diff --git a/app.py b/app.py
index 5318af9..b2416cb 100644
--- a/app.py
+++ b/app.py
@@ -195,21 +195,47 @@ class OutlineRequest(BaseModel):
     prompt: Optional[str] = None
 
 
-def length_convert(length: Optional[str]) -> str:
+def length_convert(length: Optional[str]):
+    """将篇幅解析为 {target, max}：target 为建议目标字数，max 为硬上限。"""
     if length == "短":
-        return "1000字"
+        return {"target": 700, "max": 1000}
     if length == "中":
-        return "1000-2000字"
+        return {"target": 2500, "max": 3000}
     if length == "长":
-        return "2000-5000字"
+        return {"target": 4500, "max": 5000}
+    # 兜底：从自定义篇幅字符串里解析出最大字数
+    if length:
+        nums = re.findall(r"\d+", length)
+        if nums:
+            max_chars = int(nums[-1])
+            return {"target": int(max_chars * 0.8), "max": max_chars}
+    return None
+
+
+def length_display(length: Optional[str]) -> str:
+    """模板 {length} 占位符用的字符串。"""
+    info = length_convert(length)
+    if info:
+        return f"{info['target']}字左右（不超过{info['max']}字）"
     return length or ""
 
 
+def build_length_instruction(length: Optional[str]) -> str:
+    """把 target/max 写进提示词：建议目标 + 硬上限 + 优先级。"""
+    info = length_convert(length)
+    if not info:
+        return ""
+    return (
+        f"全文建议写到{info['target']}字左右，绝对不得超过{info['max']}字；"
+        "字数为硬性要求，不得注水或重复凑字数。"
+    )
+
+
 def build_write_prompt(request: WriteRequest) -> str:
     prompt = request.prompt or ""
-    length = length_convert(request.length)
     template = request.template or ""
-    content = f"请生成一篇字数在{length}的{template}，字数严格遵守该规则，并且不能超过给定字数范围。{prompt}"
+    length_instruction = build_length_instruction(request.length)
+    content = f"请撰写一篇{template}。{length_instruction}{prompt}"
     prompt_template = TEMPLATE_DICT.get(template)
     if not prompt_template:
         raise HTTPException(status_code=400, detail=f"不支持的写作模板: {template}")
@@ -221,7 +247,7 @@ def build_write_prompt(request: WriteRequest) -> str:
     return content+prompt_template.format(
         role=request.role or "",
         title=title,
-        length=length_convert(request.length),
+        length=length_display(request.length),
         requirement=request.requirement or "",
         references=request.references or "",
         outline=request.outline or "",
@@ -267,7 +293,7 @@ def build_outline_prompt(request: OutlineRequest) -> str:
         role=request.role or "",
         template=template,
         title=title,
-        length=length_convert(request.length),
+        length=length_display(request.length),
         requirement=request.requirement or "",
         references=request.references or "",
     )
diff --git a/requirements.txt b/requirements.txt
index 1b7a7e6..820171f 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -4,41 +4,103 @@
 langchain
 langchain-core
 langchain-openai
+langchain-protocol
 langgraph
 langgraph-checkpoint
 langgraph-checkpoint-postgres
+langgraph-prebuilt
+langgraph-sdk
+langsmith
 
 # HTTP客户端
 httpx
+httpcore
+httptools
+h11
 requests
+requests-toolbelt
+urllib3
 
 # 数据处理
 pydantic
-typing-extensions
+pydantic_core
+typing_extensions
+typing-inspection
 numpy
+scipy
 
 # 其他工具
 python-dotenv
+python-dateutil
+pytz
+PyYAML
+types-PyYAML
+tenacity
+tqdm
+click
+json_repair
+jsonpatch
+jsonpointer
+orjson
+ormsgpack
+xxhash
+zstandard
+uuid_utils
+packaging
+regex
+six
+anyio
+sniffio
+certifi
+charset-normalizer
+idna
+distro
+exceptiongroup
+fsspec
+runlike
+pyahocorasick
 
 # FastAPI 相关
 fastapi
-uvicorn[standard]
+starlette
+uvicorn
+uvloop
+watchfiles
+websockets
+python-multipart
 
 # Neo4j 图数据库
 neo4j
+neo4j-graphrag
 
 # PostgreSQL 支持
-psycopg[binary]
+psycopg
+psycopg-binary
 psycopg-pool
 
 # OpenAI API
 openai
 tiktoken
+jiter
 
 # Word 文档生成
 python-docx
+lxml
+# LaTeX 公式转 Word 原生公式(OMML)，缺失时会回退成模糊图片
+latex2mathml
 
 # PDF 生成相关
 matplotlib
 Pillow
+contourpy
+cycler
+fonttools
+kiwisolver
+pyparsing
+pymupdf
+pypdf
 
+# 其他依赖
+aiofiles
+annotated-doc
+annotated-types