
+  border: 1px solid var(--panel-border);
+  border-radius: 20px;
+  box-shadow: var(--shadow);
+  overflow: hidden;
+  padding: 20px 18px;
+  display: flex;
+  flex-direction: column;
+  gap: 16px;
+}
+
+.brand-title {
+  font-family: "KenneyFuture", "AlibabaPuHuiTi", serif;
+  font-size: 20px;
+  letter-spacing: 0.05em;
+}
+
+.brand-subtitle {
+  font-size: 12px;
+  color: var(--ink-2);
+  margin-top: 4px;
+}
+
+.quick-actions {
+  display: flex;
+  gap: 10px;
+  flex-wrap: wrap;
+}
+
+.list-section {
+  display: flex;
+  flex-direction: column;
+  gap: 8px;
+}
+
+.section-header {
+  display: flex;
+  justify-content: space-between;
+  align-items: center;
+  font-size: 12px;
+  text-transform: uppercase;
+  letter-spacing: 0.12em;
+  color: var(--ink-2);
+}
+
+.section-count {
+  font-size: 11px;
+  background: rgba(15, 118, 110, 0.16);
+  padding: 2px 8px;
+  border-radius: 999px;
+}
+
+.nav-list {
+  display: flex;
+  flex-direction: column;
+  gap: 8px;
+  max-height: 280px;
+  overflow: auto;
+  padding-right: 6px;
+}
+
+.nav-item {
+  border: 1px solid rgba(18, 33, 38, 0.12);
+  background: rgba(255, 255, 255, 0.82);
+  border-radius: 12px;
+  padding: 8px 10px;
+  text-align: left;
+  cursor: pointer;
+  transition: transform 0.2s ease, border-color 0.2s ease;
+  animation: list-in 420ms ease-out both;
+}
+
+.nav-item.active {
+  border-color: rgba(245, 158, 11, 0.8);
+  background: rgba(255, 240, 214, 0.95);
+}
+
+.nav-item:hover {
+  transform: translateY(-1px);
+  border-color: rgba(245, 158, 11, 0.5);
+}
+
+.nav-item span {
+  font-size: 13px;
+  color: var(--ink-1);
+  word-break: break-word;
+}
+
+.main {
+  display: flex;
+  flex-direction: column;
+  gap: 20px;
+}
+
+.panel {
+  background: var(--panel);
+  border-radius: 18px;
+  border: 1px solid var(--panel-border);
+  box-shadow: var(--shadow);
+  padding: 20px 22px;
+  animation: float-in 420ms ease-out both;
+}
+
+.panel-title {
+  font-family: "KenneyFuture", "AlibabaPuHuiTi", serif;
+  font-size: 18px;
+  letter-spacing: 0.04em;
+}
+
+.panel-subtitle {
+  color: var(--ink-2);
+  font-size: 13px;
+  margin-top: 4px;
+}
+
+.hero {
+  background: linear-gradient(135deg, rgba(255, 240, 214, 0.95) 0%, rgba(255, 255, 255, 0.9) 40%, rgba(227, 244, 236, 0.9) 100%);
+}
+
+.hero-top {
+  text-transform: uppercase;
+  letter-spacing: 0.18em;
+  font-size: 11px;
+  color: var(--ink-2);
+}
+
+.hero h1 {
+  font-family: "KenneyFuture", "AlibabaPuHuiTi", serif;
+  font-size: 34px;
+  margin: 10px 0 8px;
+}
+
+.hero p {
+  margin: 0;
+  color: var(--ink-1);
+  max-width: 540px;
+}
+
+.controls {
+  display: flex;
+  flex-direction: column;
+  gap: 12px;
+}
+
+.control-row {
+  display: flex;
+  gap: 12px;
+  flex-wrap: wrap;
+  align-items: center;
+}
+
+.editor-panel {
+  display: flex;
+  flex-direction: column;
+  gap: 14px;
+}
+
+.editor-header {
+  display: flex;
+  justify-content: space-between;
+  align-items: center;
+  gap: 16px;
+  flex-wrap: wrap;
+}
+
+.editor-actions {
+  display: flex;
+  gap: 10px;
+}
+
+.code-area {
+  width: 100%;
+  min-height: 420px;
+  resize: vertical;
+  padding: 16px;
+  border-radius: 14px;
+  border: 1px solid rgba(24, 33, 38, 0.2);
+  background: rgba(247, 247, 244, 0.9);
+  color: var(--ink-0);
+  font-family: "Courier New", monospace;
+  font-size: 13px;
+  line-height: 1.5;
+  outline: none;
+}
+
+.schema-summary {
+  display: flex;
+  gap: 10px;
+  align-items: center;
+  flex-wrap: wrap;
+}
+
+.schema-summary span {
+  padding: 3px 8px;
+  border-radius: 999px;
+  background: rgba(15, 118, 110, 0.15);
+  color: var(--ink-1);
+  font-size: 12px;
+}
+
+.schema-summary.hidden {
+  display: none;
+}
+
+.status-message {
+  font-size: 13px;
+  color: var(--ink-2);
+}
+
+.status-message.error {
+  color: var(--accent-2);
+}
+
+.build-output {
+  padding: 12px;
+  border-radius: 12px;
+  background: rgba(23, 37, 44, 0.06);
+  max-height: 200px;
+  overflow: auto;
+  font-size: 12px;
+  white-space: pre-wrap;
+}
+
+.hidden {
+  display: none;
+}
+
+@keyframes float-in {
+  from {
+    opacity: 0;
+    transform: translateY(12px);
+  }
+  to {
+    opacity: 1;
+    transform: translateY(0);
+  }
+}
+
+@keyframes list-in {
+  from {
+    opacity: 0;
+    transform: translateY(10px);
+  }
+  to {
+    opacity: 1;
+    transform: translateY(0);
+  }
+}
+
+@media (max-width: 960px) {
+  .app-shell {
+    grid-template-columns: 1fr;
+  }
+
+  .nav-list {
+    max-height: 220px;
+  }
+}
+
+@media (prefers-reduced-motion: reduce) {
+  * {
+    animation: none !important;
+    transition: none !important;
+  }
+}